Chapter  13:  Quality Determinants of Mammography: Clinical Practice Guideline Number 13

Purpose and Scope

Mammography is an x-ray examination of the breasts for the detection of breast cancer. In 1992 an estimated 23.5 million mammograms were performed in the United States at a cost of about $2.5 billion (Houn and Brown, 1994). The purpose of this clinical practice guideline is to identify the elements of high-quality mammography. The guideline was developed by the Quality Determinants of Mammography Panel with support from the Agency for Health Care Policy and Research (AHCPR). Members of the panel included radiologists, radiologic technologists, medical physicists, family practice physicians, a nurse, an obstetrician-gynecologist, a surgeon, an internist/oncologist, a pathologist, and consumer representatives.

Screening mammography is an x-ray examination to detect unsuspected breast cancer at an early stage in asymptomatic women. It usually consists of two views of each breast: a mediolateral oblique view and a craniocaudal view. Screening mammography is performed by a radiologic technologist, often without an interpreting physician present. Screening mammograms may be interpreted in batches; interpretation usually occurs within 24 hours of the examination. If the result of a screening mammogram is equivocal or suspicious, additional imaging or breast biopsy may be recommended. Screening mammography has been shown effective in reducing deaths due to breast cancer (Chu, Smart, and Tarone, 1988; Hurley and Kaldor, 1992; Morrison, Brisson, and Khalid, 1988; Seidman, Gelb, Silverberg et al., 1987; Shapiro, 1977; Shapiro, Strax, and Venet, 1971; Shapiro, Venet, and Strax, 1988; Tabar, Fagerberg, Day et al., 1992; Tabar, Fagerberg, Duffy et al., 1989 and 1992; Tabar, Fagerberg, Gad et al., 1985; Verbeek, Hendriks, Holland et al., 1984). Screening mammography can be provided in several ways-general mammography facilities, dedicated screening mammography fixed sites, and mobile units. The expected parameters of quality should be the same for each setting.

Diagnostic mammography (also called problem-solving mammography or consultative mammography) is an x-ray examination to evaluate abnormal physical findings in the breasts, abnormal findings on a screening mammogram, or special cases such as breast implants. Abnormal physical findings include palpable masses, spontaneous nipple discharge, nipple retraction, and skin changes. Diagnostic mammography is usually performed under the onsite supervision of a qualified interpreting physician. Although online interpretation is desirable for diagnostic mammography, it may not be possible at all times, as in rural areas, or where requirements for online interpretation could affect accessibility.

The incidence of breast cancer in the United States has increased steadily over the last two decades. Current trends suggest that 1 womanin 8 will have breast cancer during her lifetime and 1 woman in 33 will die from breast cancer (Feuer, Wun, Boring et al., 1993; Harris, Lippman, Veronesi et al., 1992). Mammography is the only detection technique shown to reduce breast cancer mortality: in seven major studies, early detection of breast cancer through screening mammography resulted in reduced mortality, particularly in older women. Early detection means detection of a primary breast cancer when small (less than approximately 1.5 centimeters in diameter). In such cases, the likelihood of the cancer having spread beyond the breast is low and the prognosis for women receiving proper treatment is good (Tabar, Fagerberg, Duffy et al., 1992). Early detection of breast cancer by screening mammography also affords a greater possibility of breast conservation.

For mammography to reduce mortality from breast cancer in the general population, the procedure must be sensitive enough to detect the disease and screening must be performed at regular intervals on a large fraction of the target population. Poor-quality mammography reduces the sensitivity and specificity of the screening test. Adverse effects of poor-quality mammography include missed breast cancers (especially early cancers for which the prognosis is good), a false sense of security, unnecessary biopsies, unnecessary anxiety and suffering, and unnecessary radiation exposure.

The use of dedicated, up-to-date equipment is key to the performance of high-quality mammography. Quality mammography can result only if qualified personnel use and maintain dedicated equipment.

Many groups of people contribute to the delivery of high-quality mammography: physicians and other health care providers who refer women and patients for mammography are denoted by the term "providers" to distinguish them from personnel who supply mammography (interpreting physicians, radiologic technologists, and medical physicists), operators of mammography facilities, and support staff such as mammography facility schedulers and receptionists and mammography equipment service personnel. This guideline addresses specific recommendations for each of these groups. There is a shared responsibility to communicate information.

Also important are the sensitive treatment of women and patients receiving mammography and prompt, effective communication of results. A clear understanding of information conveyed at all stages of mammography is not only vital to peace of mind but may also increase the likelihood of compliance with regular screening or recommended followup.

The panel spent a great deal of time deliberating the issue of communication of results. It was looked at from a variety of viewpoints because panel members included referring providers, interpreting physicians, and consumers. However, the overriding concern was determined to be what was in the best interest of the woman having mammography. The possibility that a woman might not receive her abnormal mammography results was considered unacceptable. The guideline statements regarding communication were carefully crafted with the ultimate goal of a reduction in mortality due to breast cancer.

The chain of events involved in mammography often is begun by a health care provider who refers a woman or patient for the procedure. However, many women go for mammography without a referral from a health care provider. In this guideline, women are considered self-requesting if they schedule mammography independently but are able to name a personal provider willing to be notified of the results; women are considered self-referred if they schedule mammography independently and do not have a health care provider.

Issues intentionally not addressed in this guideline are the age at which screening mammography should begin, the intervals at which screening mammography should be performed, breast biopsy techniques, and breast cancer treatment methods. Although these are important issues, they were considered outside the scope of this guideline. The panel is strongly and unanimously of the opinion that both screening and diagnostic mammography should always be of the highest quality whenever the procedure is performed, without regard to the age or characteristics of the women involved.

This guideline concerns the need for high-quality mammography for all women, regardless of age, race, ethnicity, sexual orientation, socioeconomic status, educational level, disability, or geographic area. It is hoped that individual health care providers will be able to adapt the guideline to their local population and clinical setting.

Background to Guideline Development

The technical quality of mammography improved during the 1980s as conventional x-ray units were replaced with dedicated mammography systems and direct-film or conventional screen-film image receptors were replaced with screen-film receptors designed specifically for mammography. In the mid-1980s, however, it became apparent that despite these technical advances, image quality and breast radiation doses from mammography varied greatly. This recognition led to the establishment of voluntary mammography quality standards through the American College of Radiology (ACR) Mammography Accreditation Program (MAP) (McLelland, Hendrick, Zinninger et al., 1991). In 1990, Congress passed legislation authorizing Medicare coverage of screening mammography; facilities seeking Medicare reimbursement were required to register with the Health Care Financing Administration (HCFA) and meet quality standards similar to those of the ACR MAP. Federal inspections of Medicare-registered screening facilities began in 1992. Several States have passed legislation requiring mammography facilities to meet quality standards and submit to regular inspections by State radiation control inspectors.

Recognizing the need for uniform national standards, Congress passed the Mammography Quality Standards Act (MQSA) in 1992. This Act, which is effective October 1, 1994, requires that, to operate legally, all mammography facilities in the United States must meet minimum quality standards for personnel, equipment, and recordkeeping and be certified by the Food and Drug Administration (FDA). Facilities must obtain accreditation through an FDA-approved accreditation body. Inspection and certification of mammography facilities is a responsibility of FDA. MQSA quality standards supersede HCFA's requirements for mammography facilities receiving Medicare reimbursement. Veterans Health Administration facilities have their own mammography quality program that parallels MQSA and do not require FDA certification.

The intent of both this clinical practice guideline and MQSA is to promote high-quality mammography. MQSA requirements and guideline statements may vary slightly because of the inherent differences between regulations and guidelines. The panel urges mammography facilities to adopt the recommendations presented in this guideline even when they may exceed MQSA requirements. However, facilities will be inspected against and must comply with the MQSA requirements in order to be certified to perform mammography beginning October 1, 1994.

Organization of Guideline

The guideline first addresses quality-related activities before, during, and after the mammography examination. Subsequent chapters address the responsibilities of mammography facilities; the qualifications and responsibilities of mammography facility personnel; information that health care providers who refer women or patients for mammography should be aware of; possible adverse consequences and other problems associated with mammography; and the effectiveness of other imaging modalities in detecting breast cancer.

Methodology for Guideline Development

AHCPR published in the Federal Register a notice requesting nominations for a multidisciplinary panel to develop this guideline. Prerequisites for panel membership were significant expertise and experience in a discipline relevant to mammography. Information about 116 nominees was reviewed and candidates were screened for conflict of interest. The AHCPR administrator appointed 2 co-chairs and 13 panel members. The panel also used the technical expertise of six consultants. The panel had five 2 1/2 day meetings over a 14-month period from July 1992 until September 1993.

The panel followed the AHCPR methodology for guidelines based on evidence (Eddy, 1992) and focused on outcomes. The guideline development process began with a detailed identification of important questions related to the outcome of high-quality mammography.

On the basis of these questions, a thorough search of the medical literature was performed by the National Library of Medicine. The 20 bibliographic databases searched and the search strategies are detailed in the Guideline Technical Report. The criteria for the literature search were peer-reviewed medical literature (in English or with an English abstract) on mammography and breast imaging over the period 1980-92, excluding animal studies. The panel also considered other literature, including reviews, book chapters, manuals, non-peer-reviewed conference syllabi, and more recent studies that were brought to the panel's attention. The initial searches identified 6,467 abstracts, from which 1,500 works were obtained, and panel members identified additional literature. Approximately 500 individual works are cited in the Guideline Technical Report and approximately 300 in the Clinical Practice Guideline.

Each piece of literature was reviewed by at least one panel member or consultant. The panel was divided into working groups on the basis of the questions. The groups reviewed the literature, extracted data, wrote the guideline statements during and between panel meetings, and reported their results back to the full panel. A summary sheet was completed for each question to provide information about the quantity and quality of the medical literature, the strength of evidence for each guideline statement, and recommendations for research. Tables were constructed that detailed the evidence based on data extracted from the articles reviewed for each question.

The type of evidence available varied, depending on the topic:

• The medical audit section is based on cohort studies of groups of women who were screened and followed to determine false positives and false negatives. These cohort studies are the most appropriate kind of evidence for this question.

• The technical sections on equipment are based on well-designed experimental evidence.

• Evidence on other imaging modalities is based either on studies that compared mammography with another imaging modality (for screening or diagnostic examinations) or on cohort studies.

• Other evidence, such as on pain, comes from prospective epidemiological studies.

• Information in Chapter 2, "Activities Before the Examination," and in the section "Communicating Results" in Chapter 4 comes from the social sciences literature, which was based on qualitative and descriptive research.

Panel Recommendations and Levels of Evidence

The characterization of guideline statements as strong recommendations, recommendations, or options is based on the panel's opinion of how essential these steps are to achieve high-quality mammography.

The guideline statements are ranked by the panel as follows:

• Strong recommendations are guideline statements that deal with elements of mammography that the panel considers essential to good practice.

• Recommendations are statements that deal with elements of mammography that the panel considers attainable in most but not all mammography facilities.

• Options are statements of a less compelling nature that cannot be justified as recommendations.

Each guideline statement is rated for strength of evidence, as indicated by a letter code:

• A means the statement is supported by strong or extensive research-based evidence.

• B means the statement is supported by some research-based evidence and by panel expert opinion.

• C means the statement is based on panel experience and expert opinion.

Consensus (a process of discussion among panel members to arrive at mutually acceptable decisions) was used in developing the guideline statement, its ranking, and its strength of evidence rating. For most guideline statements, decisions as to ranking and strength were unanimous among panel members in attendance.

As part of the AHCPR process of guideline development, the panel held a public meeting and received oral and written testimony from seven participants. Additionally, the Guideline Technical Report, the Clinical Practice Guideline, and the Quick Reference Guide were all extensively reviewed by panel members and consultants and by outside reviewers of different backgrounds from both the private and public sectors. The guideline documents were revised on the basis of peer review comments.

Research Needs

The panel's review of the medical literature on mammography and breast imaging identified numerous priority areas for further research (detailed in the Guideline Technical Report), including:

• Efficacy and quality of clinical breast examinations.

• Improvement of positioning and breast compression techniques, x-ray equipment, and image receptor systems.

• Improvement of quality control and quality assurance methods.

• Improvement of communication with women and patients.

• Efficacy of mobile mammography and other methods of delivering mammography services to women in remote locations.

• Evaluation of methods of increasing mammography use by women in groups that are high risk, underserved, older, or members of ethnic subpopulations, as well as increasing use among lesbians.

• Efficacy of standardized and automated mammography reporting and recordkeeping.

• Improvement of data collection and analysis for medical audit; evaluation of the cost-effectiveness of a national mammography data base.

• Development of valid measures other than breast cancer mortality to assess the efficacy of mammography.

• Clinical trials to assess the efficacy of mammography, clinical breast examination, and breast self-examination in premenopausal women.

• Efficacy of other breast imaging modalities (digital mammography, magnetic resonance imaging, ultrasonography) in detecting breast cancer.

Future Revision of Guideline

Mammography technology changes rapidly; although screen-film mammography is the standard today, it is likely that breast imaging by digital mammography will be in clinical use in the future. Other imaging modalities and new diagnostic techniques may change clinical practice in the diagnosis of breast abnormalities and the management of patients. The Quality Determinants of Mammography Panel encourages readers of this guideline to send their comments and suggestions for revisions to the

• Director,

• Office of the Forum for Quality and Effectiveness in Health Care, Agency for Health Care Policy and Research,

• Willco Building, Suite 310, 6000 Executive Boulevard, Rockville, MD 20852.

Responsibilities of Facility Schedulers and Receptionists

The functions of scheduling the mammography examination and greeting the woman when she comes to the facility may be done by one person or different persons. Schedulers plan the details or arrangements for the mammography examination prior to the woman's arrival at the facility. Receptionists greet the woman when she arrives for her examination and obtain personal identification information.

Screening mammography is an x-ray examination used to detect unsuspected breast cancer at an early stage in asymptomatic women. Mammography may be designated as screening if the woman is scheduling a routine examination, if she has no abnormal findings on physical examination, or if she has had a previous benign biopsy. Women who have had a mastectomy should have screening mammography of the remaining breast.

Diagnostic mammography is an x-ray examination used to evaluate a woman or man with a breast mass or masses; other breast signs or symptoms (skin changes or spontaneous nipple discharge); an abnormal or equivocal screening mammogram; or special cases such as a history of breast cancer with breast conservation or augmented breasts. People receiving diagnostic mammography are termed "patients."

Figure 1. Example of a mammography scheduling (more...)

    Figure 1. Example of a mammography scheduling questionnaire

Figure 1

Obtaining information regarding cyclical breast pain is important because it permits the scheduling of screening mammography at the time most comfortable for women. Breast pain may be associated with the menstrual cycle in 40 percent of women (Preece, Hughes, Mansel et al., 1976; Stomper, Kopans, Sadowsky et al.,. 1988) It is advisable to avoid screening mammography the week before menstruation (for those women who have breast pain associated with menses) or at other times when the breasts are tender (Brew, Billings, and Chisholm, 1989; Jackson, Lex, and Smith, 1988; Stomper, Kopans, Sadowsky et al., 1988).

Accurate recording of patients' and providers' names, addresses, and phone numbers is important to ensure appropriate notification for followup of both routine and abnormal mammography results. Information from referring providers should confirm the need for screening or diagnostic mammography as well as describe any symptoms or abnormal findings. A signed referral form from the health care provider indicates that the provider will be receiving the mammography report and following the woman. A referral form that describes the location of a clinical abnormality noted by the health care provider is helpful in correlating the area of clinical concern with mammographic findings and in directing the need for and type of additional views.

Women may access mammography through multiple channels. A woman may be referred by her health care provider, she may come on her own initiative but be able to name a personal health care provider (self-requesting), or she may come on her own initiative but have no personal health care provider (self-referred). Personnel should determine each woman's entry status. If the woman has a health care provider, the personnel should obtain the provider's name, address, and phone number. If the provider does not know that the woman is scheduling a mammogram, the scheduler may call the provider's office to confirm that the woman is the provider's patient. If the woman is self-referred, this should be noted in her file.

Receiving accurate information about mammography will decrease women's anxiety and will enhance the quality of the examination. Schedulers should advise women about the approximate length of the visit and suggest that they wear a two-piece garment and not wear deodorant or cosmetics on or near the breast. The images of these substances may appear on the mammogram, compromising quality (Barton and Kornguth, 1990). Schedulers should ask about obtaining other mammography films for comparison.

Figure 1

Figure 2. Example of a mammography clinical (more...)

    Figure 2. Example of a mammography clinical history form

Figure 2

Figure 3. Example of a patient information (more...)

    Figure 3. Example of a patient information form

Figure 3

Responsibilities of Facility

As of October 1, 1994, the Mammography Quality Standards Act (MQSA) requires that mammography facilities be certified by the Food and Drug Administration (FDA). Certification requires being accredited by an FDA-approved accreditation body and meeting additional quality standards that are verified by site inspections performed by qualified MQSA inspectors. Veterans Health Administration facilities have their own mammography quality program that parallels MQSA and do not require FDA certification.

Responsibilities of Women

A woman seeking information about a mammography facility should ask whether the facility is certified by FDA (unless it is a Veterans Health Administration facility). If the answer is no, the woman should seek mammography at a certified facility.

Women should be aware of their responsibility to make followup appointments with their health care provider or a provider designated by the mammography facility.

Communication Responsibilities of Radiologic Technologists

In addition to performing mammography in a technically proficient manner, radiologic technologists can contribute to a positive experience for those being examined.

Radiologic technologists should:

• Greet the woman pleasantly, making eye contact, listening to and responding to her questions, and informing her clearly and briefly, in understandable language, about what to expect during the examination.

• Be sensitive to the woman's apprehensions and to cultural and ethnic diversity.

• Respect the woman's privacy by supplying a gown and giving instructions on how to wear it, reentering the dressing area only after knocking and asking her permission, and closing the door on entering and exiting the examination room. (Whenever possible, the woman should not be required to travel to or wait in a public area while she is in her gown.)

• Recognize that the woman may be sensitive about breast size and shape and any other conditions, including breast implants.

• Maintain a dialog with the woman, inquiring about her comfort, reassuring her, and answering questions.

• Assure the woman that the technical aspects of the mammogram will be recorded as part of her permanent record.

• Respond to questions about mammography, its radiation dose, and its role in detecting breast abnormalities.

• Be aware that the breast cancer survivor receiving her mammogram is an experienced and well-informed woman. Although her anxiety levels may be higher than those of the average woman being screened, her information needs may be different.

• Recognize that some women need counseling and support that go beyond the scope of practice of the radiologic technologist. In these instances, the radiologic technologist should refer the woman to the interpreting physician or to her health care provider.

• Not pass on their own impressions of the results of the mammography examination.

Anxiety in women being screened produces physical tension that can make the examination less comfortable (Gram and Slenker, 1992). Women may be concerned that their privacy will be compromised; that the examination will be painful; and that the examination will show or confirm an abnormality, requiring further diagnostic examination, biopsy, or treatment. Women with a family history of breast cancer or women with a prior diagnosis of breast cancer may be understandably concerned that the likelihood of an abnormal finding is greater for them than for the general population.

A woman should leave the mammography facility satisfied that all her questions about the procedure have been answered by the radiologic technologist or interpreting physician.

Figure 2

• Current breast complaint, if any (describe briefly).

• Previous mammograms (date, location, and address of mammography facility).

• Family history of breast cancer (mother, sister, or daughter; age at diagnosis; whether premenopausal or postmenopausal).

• History of breast cancer and age at diagnosis.

• Prior breast surgery.

• Date of last menstrual period (note if no longer menstruating).

Although not required for the physician interpreting the mammogram, the following information may be important for determining women's risk of breast cancer:

• Ethnic background.

• Age when menstrual period began.

• Age at first childbirth.

• Use of birth control pills and at what age.

• Age at menopause.

• Use of estrogen replacement therapy.

• History of cancer.

Although breast pain is a relatively uncommon presentation of breast cancer, its presence does not exclude the diagnosis. Several studies emphasize that when localized pain is associated with a diagnosis of breast cancer, a breast mass can usually be palpated (Haagensen, 1986; Preece, Baum, Mansel et al., 1982; Preece, Hughes, Mansel et al., 1976; River, Silverstein, Grout et al., 1951; Smallwood, Kye, and Taylor, 1986; Yorkshire Breast Cancer Group, 1983). However, women who present for mammography have not always had a clinical breast examination. Because women with localized breast pain may be unaware that they have a breast mass, some mammography practices may use the symptom of localized breast pain to determine the appropriateness of screening or diagnostic mammography.

Such materials may be offered at the mammography facility or women may be given references to educational resources such as those produced by the American Cancer Society and the National Cancer Institute.

Breast Compression

Properly applied breast compression is one of the most important factors in producing a quality image. Radiologic technologists should be able to evaluate whether the compression device is adequate and functioning properly. Breast compression evens out the thickness of the breast, allowing both thick posterior tissues and thin superficial tissues to be imaged on a single film; permits even penetration of dense fibroglandular tissues; separates breast tissues that might otherwise obscure an underlying lesion; brings objects closer to the film, reducing geometric blur; holds the breast still, preventing motion blur; decreases scatter radiation, improving contrast; and decreases radiation dose (Barnes and Brezovich, 1978; Haus, 1987). Appropriate compression makes the skin of the breast taut but does not cause pain (Eklund and Cardenosa, 1992; Hendrick, Bassett, Dodd et al., 1992).

Most women tolerate compression well and would not defer future mammography examinations because of pain (Brew, Billings, and Chisholm, 1989; Jackson, Lex, and Smith, 1988; Stomper, Kopans, Sadowsky et al., 1988). Because the leading factor predisposing to pain is the expectation of pain (Rutter, Calnan, Vaile et al., 1992), educating women about compression is essential.

A properly designed compression device is necessary to achieve adequate compression (Hendrick, Bassett, Dodd et al., 1992). The compression device should match the size of the image receptor and remain parallel to the image receptor during compression. The device should be straight at the posterior edge, to match the straight posterior edge of the film. The angle from the inferior to posterior surfaces should be 90 degrees to prevent posterior tissues from slipping out and to ensure adequate compression of the thicker posterior tissues. The chest wall edge of the compression device should be high enough to prevent chest wall structures from being superimposed on the image of the breast.

The amount of force applied by the compression device is sometimes displayed on the mammography unit. However, this type of display is not very helpful in determining the amount of compression to apply because women have different pain tolerances; the correct compressive force for different types, thicknesses, and sizes of breasts is not known; and the measurement displayed may not correlate with the force per unit area on the breast surface (Clark, Chambers, Faulkner et al., 1990; Sullivan, Beam, Goodman et al., 1991).

Screening and Diagnostic Views

Two-view examinations detect more cancers and produce fewer false-positive results than do one-view examinations (Andersson, 1981; Anttinen, Pamilo, Roiha et al., 1989; Bassett, Bunnell, Jahanshahi et al., 1987; Ikeda and Sickles, 1988; Muir, Kirkpatrick, Roberts et al., 1984; Sickles, Weber, Galvin et al., 1986). Two-view screening is likely to be less expensive and to cause women less anxiety, because fewer women need to be called back for additional views (Bassett, Bunnell, Jahanshahi et al., 1987; Sickles, Weber, Galvin et al., 1986).

Figure 4. Correct positioning for the mediolateral (more...)

    Figure 4. Correct positioning for the mediolateral oblique (MLO) view

Figure 5. Correct positioning for the craniocaudal (more...)

    Figure 5. Correct positioning for the craniocaudal (CC) view

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Table 1. Diagnostic views for mammography

Table 1. Diagnostic views for mammography

Projection/view (abbreviation)	Indications	How it provides higher quality images and how the information improves interpretation and patient management
Spot compression (Can be done in any of the projections below)	To confirm an abnormality is real. To better define a lesion obscured by overlying tissue.	Separates tissues overlying and obscuring an area of interest; provides increase in local compression (bringing object closer to film). Eliminates the need for biopsy if lesion is shown to be factitious. Can confirm need for biopsy.
Magnification (M) (Can be done in any of the projections below)	To better define calcifications and margins of masses.	Improved definition of abnormality will help determine whether it is suspicious and requires biopsy or whether it is probably benign and can be followed.
90degrees lateral (ML, LM)	To localize an abnormality (in conjunction with CC). To confirm presence of a lesion seen on only one standard view. To demonstrate gravity-dependent material (milk-of-calcium).	Provides view directly at right angles to CC, allowing 3-dimensional localization so that mammographic finding can be correlated with clinical breast examination and, if nonpalpable, can be removed by needle localization, resulting in minimal biopsy scar. As a third view, can confirm whether lesion is real or factitious. If calcifications are shown to be gravity dependent, they represent benign "milk-of-calcium" and a biopsy can be avoided.
Exaggerated craniocaudal (XCCL)	To localize an abnormality seen on MLO but not CC and expected to be in the posterolateral part of the breast or axillary tail. May be needed to image the lateral-most portion of the breast in some women with prominent axillary tissue.	Images posterolateral breast tissue, which is not always demonstrated with standard CC positioning. Allows localization of lesions in outer breast for correlative examination and, if suspicious, for needle localization.
Cleavage (CV)	To localize an abnormality seen on MLO but not CC and expected to be in the deep medial breast.	Images posteromedial breast tissue, which may not be seen with standard CC positioning, allowing for correlative examination or needle localization.
Axillary tail (AT)	To localize an abnormality high in the tail of Spence and not seen on standard views.	Images axillary tail of breast tissue.
Tangential (TAN)	To depict a palpable lesion that is obscured by overlying dense tissue. To verify the dermal location of calcifications or skin lesions.	By placing a palpable lesion that is obscured by overlying tissue directly over radiolucent subcutaneous fat, the lesion may be seen so that it can be characterized as benign or suspicious. By directing the beam tangential to skin calcifications, a suspected dermal location can be confirmed and unnecessary biopsy avoided.
Roll (RL, RM)	To bring a lesion that is obscured by overlying tissue into view. To estimate the location of a lesion seen in only one view by observing how it moves on roll views.	By rolling the breast, the relationship between a lesion and overlying tissues will be changed and the lesion may be better visualized. The direction the lesion moves may help in determining its location. It may be useful in better defining or localizing a lesion seen on only one view.
Caudocranial (FB) (from below)	To better define the nature of a mass in the upper part of the breast or include more of it on the image. To improve positioning of some patients with problematic body habitus. May also be used for preoperative needle localizations of lesions near the inferior skin surface.	Because an abnormality high in the breast will be closer to the film on the FB, it can be better defined. Because the compression plate will be moving against movable rather than fixed tissue, more of the deep superior tissues can be included on the image.
Lateromedial oblique (LMO)	To improve positioning of some patients with problematic body habitus (kyphosis) and pacemakers. To better depict lesions in the superomedial part of the breast.	By reversing the location of compression device and Bucky, more tissue can be included and better compression achieved in some patients. Lesions in the superomedial aspect of the breast will be closer to the film.
Superolateral to inferomedial oblique (SIO)	For needle localization of lesions seen in AT view but not CC.	Can be done at 90degrees to AT view, allowing needle localization and wire placement for abnormalities that are seen on AT view but not on CC or XCCL views.
Implant displacement (ID)	To better image patients with augmentation mammoplasties.	By displacing the implant posteriorly and pulling tissue anteriorly away from the implant, more compression can be applied to improve visualization of tissues.
Imaging mastectomy site	To identify recurrent breast cancer at chest wall.	It is controversial whether this is an effective procedure. Most recurrences at the chest wall are clinically detected. When performed, a mediolateral oblique projection of the mastectomy site or an axillary view is done.
Conservatively treated breast: preradiotherapy magnification views over site of segmental resection	To identify residual tumor at the surgical site, particularly calcifications of nonpalpable intraductal cancer.	Identifying residual tumor and removing it before radiotherapy may decrease incidence of recurrent breast cancer at the surgical site.
Conservatively treated breast: postradiotherapy magnification views over site of segmental resection	Performed at regular intervals to identify recurrent cancer.	By placing a wire directly over the surgical site and using magnification films at regular intervals, it may be possible to identify changes of recurrent cancer as early as possible.
Specimen radiography	To verify that a nonpalpable lesion is present in a biopsy specimen from a mammographically guided localization procedure. Locates abnormality for the pathologist's attention on the area of concern (the area requiring detailed histological evaluation).	Verification of the presence of the lesion on the specimen radiograph ensures that the suspicious finding has been removed for pathologic evaluation. If the lesion is not present in the first specimen radiograph, additional tissue will be excised and radiographed.

Note: CC = craniocaudal. MLO = mediolateral oblique.

Positioning Techniques

Approaches to breast positioning have changed significantly in recent years (Eklund and Cardenosa, 1992; Hendrick, Bassett, Dodd et al., 1992). Inadequate positioning, causing suboptimal clinical images, is the most common reason for mammography facilities failing the American College of Radiology Mammography Accreditation Program (Hendrick, 1992). Dedicated equipment permits breast positioning according to the woman's specific habitus or breast problem.

The first step in positioning the breast is to select the proper image receptor size for the woman's breast. Currently image receptors come in two sizes, 18 cm x 24 cm and 24 cm x 30 cm. Using the smaller image receptor system for a larger breast results in omission of breast tissue from the image. Conversely, using the larger image receptor for small breasts prevents adequate breast compression and positioning and may also result in other body parts being superimposed on the image. The moving grid and compression device that are used should be the appropriate size for the image receptor.

Table 2. Mammography positioning techniques

Table 2. Mammography positioning techniques

View/projection (abbreviation)	Purpose	Positioning techniques for technologist: (step-by-step)
Craniocaudal (CC)	Standard view	Goal is to depict all of the medial tissue and as much lateral tissue as possible. Lift inframammary fold as high as natural mobility will allow. Raise cassette holder to level of elevated inframammary fold. Use 2 hands (1 below, 1 above) to pull breast onto Bucky. Use 1 hand to hold this position; bring patient's head forward. Drape breast not being imaged over corner of Bucky. Instruct patient to place contralateral arm on handlebar. Place arm around patient's shoulder to "relax" other shoulder. Use same hand to slide skin over clavicle. Pull additional lateral tissue onto the Bucky without displacing any medial tissue. Move hand holding breast toward nipple during compression. Smooth lateral tissue anteriorly to remove skinfolds.
Mediolateral oblique (MLO)	Standard view	Rotate C-arm so that Bucky is parallel to pectoral muscle. Patient's hand on side being imaged is relaxed holding handlebar. Bring patient toward Bucky so edge of Bucky fits high in axilla. Bucky is under pectoralis but in front of latissimus dorsi. Arm is in relaxed position, with elbow flexed behind Bucky. With hand, lift breast and pectoralis muscle anteriorly and medially. Rotate patient toward the Bucky; edge of cassette replaces hand in supporting breast. Use hand to hold breast up and out, away from chest wall, to prevent overlapping of tissue. Begin to apply compression with upper corner of compression paddle just below the clavicle. Move hand toward nipple as compression is holding up the breast: first the thick posterior tissues, then thin anterior. This is called the "up-and-out" maneuver. Pull abdominal tissue down to open inframammary fold.
90degrees lateral (LM)	Localize an abnormality. Demonstrate gravity-dependent material (milk-of-calcium). Improve visualization of lesions in the medial breast due to reduced object-to-film distance.	Tube arm is rotated 90degrees, with top Bucky at suprasternal notch. Patient positioned with sternum against edge of Bucky, neck extended, chin resting on top of Bucky. Ipsilateral arm is lifted over Bucky. Elbow is flexed to relax pectoralis muscle. Pull mobile lateral and inferior tissue up and toward midline. Rotate patient toward cassette holder. Bring compression paddle down past latissimus dorsi. Rotate until breast is in true lateral position, centered on Bucky. Open inframammary fold, gently pulling abdominal tissue down.
Spot compression	Better define a lesion by displacing overlying parenchymal tissue and improving compression. Determine whether lesion is real. Combined with magnification radiography to improve visualization of calcifications or margins of masses.	Using original mammograms, the technologist determines the placement of the small compression device by measuring the distance of the abnormality from the nipple. A pen can be used to mark the estimated location of the lesion on the overlying skin. This will expedite repositioning if the film shows that the lesion was not included in the field. Collimation: Whether to use a smaller or larger field will depend on the individual case. When attempting to determine whether a lesion is real, a larger field would be desired in order to be sure the area is included. When inspecting the margins of a definite mass, a smaller field provides improved contrast.
Exaggerated craniocaudal (XCCL)	Depict posterior lesions of outer aspect of the breast, axillary tail.	Begin positioning as for the routine CC. After elevating the inframammary fold, rotate the patient until the lateral aspect of the breast is positioned on the Bucky. If the shoulder is in the way of the compression paddle, a 5degree lateral tube angle can be used to allow the compression paddle to clear the humeral head.
Cleavage (CV)	Also called "valley view" or double-breast compression view. Performed to visualize deep lesions in the posteromedial aspect of the breast.	The patient's head is turned away from the side of interest. Can be done with the technologist standing behind the patient and wrapping her arms around the patient to reach her breasts or with the technologist standing in front of the patient on the medial side of the breast being imaged. Either way, the technologist must be sure to elevate inframammary folds and position both breasts on the cassette holder. Pull all of the medial tissue of both breasts anteriorly in order to image the cleavage. Manual technique should be used when photocell is directly under cleavage. Automatic exposure control can be used if the breast of interest is over the photocell—with cleavage slightly off-centered.
Axillary tail (AT)	Sometimes incorrectly called "Cleopatra" view. Demonstrate entire axillary tail as well as most of lateral aspect of breast.	Tube arm is rotated to an angle that will place Bucky parallel to axillary tail. Patient is turned to bring the axillary tail in contact with Bucky. Patient's arm on the side being imaged is draped behind top of Bucky, with the elbow flexed and the hand resting on handlebar. Gently pull axillary aspect of the breast out and away from chest wall and place it on the Bucky. Hold the axillary tail in place with hand while slowly applying compression.
Tangential (TAN)	Show palpable lesions obscured by overlying dense fibroglandular tissue. Verify that calcifications seen on a mammogram are within the skin.	For palpable lump: Rotate tube and breast until lump is tangential to x-ray beam. This may show lump over radiolucent subcutaneous fat. For skin calcifications: Using alphanumeric grid or hole-plate for guidance, place radiopaque marker (BB) on skin directly over calcifications. Be sure marker is on correct side of breast (e.g., superior vs. inferior). Rotate tube and breast until BB is tangential to x-ray beam. Film should show dermal calcifications in skin.
Roll view (RL, RM)	Separates superimposed breast tissues to confirm the presence of an abnormality, better define a lesion, or determine the location of a finding seen on only one standard view.	The patient is repositioned using the same projection that demonstrated the abnormality. With hands placed on either side of the breast, the technologist "rolls" the tissue in opposite directions. Compression will maintain the breast in the "rolled" position. The direction of the roll (lateral or medial) should be written on the film.
Caudocranial (FB)	Improve visualization of lesions in superior breast due to reduced object-to-film distance. Include more posterosuperior tissue. For prebiopsy localization, provides shorter route to inferior lesion. Improve amount of tissue shown for male breasts and woman with kyphosis.	The tube arm is rotated 180 degrees. The patient will face the unit with one leg on either side of the tube head. The inframammary fold is elevated, and then the height of the tube arm is adjusted so that the superior border of the breast will be in contact with the Bucky. With one hand on top of the breast and the other hand under the breast, the technologist gently pulls the tissue away from the chest wall and centers the breast on the Bucky. Compression is applied slowly.
Lateromedial oblique (LMO)	"Reverse oblique." Improve visualization of medial breast tissue due to reduced object-to-film distance. More comfortably position breast, and include more tissue, in woman with pectus excavatum, woman who has had recent open heart surgery, or woman with a prominent pacemaker.	X-ray beam directed from the lower-outer to the upper-inner -- exact reverse of MLO. As for MLO, Bucky is parallel to the plane of pectoral muscle, optimizing amount of breast tissue that is depicted. Tube arm is rotated to appropriate angle with beam at an inferolateral to superomedial direction. Height of Bucky is adjusted so breast is centered. Patient should lean forward to place the edge of the Bucky against the sternum. Patient's arm will be draped over the top of the Bucky, with elbow flexed. The technologist gently pulls the breast up and out from the chest wall, making sure all medial tissue is in front of the Bucky. Begin to rotate the patient toward the film. Bring the compression device down beyond the latissimus dorsi, then finish rotating the patient forward until all breast tissue is centered on film. After breast is fully compressed, the inframammary fold is opened by gently pulling abdominal tissue down.
Superolateral to inferomedial oblique (SIO)	Limited usefulness. Can be used as orthogonal view to AT for wire localization of lesion in axillary tail.	This oblique view is performed with the central ray directed upper-outer to lower-inner. The maneuvers used for the MLO are adjusted for the different projection of the beam.
Implant displaced (ID)	Improved imaging of the augmented breast. Greatly improves visibility of breast tissue.	Routine CC and MLO views require manually set exposure factors, and amount of compression is limited by compressibility of the implant. Women with augmented breasts should have CC-ID and MLO-ID views if possible. In ID views, prosthesis is displaced posteriorly and superiorly against chest wall while breast tissue is gently pulled anteriorly to prosthesis onto the image receptor and held in place with the compression device. For CC view, the tissue superior and inferior to the prosthesis will be pulled forward, as well as all the anterior tissue. For an MLO, the tissue superomedial and inferolateral will be pulled forward with the anterior tissue.
Mastectomy site	Imaging the postmastectomy side is controversial.	Those who recommend this procedure might include an MLO projection of the skin over the mastectomy site, a spot view of any area of concern, and an anteroposterior view of the axilla.
Imaging the conservatively treated breast	Identify residual cancer postlumpectomy/ preradiotherapy and early detection of recurrent cancer.	MLO and CC views of the whole breast are performed. In addition, when malignant calcifications have been removed, spot compression magnification views over the biopsy scar facilitate the identification of residual calcifications.
Specimen radiography	Verify that a nonpalpable lesion has been removed after wire localization/ excisional biopsy.	Can be performed on dedicated mammography unit or compact specimen radiography unit. Low kVp technique is used (e.g., 22 kVp for dedicated unit, 18 kVp for specimen unit). Magnification is recommended, especially for calcifications. Other techniques may improve specimen radiography: compression of the specimen and turning the specimen and exposing an orthogonal projection when the lesion is not seen on the first specimen radiograph.

Specimen radiography is necessary to verify that a suspicious nonpalpable abnormality has been removed after mammographically guided needle localization and excisional biopsy (Chilcote, Davis, Suchy et al., 1988; Rebner, Pennes, Baker et al., 1989).

Technique Factor Selection

The goal of kVp selection is to maximize contrast in the fibroglandular tissue of the breast. Data support the correlation between low kVp and improved contrast in breast tissue (Law, 1992). Balance needs to be maintained between low kVp and exposure time (less than 2 seconds) to minimize motion blur. Documented kVp, target material, filtration material, and exposure time (or mAs) as well as film optical density and image contrast can be useful in improving subsequent mammograms.

The AEC technique chart should specify user technique selections (anode material, filter material, kVp, and density control setting adjustments) to maintain appropriate and consistent film density as a function of compressed breast thickness and tissue density (Karila, 1982a; Niklason, Barnes, and Rubin, 1985). The manual technique chart should be used for special circumstances, such as implants, irradiated breasts, axillary views, and cleavage views, and if the AEC is malfunctioning.

Obtaining the appropriate optical density in the area of interest is a prerequisite to adequate image contrast. Technologists cannot adequately predict tissue density through physical assessment (Swann, Kopans, McCarthy et al., 1987). The use of AEC and the inspection of previous films is essential to produce images of consistent, appropriate density.

Grids improve subject contrast by reducing the amount of scattered radiation reaching the image receptor (Dance, Persliden, and Carlsson, 1992; Sickles and Weber, 1986). Scattered radiation values are greatest for thicker breasts. Ample evidence supports the use of grids for imaging thick, dense breasts (Dance, Persliden, and Carlsson, 1992; Dershaw, Masterson, Malik et al., 1985). Because radiologic technologists cannot accurately predict the compressibility and density of the breast from physical examination (Swann, Kopans, McCarthy et al., 1987) and because of panel expert opinion, the panel recommends the use of grids for contact mammography for all breasts.

Communicating Results

Table 3. Reporting the results by mammography facility (more...)

Table 3. Reporting the results by mammography facility

	Communication to women
Outcome of mammography examination and recommendation for followup	Oral (on site or by telephone)	Written (on site or sent by mail	Phone communication to health care provider in addition to standard report	Always necessary: written report to health care provider
Normal	Optional	Strongly recommended	None	Strongly recommended
Abnormal: schedule additional imaging and/or ultrasonography
(a) On line [1]	Recommended [2]	Strongly recommended [2]	Recommended [3]	Strongly recommended
(b) Off line [1]	Optional [2]	Strongly recommended [2]	Recommended [3]	Strongly recommended
Abnormal: short-interval followup	Optional	Strongly recommended	Optional	Strongly recommended
Abnormal: biopsy	Optional, strongly recommended for self-referred women	Strongly recommended [4]	Strongly recommended	Strongly recommended

[1] For an online study, the interpreting physician is present and reads the mammogram while the patient is there. For an offline study, the mammogram may be read after the woman leaves so the interpreting physician does not need to be present.

[2] For any patient for whom additional views or ultrasonography are recommended, a telephone call or discussion onsite with the patient may precede the written letter when the studies are to be performed immediately or within 2 days at that mammography facility. However, the results of the original and additional studies must be provided to the woman in writing.

[3] A telephone call from the mammography facility to the woman's designated physician or other health care provider is recommended. For self-referred patients, the telephone call should be made to the woman herself.

[4] For any patient without a direct referral, the mammography facility may wish to send the letter via registered or certified mail.

Note: Strong recommendations deal with elements of mammography that the panel considers essential to good practice. Recommendations deal with elements of mammography that the panel considers attainable in most but not all cases. Options are statements of a less compelling nature that cannot be justified as recommendations.

An increasing number of mammography facilities have begun to report both normal and abnormal results directly to the woman. This can be accomplished without disrupting the woman's relationship with her referring provider. Studies have shown that direct communication of results to the woman by the mammography facility produces a dramatic improvement in compliance with followup recommendations (Cardenosa and Eklund, 1991; Monsees, Destouet, and Evens, 1988; Rubin, Frank, Stanley et al., 1990). To be most effective, results should be presented clearly and promptly (Aalders and Schade, 1991; Bird and McLelland, 1986; Dershaw, Liberman, and Lippin, 1992; Kessler, Rimer, Devine et al., 1991; Monsees, Destouet, and Evens, 1988; Rubin, Frank, Stanley et al., 1990). Traditional communication procedures, where the facility communicates only with the referring provider, result in inadequate compliance with followup recommendations (Robertson and Kopans, 1989).

Communicating normal results directly to the woman as soon as possible eliminates anxiety, reinforces the woman's role as a responsible participant in the process, reminds the woman of the importance of regular screening, and is a quality assurance safeguard. Effective communication is most crucial when results are abnormal and additional imaging or other followup is required. If findings are abnormal, the written results should detail steps the woman should take next.

Problems in communicating abnormal results have included confusion concerning the appropriate steps to be taken; inappropriate or insensitive communication, resulting in avoidable anxiety and confusion; delay in receipt of results; and failure to communicate results to the woman at all-for example, when reports are misfiled or filed unread. These problems have caused delays in diagnosis and treatment, with consequences that include limited treatment options and death (Brenner, 1992a and 1992b; De Neef and Gandara, 1991; Robertson and Kopans, 1989; Unger, 1990). Providing results directly to the woman is a sound risk-management procedure, reducing the prospect of medicolegal complications for both the interpreting physician and the referring health care provider (Rubin, Frank, Stanley et al., 1990.)/P>

Any written communication must have language that is carefully constructed to impart results without causing undue anxiety, to promote a relationship between the woman and a health care provider, and to encourage the woman to take the next step. Examples of letters communicating results directly to women are shown on the following pages. These are only examples. They should be adapted to local populations in a manner that is sensitive to cultural diversity and to prearranged protocols between the mammography facility and the referring provider. Examples of communication of normal results are shown in a short form in Sample Letter A and in a longer version in Sample Letters B (for a screening mammogram) and C (for a diagnostic mammogram). Examples of communication of an abnormal result with a recommendation for short-interval followup are shown in a brief form in Sample Letter D and a longer version in Sample Letter E. Examples of notification to women of abnormal results with a recommendation for additional imaging or biopsy are shown in brief form in Sample Letter D and in longer form in Sample Letters F and G.

Mammography facilities may accept self-requesting and self-referred women for mammography. Interpreting physicians have additional responsibilities for ensuring the effective communication of results for these women.

• Self-requesting woman. This woman comes for mammography on her own initiative but is able to name a personal physician or health care provider. Whether the woman is having screening or diagnostic mammography, the interpreting physician should document that the designated provider accepts responsibility for the woman's breast care before sending the mammography report. In cases where the provider declines to accept the mammography report from the mammography facility, the facility should treat the woman as if she were self-referred.

• Self-referred woman. This is a woman who comes for mammography but has no personal health care provider or for whom the provider declines responsibility. Whether the woman is having screening or diagnostic mammography, the interpreting physician assumes responsibility for the woman's breast care, including education, physical examination, and communication of mammography results directly to the patient in understandable language. Mammography facility personnel should give the woman a list of qualified providers. If the woman chooses a provider from a list provided by the mammography facility, the interpreting physician should ensure that the chosen clinician will assume responsibility for the woman's breast care. Although self-referral has improved access to mammography, it has increased the responsibilities of the interpreting physician and created more possibilities for failure to communicate abnormal results.

Mammography facility personnel should telephone the referring or designated health care provider because the written report may not reach the provider or may not arrive in time for the provider to respond to questions from the patient. A telephone call also enables the provider to ask questions about the report and to discuss followup options with the interpreting physician (Brenner, 1992b; Cardenosa and Eklund, 1991; Dershaw, Liberman, and Lippin, 1992; McLelland, 1987; Monsees, Destouet, and Evens, 1988; Robertson and Kopans, 1989; Rubin, Frank, Stanley et al., 1990).

When mammography results are abnormal, a telephone call to the woman's designated health care provider before a report is sent may identify and resolve any vagueness in the provider-patient status. For a self-requesting woman with an abnormal finding, this call will significantly reduce the chance that she will slip through the cracks.

Followup, Tracking, and Monitoring

The primary concern in monitoring and tracking of women with normal results is compliance with regular screening guidelines. The responsibility for that effort should lie with the woman's health care provider, who interacts regularly with the woman and can inform her of the schedule appropriate for her. Ultimately, the responsibility for compliance with screening guidelines lies with the woman herself (Aalders and Schade, 1991).

For referred and self-requesting women, this reminder may be communicated by the referring health care provider rather than by the mammography facility, according to prearranged protocols. If a woman does not have a health care provider, the mammography facility is responsible for monitoring and tracking.

Both written reminders (personal letter or postcard) to the woman and facilitated scheduling during an office visit increase use of screening mammography (Chambers, Balaban, Carlson et al., 1989; Hurley, Jolley, Livingston et al., 1992; Nattinger, Panzer, and Janus, 1989; Wolosin, 1990). Computerized patient records that prompt physician compliance with screening recommendations also have a positive effect on patient referral to mammography (Harris, O'Malley, Fletcher et al., 1990; McDonald, Hui, Smith et al., 1984; McPhee, Bird, Fordham et al., 1991). Computerized patient records and computer-generated letters offer efficiencies in many practice settings (Gann, Melville, and Luckman, 1993; Haug, Tocino, Clayton et al., 1987; Payton, 1991). Other approaches may be needed to increase the use of screening mammography by low-income and non-English-speaking patient populations (Coll, O'Connor, Crabtree et al., 1990; Lacey, Phillips, Ansell et al., 1989; Lane, Polednak, and Burg, 1992; Lovejoy, Jenkins, Wu et al., 1989; Stein and Fox, 1990; Vernon, Vogel, Halabi et al., 1992).

For women without a health care provider, the mammography facility that performed the initial mammography examination should be responsible for performing or arranging for the future examination or the immediate additional views and/or procedures to be performed. This should be followed by onsite consultation with the woman or prompt communication by mail to report the results and recommended next steps. The woman herself is responsible for complying with followup recommendations. However, it is important that she receive written results and recommendations in lay language using culturally relevant terms.

When the health care provider named by the woman does not accept the report, the mammography facility should treat the woman as if she does not have a provider and should assist her in identifying a provider who will accept her as a patient and to whom all reports should be sent. Important issues to the patient in identifying a provider are location, hours of operation, transportation, cost, and acceptance of insurance, Medicaid, or Medicare.

A recommendation that biopsy be considered introduces the involvement of other medical specialists and additional considerations that are best evaluated, discussed, and decided upon by the patient and her health care provider, with the interpreting physician providing consultative support. Decisions about referrals to appropriate medical personnel, such as a surgeon, should be made by the woman in consultation with her provider.

The mammography facility should maintain a tracking system to monitor patient compliance with recommendations for biopsy. Compliance may be monitored through direct communication with the woman's referring or designated health care provider.

The interpreting physician and other mammography facility personnel should continue to be available to the woman and her provider to discuss the interpretation of abnormal findings. Both the woman's provider and the mammography facility should implement tracking systems, which have been shown to improve patient compliance with followup recommendations (Aalders and Schade, 1991; Chambers, Balaban, Carlson et al., 1989; Elsenhans, 1991; Haug, Tocino, Clayton et al., 1987; Monticciolo and Sickles, 1990; Robertson and Kopans, 1989).

The performance of additional mammographic views is not considered a medical emergency. Nonetheless, additional views and adjunctive diagnostic procedures should be done as soon as possible-at least within 1 month.

Facilities that have only screening services provide an important and cost-efficient service to asymptomatic women, most of whom do not need additional diagnostic imaging. However, quality care is facilitated by immediate, onsite performance of additional studies made necessary by an abnormal screening mammogram. Assistance with scheduling necessary additional studies facilitates the highest compliance with followup of breast imaging recommendations (Cardenosa and Eklund, 1991; Monsees, Destouet, and Evens, 1988; Rubin, Frank, Stanley et al., 1990).

There are some reports that Medicare regulations (Department of Health and Human Services, 1990) may be interpreted to prevent immediate diagnostic followup of an abnormal screening mammogram, especially in cases where the woman is self-referred or self-requesting. However, this interpretation of Medicare regulations is not correct. Medicare covers immediate diagnostic followup of problems identified in a screening mammogram. The panel recommends that the Health Care Financing Administration regional or central offices be notified about any problems identified in this regard. Interpreting physicians should document that a finding present on the screening examination required additional imaging before a diagnosis could be made.

Mammography Report

Breast composition may be described as (1) almost entirely fat; (2) there are scattered fibroglandular densities that could obscure a lesion on mammography; (3) breast tissue is heterogeneously dense, which may lower the sensitivity of mammography; (4) breast tissue is extremely dense, which lowers the sensitivity of mammography. An implant code should be added if an implant is present. Description of findings should use standardized terminology:

• Masses-describe:

• Shape

• Margin characteristics

• Density

• Location (clock face)

• Size

• Calcification-describe:

  • Element morphology

  • Distribution

  • Location (clock face)

• Other-describe:

  • Architectural distortion

  • Asymmetry

  • Skin and/or nipple retraction

  • Skin and/or trabecular thickening

A concise and understandable report increases the use of screening and diagnostic mammography (Hindle, 1991). The American College of Radiology (ACR) has developed a Breast Imaging Reporting and Data System (BI-RADS[trademark]) containing standardized terminology and recommendations (Kopans, 1992a; Kopans and D'Orsi, 1992; Kopans, D'Orsi, Adler et al., 1993). Using this terminology, three experienced interpreting physicians produced almost identical receiver operator characteristics curves on 300 test cases (D'Orsi, Getty, Swets et al., 1992). Uniform terminology with a structured delivery should eliminate confusion in communicating results (D'Orsi and Kopans, 1993; Homer, 1984; Kopans, 1992a; Kopans and D'Orsi, 1992; Sierra, Bisesi, Rosenbaum et al., 1992).

This represents good medical practice and is universally accepted. Clinical concerns usually relate to a palpable, focal, asymmetric mass or area in the breast, nipple discharge, focal persistent pain, and nipple or skin change. Radiopaque markers such as BBs placed on focal, palpable findings or areas of localized pain may enhance further patient management. Nipple discharge or skin and/or nipple change do not require markers, but a statement in the report indicating the presence (or absence) of mammography findings that support (or do not support) the clinical impression is helpful. Ductography may be helpful in identifying intraductal lesions. If no findings are present on the mammograms when clinical findings are evident, a statement should be added urging the clinician to address these areas of clinical concern independent of mammography results.

The report should include one of the assessments and recommendations for future action listed below, as warranted:

• Needs Additional Evaluation (A)-This may take the form of additional mammographic views and/or ultrasonography or other procedure.

• Negative (N)-(Routine followup.) Nothing to comment on. If there is a clinical finding, a statement indicating that this finding should be dealt with independently of the negative mammogram should be added.

• Benign Finding (B)-(Routine followup.) Also negative, but the interpreting physician may wish to describe a typically benign finding: e.g., calcified fibroadenoma.

• Probably Benign Finding (P)-Short-interval followup suggested. A finding with a very high probability of being benign and not expected to change over the followup interval.

• Suspicious Finding (S)-Biopsy should be considered. A finding without the characteristic morphology of breast cancer but having a definite probability of being malignant.

• Highly Suggestive of Malignancy (M)-Appropriate action should be taken. These findings have a high probability of being cancer.

These assessments and recommendations are from the American College of Radiology's Breast Imaging Reporting and Data System, or BI-RADS[trademark] (Kopans, D'Orsi, Adler et al., 1993). A classification system will aid in patient management, increase use of mammography, and instill confidence in both patient and clinician. The clear description of levels of confidence for the presence of malignancy, as outlined in the assessment scales, can aid understanding of the report, enhance effective assignment of patients, and simplify long-term tracking (Kemp and Jackson, 1987; Rosenbaum, 1990; Schutte, 1985).

Results of second-opinion examinations should be treated the same as results of diagnostic examinations. A report should be sent to the health care provider and results passed on to the woman. If the results of the first report and second opinion are substantially different and will affect the woman's further care, this should also be communicated directly to the health care provider. If an oral second opinion is given to the referring health care provider, a brief note in a log documenting the interchange may be prudent. The note should include the name of the original facility, the determination, whether the impression is substantially different, and recommendations.

For any system to be useful it must be reliable and easy to use (Baron and Strange, 1990; Robbins, Vincent, Shaffer et al., 1988). A coding system will ease production of computerized reports and greatly simplify quality assurance. It will also facilitate comparison of data among interpreting physicians and help highlight areas requiring further training (American College of Radiology, 1993a; Bramble, Chang, and Martin, 1989).

Recordkeeping

This information can be collected before, during, and after the mammography examination. It should be kept in the form of a medical record for that patient. Information retention permits a better mammography audit, boosts confidence in accuracy of interpretation, increases the likelihood of compliance with recommendations for followup and/or subsequent management (Elsenhans, 1991; Monticciolo and Sickles, 1990; Sickles, 1990a and 1992), encourages women and physicians to follow guidelines for screening (Sickles, 1990b; Tocino, 1989), and encourages third-party payers to reimburse for screening mammography (Clark, King, and Worden, 1989; Haug, Tocino, Clayton et al., 1987; Laszlo, 1985).

The following data can be included:

• Patient-related data:

• Demographic (age, race, ethnicity, sex).

• Prior mammography (date, location).

• Patient's personal history (cancer risk profile-history of prior breast cancer, date, treatment; history of prior breast surgery, date, outcome, hormonal status).

• Family history relevant to breast cancer (first-degree relative; pre- or post-menopausal).

• For a diagnostic study, pertinent clinical data (complaints, symptoms, clinical breast examination results).

• Mammography and other breast imaging data:

• Whether a screening or diagnostic examination was performed.

• Which technologist performed the mammogram.

• Whether or not comparison was made with a prior study.

• For a diagnostic study, what diagnostic views or imaging procedures were performed.

• Mammography interpretation and reporting data:

• Film interpretation, report.

• For a diagnostic study, what specific attention was paid to the area or breast for which abnormal clinical breast examination results were found by the referring health care provider.

• Recommendation for further followup (if indicated).

• Documentation of reporting (including the date the report was sent or communicated): written report or recommendation to the referring health care provider; written report, letter, or recommendation to the patient; any telephone communications.

• Other data:

• Patient education offered or given.

• Date for followup or next screening examination.

• For biopsy, pathology report, surgical outcome, and staging information.

X-Ray Equipment Specifications

Image Receptor Specifications

Single-screen/single-emulsion film systems provide higher spatial resolution and appear to provide better detection of microcalcifications than do dual-screen/dual-emulsion systems for contact mammography (Kimme-Smith, Bassett, Gold et al., 1987 and 1990; Kirkpatrick and Law, 1987; Law, 1990; Law and Kirkpatrick, 1989 and 1990; Oestmann, Kopans, Linetsky et al., 1988; Schueler, Gray, and Gisvold, 1992). For magnification mammography, the loss of spatial resolution in dual-screen/ dual-emulsion image receptors is offset by the magnification of the object in the image and by the higher speed of the image receptor, which reduces exposure time and breast dose (Oestmann, Kopans, Linetsky et al., 1988).

Processor Specifications and Operating Conditions

Wide variation in processing is due to variations in chemistry, replenishment rates, development time, and developer temperature (Galkin, Feig, and Muir, 1988; Suleiman, Conway, Rueter et al., 1992). Suboptimal processing due to any of these factors results in reduced image quality or increased patient exposure (American College of Radiology, forthcoming; Galkin, Feig, and Muir, 1988; Kimme-Smith, Bassett, Gold et al., 1991; Kimme-Smith, Rothschild, Bassett et al., 1989; Law and Kirkpatrick, 1988; Skubic, Yagan, Oravec et al., 1990; Suleiman, Conway, Rueter et al., 1992). Latent image fade can contribute to increased patient dose and variability in image quality (American College of Radiology, forthcoming; Kimme-Smith, Bassett, Gold et al., 1991). Prolonged delay (greater than 10 hours) between exposure and processing is not recommended. These issues are particularly critical for mobile mammography, where onboard processing is unavailable.

Film-Viewing Equipment Specifications and Positioning

Several studies show that high levels of ambient lighting (whether from environmental sources or from light emanating from adjacent viewboxes) can reduce the level of perceived contrast (Alter, Kargas, Kargas et al., 1982; Bollen, 1981). One study indicates that viewbox luminance varies widely at mammographic facilities (Haus, Gray, and Daly, 1993).

Mammographic viewboxes should operate at a luminance higher than that used for conventional radiographic films because image contrast is maximized at higher film density levels (American College of Radiology, forthcoming). To maximize contrast, the ambient lighting in the viewing room should be minimized. Rectangular collimation of the x-ray field should be used, and the mammograms should be masked when being viewed to exclude extraneous light, which reduces the eye's contrast sensitivity. The interpreting physician should have access to a magnifying lens and bright light.

Quality Control Tests and Responsibilities

Medical Physicists

Strong Recommendation: Specified quality control tests should be conducted by a qualified medical physicist at least annually and after major equipment changes. (B)

The medical physicist should review the radiologic technologist's quality control test results at least annually. The medical physicist should present the facility with a detailed report of all measurements and a summary of test results and recommendations.

Table 4. Strongly recommended medical physicist quality (more...)

Table 4. Strongly recommended medical physicist quality control test

Quality control test	Minimum frequency	Purpose
Mammographic unit assembly evaluation	Annually	To ensure that mechanical components of the x-ray equipment are reliable and safe to patients.
Collimation assessment	Annually	To ensure that the radiation field matches the light field and image receptor to minimize unnecessary patient dose.
Focal spot size or limiting spatial resolution measurement	Annually	To ensure a sufficiently small focal spot to maintain image sharpness.
Peak kilovoltage (kVp) accuracy/reproducibility	Annually	To ensure that the indicated peak x-ray energy is accurate and reproducible so that consistent contrast is maintained.
Beam quality assessment (half-value layer measurement)	Annually	To ensure that the x-ray beam is sufficiently penetrating to minimize patient dose, but not so penetrating that contrast is reduced.
Automatic exposure control (AEC) system performance assessment	Annually	To ensure that the AEC system keeps average film densities at a consistent level to maintain consistent image contrast.
Uniformity of screen speed	Annually	To ensure that each cassette produces the same film optical density to maintain consistent image contrast.
Breast entrance exposure and average glandular dose measurement	Annually	To ensure that breast radiation doses are adequately low to protect patient and sufficient to maintain adequate image quality.
Image quality evaluation	Annually	To ensure that image quality is consistently high.
Artifact evaluation	Annually	To detect the presence of artifacts, isolate their sources, and ensure that they are eliminated or minimized.

Several studies performed since 1982 indicate wide variations in image quality, radiation dose, and specific equipment performance properties that affect image quality and dose in mammography (Caldwell, Fishell, Jong et al., 1992; Conway, McCrohan, Rueter et al., 1990; Galkin, Feig, and Muir, 1988; Gannon, Fields, Griffith et al, 1983; Hendrick, 1990 and 1992; Karila, 1982b and 1987; Kimme-Smith, Bassett, Gold et al., 1992; Leitz, Moores, Stieve et al., 1989). The tests listed above and in Table 4 were developed to evaluate specific aspects of equipment performance, including image quality and dose (Hendrick, Bassett, Dodd et al., 1992). Performing these tests as part of a regular quality control program allows equipment problems to be identified and corrective actions to be taken.

Film Labeling, Retention, and Lending

Figure 6. Diagram of properly labeled film

    Figure 6. Diagram of properly labeled film

• Elements:

• ID label

• Laterality/view (near axilla)

• Cassette (Arabic number)

• Technologist (initials)

• Dedicated unit (Roman number)

• Date sticker (paper adhesive)

• Technical factors

Figure 6

Table 5. Terms for mammography film labeling

Table 5. Terms for mammography film labeling

Label	Labeling code
Laterality View/position	R/L
Mediolateral oblique	MLO
Craniocaudal	CC
Mediolateral	ML
Lateromedial	LM
Magnification	M
Exaggerated craniocaudal	XCCL
Cleavage	CV
Axillary tail	AT
Tangential	TAN
Roll lateral/roll medial	RL/RM
Caudocranial (from below)	FB
Lateromedial oblique	LMO
Implant displaced	ID

Radiographic films should be retained for comparison of previous findings with new ones to assess changes (patient care and management), for legal reasons (the film is a document and may be important for insurance cases or legal actions), and for research and education. The interpreting physician, the referring provider, or the patient may be responsible for film retention and maintenance. Unless a formal contractual arrangement is created for another method of storage, the facility exposing the mammogram should be responsible for retention and storage. Patients may be allowed to retain their films if this is acceptable to them and their health care providers. When a referring health care provider sells or closes a practice office, films should be transferred to the provider acquiring the practice, to the patient, or to a provider designated by the patient. Separate storage of mammography films is neither recommended nor discouraged. It may decrease retrieval time and misfiling or loss of films, but no data exist suggesting that this results in higher quality mammography.

Original films should be loaned whenever possible. Prior mammograms are useful when interpreting current examinations and often make further followup unnecessary. Subtle changes may become apparent when current films are compared with prior films. The ACR urges mammography facilities to make original images available for use by other physicians for consultation or second opinions. Unless otherwise agreed by the parties or mandated by law, the ACR regards mammograms and written interpretations as the property of the facility that produced them, subject to the patient's right of access to this information (American College of Radiology, 1993c).

It is advisable to document each request to borrow films, noting when the films were sent, how they were sent, and when they were received. When requests for prior mammograms originate from another community or State, certified mailing will provide documentation of receipt and return. Film-lending requests should be honored immediately. The borrower is responsible for documenting receipt, safe storage, and return. If no future interventions are planned for the patient, borrowed films should be returned within 30 days.

Medical Audit

The mammography medical audit is a systematic collection and analysis of mammography results, which are compared with outcomes data. It is the only way to measure both technical and interpretive aspects of mammography performance (Bird, 1989; Robertson, 1993; Sickles, 1992; Spring and Kimbrell-Wilmot, 1987).

Medical audits permit evaluation of the ability to detect very small cancers at the expected rate, which is an important measure for any mammography practice (Robertson, 1993; Sickles, 1992; Sickles, Ominsky, Sollitto et al., 1990; Spring and Kimbrell-Wilmot, 1987). Interpreting physicians receive individualized feedback on performance, which instills confidence if results meet expectations or which identifies a need for additional training (Linver, Paster, Rosenberg et al., 1992; Reinig and Strait, 1991; Sickles, 1992; Sickles, Ominsky, Sollitto et al., 1990; Spring and Kimbrell-Wilmot, 1987). Longitudinal audit studies may detect causes of false-negative errors, allowing technical and interpretive shortcomings to be corrected (Bird, Wallace, and Yankaskas, 1992; Sickles, Ominsky, Sollitto et al., 1990; Spring and Kimbrell-Wilmot, 1987). When audit data are reviewed and acted on appropriately, the audit is a powerful education tool (Bird, Wallace, and Yankaskas, 1992). Audit results can indicate acceptable levels of performance to third-party payers and government agencies (Sickles, 1992; Sickles, Ominsky, Sollitto et al., 1990) and assist in legal cases (Brenner, 1992a; Reinig and Strait, 1991; Sickles, 1992; Spring and Kimbrell-Wilmot, 1987). Timely audits of abnormal mammograms can result in optimal followup of individual patients as a part of a risk management program (Robertson, 1993). An audit also can help monitor patient population outcomes of screening mammography, locally and through a national database (Clark, King, and Worden, 1989; Sickles, 1992; Spring and Kimbrell-Wilmot, 1987). Yearly review of audit data allows for more timely and meaningful longitudinal evaluation of individual and group performance (Linver, Paster, Rosenberg et al., 1992).

Data Collection

Recommendation: Data should be collected from the appropriate sources for all audits. (B)

Data sources should include the mammography report; information recorded by the scheduler, receptionist, and technologist; and biopsy results. If biopsy results indicate cancer, information can be found through a regional or statewide tumor registry. If no such registry is available, a definitive diagnosis of cancer or benign results can be obtained from, in order of preference, the pathology report, the referring physician or surgeon, or the patient herself. Anyone who is involved in patient care and has access to biopsy results, such as surgeons and pathologists, should cooperate in communicating these results to the mammography facility.

Recommendation: Data for the audit should be collected by a computerized program. If this is not possible, manual collection is acceptable. (B)

The volume of data to be collected for medical audit is a challenge. Data can be collected manually (Sickles, 1992; Spring and Kimbrell-Wilmot, 1987) or by computer. Customized software for medical audit has been developed (Burhenne, Hislop, and Burhenne, 1992; Haug, Tocino, Clayton et al., 1987; Heilbrunn and Graves, 1990; Linver, Paster, Rosenberg et al., 1992; Monticciolo and Sickles, 1990; Sickles, 1987 and 1992). Commercial software products are efficient, effective, and widely available. A computerized data collection program can be incorporated into a computerized reporting system (American College of Radiology, 1993a; Heilbrunn and Graves, 1990).

Recommendation: Regional or national mammography databases should be established with a major emphasis on the medical audit component. (B)

Recommendation: A medical audit should use data from regional or national mammography databases to expedite data collection, ensure completeness, and compare individual medical audit data with those of a wide variety of other practices. (C)

Collection of some data elements may be difficult because of patient mobility, performance of biopsies off site, and physicians' referral patterns and because some mammography facilities only do screening mammography. For comparisons, a mammography facility needs data that match its patient population and practice setting. Regional or national databases permit the collection of data from a wide geographic area and comparison over a wide variety of practices. A regional or national mammography database may be implemented as a voluntary, cooperative program (Murphy, Destouet, and Monsees, 1990) linked to standardized cancer registries in collaboration with State or local health departments (Clark, King, and Worden, 1989).

Table 6. Medical audit component of a regional or national (more...)

Table 6. Medical audit component of a regional or national mammography database

Identification of practice (confidential identification) Anonymous identification number of mammography interpreters Dates of audit period and number of examinations audited for each practice Patient identification number (confidential identification) compatible with database(s) enabling linkage, for example, to tumor registry Patient date of birth Type of mammogram (baseline or first-time, routine screen or diagnostic) Interpretation of mammogram Followup recommendation Dates and results of followup studies, if any If abnormality found, palpable vs. nonpalpable Results of cytology, core needle biopsy, or open biopsy Cancer data Size of each breast cancer diagnosed Histology of each breast cancer diagnosed Lymph node status Pathological stage False-negative rate True-positive biopsy rate False-positive rate Positive predictive value Overall cancer detection rate Date of patient's death

If the database is to include the function of patient monitoring and tracking, the following items comprise a minimum data set (Hurley, 1990) to be collected: Patient's name, including all prior names Patient's current address Patient's date of birth Patient identification number compatible with database(s) enabling linkage, for example, to tumor registry Patient's telephone number Patient's spoken language Dates of prior mammograms Location of prior mammograms Date of followup studies, if any Date to send patient/clinician next reminder about when next study is due

A regional or national mammography database Table 6 is a computerized method of data collection that includes the collection and analysis of medical audit data from individual practices and may include a system for patient monitoring and tracking (Burhenne, Hislop, and Burhenne, 1992; Cardenosa and Eklund, 1991; Elsenhans, 1991; Haug, Tocino, Clayton et al., 1987; Monsees, Destouet, and Evens, 1988; Monticciolo and Sickles, 1990; Robertson and Kopans, 1989; Sickles, 1987 and 1992; Tocino, 1989). Such a database may also include a population registry, which would identify women not in the screening system (Hurley, 1990).

However, before any such system can be implemented, patient confidentiality and protection of medical audit information from discovery must be ensured (Agency for Health Care Policy and Research, 1991; American Hospital Association Work Group, 1993; American Medical Association, 1988; Hurley, 1990; Murphy, Destouet, and Monsees, 1990). Current State peer review statutes protecting peer review activities, such as collection of medical audit data, apply to inpatient facilities (American Medical Association, 1988; Spring and Kimbrell-Wilmot, 1987). In many States, there is virtually no protection from discovery of quality assurance activities in ambulatory and outpatient settings (American Medical Association, 1992), where most mammography facilities function. (See Medicolegal Considerations.)

Strong Recommendation: Certain essential raw data and derived data should be obtained for a meaningful medical audit. (A)

Table 7. The essential mammography audit: the minimum (more...)

Table 7. The essential mammography audit: the minimum desired raw and derived data

Raw data (unprocessed data) Dates of audit period and total number of mammography examinations in that period Number of screened women; number of diagnostic patients[1] Number of recommendations for further imaging evaluation Number of recommendations for biopsy or surgical consultation Biopsy results: malignant or benign (keep separate data for fine needle aspiration or core biopsy cases) Tumor staging: histologic type-in situ (ductal) or invasive (ductal or lobular); grade; size; and nodal status Derived data (calculated from raw data) True positives False positives Positive predictive value If a screening/diagnostic facility, can define any of three ways: Based on abnormal screening examination Based on recommendation for biopsy or surgical consultation Based on result of biopsy If screening facility only, can define only one-based on abnormal screening examination Screening cancer detection rate Percent of minimal cancers found[2] Recall rate

[1] Separate audit statistics should be maintained for asymptomatic women and symptomatic patients.

[2] Minimal cancer is invasive cancer ≤ 1cm or in situ ductal carcinoma.

The raw (unprocessed) data recommended as minimum requirements (Table 7) have been collected in most major audits (Bird, 1989; Braman and Williams, 1989; Burhenne, Hislop, and Burhenne, 1992; Ciatto, Cataliotti, and Distante, 1987; Linver, Paster, Rosenberg et al., 1992; Lynde, 1993; Robertson, 1993; Sickles, 1992; Sickles, Ominsky, Sollitto et al., 1990; Spring and Kimbrell-Wilmot, 1987). They are necessary for proper calculation of the derived data (calculated from raw data) and for meaningful analysis of all audit data.

Table 8. The more complete mammography audit: raw data (more...)

Table 8. The more complete mammography audit: raw data to be collected

Dates of audit period and total number of examinations in that period (usually a 6- or 12-month period). Risk factors: Patient age at time of exam Breast cancer history: personal or family (especially premenopausal Hormonal replacement therapy Previous biopsy-proven lobular cancer in situ or atypical Number of mammograms: screening (asymptomatic) or diagnostic (clinical breast signs or symptoms of possible abnormality or abnormal screening mammogram) First-time examination or followup (repeat) study Mammographic interpretation and recommendation: try to conform to American College of Radiology terminology for comparison purposes: Needs additional evaluation (A) - Additional mammographic views and/or ultrasonography or other procedures Negative (N) - Routine followup Benign finding (B) - Routine followup Probably benign finding (P) - Short-interval followup Suspicious finding (S) - Biopsy should be considered Highly suggestive of malignancy (M) - Appropriate action should be taken Biopsy results: benign or malignant (keep separate data for fine needle aspiration or core biopsy cases Cancer data Mammographic findings: mass, calcifications, indirect signs of malignancy, no mammographic signs of malignancy Palpable or nonpalpable tumor Tumor staging (pathologic): histologic type, grade, size, and nodal status

Note: Bold items indicate data desired for the essential mammography audit analysis.

Table 9. The more complete mammography audit: derived (more...)

Table 9. The more complete mammography audit: derived data to be calculated

True positives, false positives, true negatives, false negatives Sensitivity Positive predictive value Based on abnormal screening exam Based on recommendation for biopsy or surgical consultation Based on results of biopsy Specificity Cancer detection rate Screening cancer detection rate Prevalent vs. incident Overall Rates within various age groups Percent of minimal cancers found[1] Recall rate

[1] Minimal cancer is invasive cancer <=1 cm or in situ ductal carcinoma.

Note: Bold items indicate data desired for the essential mammography audit analysis.

The more complete data (those listed in Tables 8 and 9) have been useful as determinants of prevalent vs. incident cancer rates, predictive value of various mammographic findings, and significance of various risk factors (Bird, 1989; Braman and Williams, 1989; Burhenne, Hislop, and Burhenne, 1992; Ciatto, Cataliotti, and Distante, 1987; Linver, Paster, Rosenberg et al., 1992; Robertson, 1993; Sickles, 1992; Sickles, Ominsky, Sollitto et al., 1990). It is recommended that these data be collected because they provide information about variables that can cause considerable fluctuation in audit results. For example, if more initial than followup mammograms are performed, the rate of cancers detected will be higher (Linver, Paster, Rosenberg et al., 1992; Sickles, 1992).

Before any calculations of derived data can be made, every mammogram should be categorized as follows:

• True positive (TP). Cancer diagnosed within 1 year after biopsy recommendation based on abnormal mammogram.

• True negative (TN). No known cancer diagnosed within 1 year of normal mammogram.

• False negative (FN). Cancer diagnosed within 1 year of a normal mammogram (Bird, 1989; Burhenne, Hislop, and Burhenne, 1992; Linver, Paster, Rosenberg et al., 1992; Lynde, 1993; Moseson, 1992; Robertson, 1993). Although other definitions of false negative exist, this definition has been the most widely applied.

• False positive (FP). Three separate definitions are seen in the literature: (1) cases recalled for additional imaging evaluation of an abnormal finding on a screening mammogram in which no cancer was found within 1 year or recalled cases not shown to be malignant within 1 year (Bird, 1989; Burhenne, Hislop, and Burhenne, 1992; Lynde, 1993; Robertson, 1993; Sickles, 1992); (2) no known cancer diagnosed within 1 year after an abnormal mammogram and recommendation for biopsy or surgical consultation (Bird, 1989; Linver, Paster, Rosenberg et al., 1992); (3) benign disease found at biopsy within 1 year after an abnormal mammogram and recommendation for biopsy or surgical consultation (Burhenne, Hislop, and Burhenne, 1992; Linver, Paster, Rosenberg et al., 1992; Sickles, 1992). This last definition of false positive is similar to the ACR BI-RADS[trademark] language.

The following derived data can then be calculated and will help to reflect the overall quality of a mammography practice:

• Sensitivity. The probability of detecting a cancer when a cancer exists, or the percentage of all patients found to have breast cancer within 1 year of screening who were correctly diagnosed at the screening session (Baines, Miller, Wall et al., 1986; Bird, Wallace, and Yankaskas, 1992; Braman and Williams, 1989; Burhenne, Hislop, and Burhenne, 1992; Linver, Paster, Rosenberg et al., 1992; Lynde, 1993; Margolin and Lagios, 1987; Robertson, 1993; Sickles, 1992; Sickles, Ominsky, Sollitto et al., 1990). Sensitivity = TP/(TP + FN).

• Positive predictive value (PPV). Three separate definitions may be applied, depending on the practice conditions and based on the above three definitions of false positive. It is important to know which definition of PPV is being used to accurately compare audit data from a mammography practice with published data. For practices performing only screening mammography, only PPV1 will be of value in evaluating data. For practices performing both screening and diagnostic mammography, all three definitions of PPV can be applied.

• PPV₁(Abnormal). The percentage of all screening mammography cases that result in a diagnosis of cancer based on an abnormal screening examination (Baines, Miller, Wall et al., 1986; Burhenne, Hislop, and Burhenne, 1992; Lynde, 1993; Robertson, 1993; Sickles, 1992). PPV₁=TP/(number of abnormal screening exams), or PPV1 = TP/(TP + FP_1).

• PPV₂(Biopsy recommended). The percentage of all screening mammography cases that result in a diagnosis of cancer based on a recommendation of consideration for biopsy (Bird, 1989; Linver, Paster, Rosenberg et al., 1992). PPV₂ = TP/(number of cases recommended for biopsy after abnormal screening exams), or PPV2 = TP/(TP + FP_2).

• PPV₃(Biopsy done). The percentage of all screening mammography cases that result in a diagnosis of cancer based on biopsies performed. This is also known as the biopsy yield of malignancy, or the positive biopsy rate (Burhenne, Hislop, and Burhenne, 1992; Linver, Paster, Rosenberg et al., 1992; Moseson, 1992; Sickles, 1992). PPV₃ = TP/(number of biopsies), or PPV₃ = TP/(TP + FP₃₎.

• Specificity. The probability of a normal mammogram report when no cancer exists, or the percentage of all patients not found to have breast cancer within 1 year of screening who were correctly identified as normal at the time of screening (Baines, Miller, Wall et al., 1986; Bird, 1989; Braman and Williams, 1989; Burhenne, Hislop, and Burhenne, 1992; Lynde, 1993; Robertson, 1993; Sickles, 1992). Specificity = TN/(FP + TN). Some variation in the range of specificity will exist depending on the definition of false positive being applied, but the variation will be small because of the very small number of false positives and the very large number of true negatives in most audit series.

• Cancer detection rate. The number of cancers detected per 1,000 women screened by mammography. This number should be available in all basic audits (Baines, Miller, Wall et al., 1986; Bird, 1989; Braman and Williams, 1989; Burhenne, Hislop, and Burhenne, 1992; Ciatto, Cataliotti, and Distante, 1987; Linver, Paster, Rosenberg et al., 1992; Lynde, 1993; Margolin and Lagios, 1987; Moseson, 1992; Robertson, 1993; Sickles, 1992; Spring and Kimbrell-Wilmot, 1987).

The following cancer detection rates can be calculated only if the appropriate raw data are collected. Although not essential to a basic audit, they provide valuable information and should be calculated when possible:

• Prevalent vs. incident cancer rates, that is, rates of cancer in first-time vs. followup exams (Bird, 1989; Burhenne, Hislop, and Burhenne, 1992; Linver, Paster, Rosenberg et al., 1992; Sickles, 1992).

• Cancer detection rates in diagnostic exams (Braman and Williams, 1989; Linver, Paster, Rosenberg et al., 1992; Robertson, 1993; Sickles, 1992).

• Cancer detection rates by age group (Bird, 1989; Burhenne, Hislop, and Burhenne, 1992; Sickles, 1992).

Separate sensitivities, PPVs, and specificities can be calculated for each of these three subgroups, yielding yet another stratum of useful audit information.

Recommendation: To improve their interpretive skills, interpreting physicians should keep track of the results of the breast biopsies they have recommended. They should attempt to increase the positive predictive value of biopsied mammographic abnormalities without decreasing the number of cancers detected. (A)

Excessive biopsies are reflected by a low positive predictive value of biopsied mammographic abnormalities, which can result in increased costs of screening mammography programs, decreased use of screening mammography, decreased compliance with recommendations for necessary biopsies by referring health care providers and women, and avoidable patient anxiety and discomfort or pain (Cyrlak, 1988; Howard, 1987). The most appropriate positive biopsy rate for abnormalities detected by mammography has not been determined. Reported positive predictive values of biopsied mammographic abnormalities range from 10 to 40 percent, even for experienced interpreting physicians; positive biopsy rates of 25-40 percent have been recommended as appropriate (Bassett, Liu, Giuliano et al., 1991; Gisvold and Martin, 1984; Hall, Storella, Silverstone et al., 1988; Hermann, Janus, Schwartz et al., 1987; Meyer, Sonnenfeld, Greenes et al., 1988).

Interpreting physicians should review mammograms and results of recommended biopsies to determine the positive predictive value of a biopsied mammographic abnormality for individual radiologists (Sickles, 1992). These rates should be kept in logs or computer databases to evaluate cumulative results, changes over time, and effects of activities to improve the accuracy of interpretations.

Data Analysis

Recommendation: To achieve optimal benefit from a mammography audit, the data should be analyzed from many perspectives. The analysis should use sensitivity (if and when measurable), positive predictive value, tumor size, node positivity, cancers found per 1,000 women screened, and recall rate. (B)

Recommendation: Audit data should be analyzed not only for a mammography interpreter group as a whole, but for each individual within that group. If available, false-negative cases should be evaluated individually to assess cause, thus further improving future outcomes. (B)

Table 10. Analysis of medical audit data: desirable (more...)

Table 10. Analysis of medical audit data: desirable goal

PPV1 based on abnormal screening examination	5-10%
PPV2 when biopsy (surgical, FNA, or core) recommended	25-40%
Tumors found-Stage 0 or 1	> 50%
Tumors found-Minimal cancer[1]	> 30%
Node positivity	< 25%
Cancers found per 1,000 cases	2-10
Prevalent cancers found per 1,000 first-time examinations	6-10
Incident cancers found per 1,000 followup examinations	2-4
Recall rate	> 85%
Sensitivity (if measurable)	<= 10%
Specificity (if measurable)	> 90%

[1] Minimal cancer is invasive cancer m% ≤ 1 cm or in situ ductal carcinoma.

Note: FNA = fine needle aspiration. PPV = positive predictive value.

Mammography interpreters should strive to reach the desirable numbers achieved by highly skilled experts in the field of mammography (shown in Table 10). Data must be analyzed to answer the three questions that most directly measure the quality of a mammographer's performance: (1) Is the mammographer finding a high percentage of the cancers that exist in that particular patient population? That is, what are the sensitivity and number of cancers found per 1,000 women screened? (2) Are these cancers being found while the numbers of biopsies and requests for further imaging evaluation of screened cases remain acceptably low? That is, what is the PPV and what is the recall rate? (3) Are a large proportion of the cancers being found still small and confined to the breast? That is, what are the numbers of minimal (invasive cancer <=1 cm or in situ ductal carcinoma) and node-negative cancers found?

Derived data are required to answer the above questions. An analysis of derived data found in the scientific literature yielded the following:

• Sensitivity. The range of sensitivity (as defined above) in most recent mammography audits is 85-90 percent (Bird, 1989; Braman and Williams, 1989; Linver, Paster, Rosenberg et al., 1992; Lynde, 1993; Margolin and Lagios, 1987; Robertson, 1993; Sickles, 1992; Spring and Kimbrell-Wilmot, 1987). Sensitivity may vary with patient age and appears to decrease in populations with denser breast tissue (Burhenne, Hislop, and Burhenne, 1992). It is among the most difficult data to obtain because its calculation requires a knowledge of the number of false negatives, information usually obtainable only through a computer linkage with a regional tumor registry. It may be necessary instead to estimate the number of false negatives to obtain an approximation of sensitivity (Sickles, 1992).

• PPV. This number is almost always measurable, using one or more of the above definitions. PPV2 (25-40 percent in most reported series) is most frequently used (Linver, Paster, Rosenberg et al., 1992; Margolin and Lagios, 1987; Sickles, 1992). Lower PPVs are acceptable when associated with greater numbers of early-stage disease and node-negative cases. If a facility performs only screening mammography, PPV1 (5-10 percent in most reported series) should be applied instead (Baines, Miller, Wall et al., 1986; Burhenne, Hislop, and Burhenne, 1992; Lynde, 1993; Robertson, 1993; Sickles, 1992). Facilities performing both screening and diagnostic mammography may find calculations of both PPV₁ and PPV₂ to be valuable. Separate PPV statistics should be maintained for cases where core or fine needle aspiration biopsy is recommended. PPV is subject to many variables, including age distribution, percentage of palpable cancers, cancer detection rate, the size and node positivity of cancers found, and sensitivity (Ciatto, Cataliotti, and Distante, 1987; D'Orsi, 1992; Kopans, 1992b; Moskowitz, 1988).

• Tumor size. In most series, more than 50 percent of tumors diagnosed by mammography are stage 0 or 1 (Burhenne, Hislop, and Burhenne, 1992; Robertson, 1993; Spring and Kimbrell-Wilmot, 1987) and more than 30 percent of cancers diagnosed by mammography are minimal cancers-invasive cancer <=1 cm or in situ ductal carcinoma (Bird, 1989; Burhenne, Hislop, and Burhenne, 1992; Linver, Paster, Rosenberg et al., 1992; Lynde, 1993; Margolin and Lagios, 1987; Moseson, 1992; Sickles, 1992). Because mortality from breast cancer is directly related to tumor size, these values should be considered desirable goals. Tumor size varies with the percentage of screening and diagnostic examinations in a mammography practice; tumors found by diagnostic examinations are invariably larger (Linver, Paster, Rosenberg et al., 1992; Spring and Kimbrell-Wilmot, 1987).

• Node positivity. Tumor size should be correlated with node positivity, which in most series is less than 25 percent (Bird, 1989; Burhenne, Hislop, and Burhenne, 1992; Linver, Paster, Rosenberg et al., 1992; Lynde, 1993; Moseson, 1992; Sickles, 1992; Spring and Kimbrell-Wilmot, 1987). Because mortality from breast cancer is directly proportional to node positivity, this value must also be considered a desirable goal.

• Cancer detection rate (cancers found per 1,000 women screened by mammography). Rates of 2-10 cancers per 1,000 have been reported in most series (Bird, 1989; Braman and Williams, 1989; Burhenne, Hislop, and Burhenne, 1992; Ciatto, Cataliotti, and Distante, 1987; Linver, Paster, Rosenberg et al., 1992; Lynde, 1993; Moseson, 1992; Robertson, 1993; Sickles, 1992; Spring and Kimbrell-Wilmot, 1987). Variability is due to differing rates of detection in first-time-screened vs. already-screened women (prevalent vs. incident cancers). Prevalent cancer rates vary from 6 to 10 per 1,000 and incident cancer rates vary from 2 to 4 per 1,000 (Braman and Williams, 1989; Burhenne, Hislop, and Burhenne, 1992; Linver, Paster, Rosenberg et al., 1992). The cancer detection rate also varies in younger vs. older women (Braman and Williams, 1989; Burhenne, Hislop, and Burhenne, 1992; Linver, Paster, Rosenberg et al., 1992; Moskowitz, 1986; Sickles, 1992) and in asymptomatic vs. symptomatic patients (Braman and Williams, 1989; Linver, Paster, Rosenberg et al., 1992; Robertson, 1993). Despite these variables the cancer detection rate serves as a relative threshold for abnormal. For example, if an audit shows that sensitivity and PPV are both acceptably high but the number of cancers found is less than 2 per 1,000, the sensitivity figure is suspect; the number of cancers eluding detection in that particular population is probably still too great, and the overall quality of the mammography should be further evaluated (Ciatto, Cataliotti, and Distante, 1987; Moskowitz, 1988).

• Recall rate. The percentage of patients for whom further imaging evaluation (coned compression views, magnification views, sonography, etc.) is recommended can be used to calculate one of the commonly used definitions of false positives and one of the definitions of PPV (see above). This is useful for all facilities, especially for those performing screening mammography only. A disproportionately high recall rate can negatively affect the cost-effectiveness and credibility of mammography (Bird, 1989). In most large reported series, the recall rate is 10 percent or less (Bird, 1989; Burhenne, Hislop, and Burhenne, 1992; Linver, Paster, Rosenberg et al., 1992; Lynde, 1993; Robertson, 1993; Sickles, 1992). This value is desirable and seems to decrease with increasing experience of the interpreting physician (Bird, 1989; Sickles, 1992).

• Specificity. Specificity is a difficult measure of quality to obtain; it is not even calculated in many large studies (Bird, 1989; Linver, Paster, Rosenberg et al., 1992; Sickles, 1992; Spring and Kimbrell-Wilmot, 1987). When calculated, it is usually found to be greater than 90 percent (Burhenne, Hislop, and Burhenne, 1992; Lynde, 1993; Robertson, 1993). Calculating specificity is difficult in that it requires knowledge of all true negatives. The number of true negatives is based on the number of false negatives, which is the least accessible information in any audit.

Two other important issues regarding analysis of audit data should be noted:

• Group audit vs. individual audit. A group audit gives greater statistical power to results, which enables comparison with overall expected rates (Linver, Paster, Rosenberg et al., 1992; Sickles, 1992). However, the multiple variables described earlier (prevalent vs. incident cancers, age of a population, ratio of screening to diagnostic mammograms, etc.) markedly influence group audit results and may render comparisons with other group audits less valuable than an intragroup comparison of individual interpreting physicians' results. A major advantage of an individual audit is that it provides a valid relative comparison among individual group members. If the performance of certain group members shows considerable variation in sensitivity and other standards, measures can be taken to improve their performance and thus improve future outcomes (Linver, Paster, Rosenberg et al., 1992; Sickles, 1992).

• Review of false negatives. As noted, these cases may be difficult to identify unless a complete tumor registry is available (Sickles, 1992). However, if available, false-negative cases should be evaluated thoroughly to assess cause (technical vs. interpretive error) (Bird, Wallace, and Yankaskas, 1992; Spring and Kimbrell-Wilmot, 1987). A thorough and critical review of false-negative cases can benefit group members and improve overall quality.

Interpreting Physicians

Interpreting physicians should:

• Be appropriately licensed to practice medicine.

• Be certified by the American Board of Radiology (ABR), the American Osteopathic Board of Radiology (AOBR), or the Royal College of Physicians and Surgeons of Canada in diagnostic radiology.

• Interpret at least 480 mammograms per year spaced at relatively even intervals.

• Have obtained 40 documented hours of continuing medical education (CME) credit or teaching in mammography prior to interpretation. (Time spent in residency will be accepted if documented by the radiologist.)

• Obtain 15 hours of CME Category I credit in mammography every 3 years.

or

• Have completed 60 hours of didactic lectures in radiation physics, radiation biology, and radiation safety and 25 hours of didactic lectures that include mammographic technique and quality assurance as well as anatomy of the breast. Successful completion must be documented by formal examination.

• Spend 16 uninterrupted weeks of full-time supervised interpretation of at least 50 mammograms per week for a total of 800 mammograms. The supervising physician should be certified as a radiologist by the ABR, AOBR, or the Royal College of Physicians and Surgeons of Canada. The supervising radiologist should spend at least 50 percent of professional time interpreting mammograms at a facility that performs at least 3,000 mammograms per year.

• Have accumulated 40 hours of CME Category I credit in mammography.

• Continue to interpret at least 480 mammograms per year spaced relatively evenly throughout the year.

• Accumulate 15 hours of CME Category I credit in mammography every 3 years.

Sensitivity, specificity, and positive predictive value have been directly related to training in mammography technique and interpretation of mammograms (Linver, Paster, Rosenberg et al., 1992). Practical experience is important when estimating mammographic interpretive ability. Residents who interpreted an average of 388 mammograms during training felt confident to practice mammography, whereas no resident who interpreted an average of 210 cases felt prepared (Resident Training in Breast Imaging in Canada: Current Status, 1992).

A poor-quality image can lead to a decrease in sensitivity and a delay in diagnosis of malignancy (Baines, Miller, Wall et al., 1986). Knowledge of the technical components of mammography must include, but is not limited to, an understanding of:

• Choices of appropriate peak kilovoltage, x-ray target, and filter material in screening and diagnostic mammography.

• Radiation dose delivered to patients at the facility.

• Ability to assess image quality and correct deficiencies related to positioning, compression, film labeling, contrast, and artifacts.

Competency should result from residency or equivalent training. Ultrasonography is the only recognized adjunctive imaging procedure for breast disease. It is clearly recognized as an accurate indicator for differentiating cystic from solid masses and can reduce the number of unnecessary biopsies (Bassett, Kimme-Smith, Sutherland et al., 1987; Feig, 1989; Jackson, 1990).

Although there is no documentation as to what constitutes adequate training for breast interventional procedures, all physicians should be trained and observed by individuals skilled in breast interventional procedures before performing these procedures on a routine basis. Indicators of successful localization have been cited in the literature (Bigelow, Smith, Goodman et al., 1985; Gallagher, Cardenosa, Rubens et al., 1989; Gisvold and Martin, 1984; Kopans and Swann, 1989; Landercasper, Gundersen, Gundersen et al., 1987; Norton, Zeigman, and Perlman, 1988; Tinnemans, Wobbes, Hendriks et al., 1987).

Specimen radiography is necessary for verifying removal of a nonpalpable finding (Gallagher, Cardenosa, Rubens et al., 1989; Homer, 1980; Kopans, Meyer, Lindfors et al., 1985; Kopans and Swann, 1989).

A physician, usually the interpreting physician, assumes responsibility for delivery of a technically adequate mammogram (Brenner, 1992a; Dodd, 1989; Reinig and Strait, 1991; Tabar and Dean, 1985).

In diagnostic imaging, studies should be correlated with clinical concerns and/or findings. Comparison of current and prior films enhances diagnostic capability, reduces the number of unnecessary procedures, and is particularly important when following a likely benign finding. In mammography, small changes between examinations may indicate a malignant process. Conversely, a lack of change over a relatively long time suggests a negative or benign condition (Goin, Haberman, Linder et al., 1983).

The presence of an interpreting physician on site during a diagnostic examination is important but may not be possible in each clinical setting and under every condition. For example, in rural facilities, the interpreting physician may be off site but leave the radiologic technologist specific instructions about a diagnostic examination. Another example in which the interpreting physician would not be on site is a situation in which the radiologic technologist becomes aware of a palpable abnormality in a woman having a screening examination and identifies the need for placement of a BB (radiopaque marker).

Interpreting physicians should assume responsibility for delivery of a technically adequate mammogram (Brenner, 1992a; Dodd, 1989; Reinig and Strait, 1991; Tabar and Dean, 1985). An interpreting physician usually should be present during a diagnostic mammogram to review the films, perform correlative breast examination if necessary, and answer any questions the woman may have. Diagnostic views are used in addition to the standard views in order to localize, confirm, or better define abnormalities, avoiding unnecessary biopsies or confirming the suspicious nature of a lesion (Berkowitz, Gatewood, and Gayler, 1989; Faulk and Sickles, 1992; Mitchell, Mitchell, and Nunnerly, 1991).

A properly designed audit is probably the most useful method for assessing the success of a screening practice, indicating acceptable levels of performance to third-party payers, and uncovering performance deficiencies (Sickles, Ominsky, Sollitto et al., 1990). (See "Medical Audit" in Chapter 5.)

Interpreting physicians should send results directly to the woman as well as to the referring health care provider to ensure that the woman receives her results, with the ultimate goal of reducing mortality from breast cancer. Both the interpreting physician and the referring or designated provider should convey results to the woman. (See "Communicating Results" in Chapter 4.)

Radiologic Technologists

Radiologic technologists should:

• Be certified in radiography by the American Registry of Radiologic Technologists (ARRT) or hold an unrestricted State license, where applicable. (Unrestricted State license means that the radiologic technologist is licensed to perform all radiologic procedures.)

• Understand breast anatomy, physiology, and pathology; technical factors; and radiation protection as related to the breast.

• Demonstrate competence in breast positioning and compression.

• Obtain 15 hours of continuing medical education units in mammography every 3 years.

Radiologic technologists should:

• Pass the advanced qualification examination in mammography administered by the ARRT.

or

• Receive 40 hours of specialized education in mammography: anatomy, physiology, pathology, proper use of mammography equipment and accessories, identification of equipment malfunction, standard processing techniques, mammographic technique, mammography positioning (including hands-on instruction), quality assurance procedures and applications, radiation protection, psychological and sociological aspects of breast screening, communication skills, recognition of pathological conditions and their subsequent treatment, and research related to breast screening.

• Perform a minimum of 100 supervised examinations and attend film-reporting sessions with radiologists. A minimum of five examinations per week is considered necessary to prove competency.

The radiologic technologist should evaluate mammograms for technical quality and proper labeling.

Safety precautions are discussed in Morbidity and Mortality Weekly Report (MMWR, 1988).

Medical Physicists

Because of the current limited numbers of certified physicists in certain geographic locations, the following alternative criteria can, for an interim period, qualify individuals for the practice of diagnostic radiological physics in mammography:

• A Master of Science, Master of Arts, or higher degree in an appropriate field from an accredited institution. Appropriate fields include physics, applied physics, radiological physics, biophysics, health physics, engineering, and public health when the bachelor's degree is in a physical science.

• Training in biological sciences.

• At least 1 year of training in diagnostic radiological physics.

• At least 2 years of experience in conducting mammography equipment performance evaluations under the supervision of a qualified medical physicist.

In addition to either set of qualifications, individuals practicing diagnostic radiological physics in mammography should receive at least 15 hours of documented CME in mammography physics every 3 years.

The Mammography Quality Standards Act of 1992, the Medicare Coverage of Screening Mammography Interim Final Rules of 1990 (Department of Health and Human Services, 1990), and the ACR Mammography Accreditation Program (Hendrick, Smith, and Wilcox, 1993) all require that a medical physicist conduct at least annual surveys of mammography equipment and oversee the facility's quality control program.

Equipment Service Personnel

An appropriately trained person will provide better service for a given piece of equipment. Because consistent and predictable equipment performance is vital for obtaining optimum image quality, the role of the equipment service person should not be underestimated.

Breast Cancer Screening and Diagnosis

Referring providers should ensure that women have thorough clinical breast examinations (CBEs) as well as routine mammography. Mammography can detect breast cancer when it is too small to be detected by CBE. However, mammography in combination with CBE has resulted in a higher breast cancer detection rate and a greater decrease in mortality than when mammography or CBE was used alone (Chu, Smart, and Tarone, 1988; Seidman, Gelb, Silverberg et al., 1987). The survival rate of women with nonpalpable breast cancer detected by mammography alone is greater than the survival rate of women whose cancer is palpable (Seidman, Gelb, Silverberg et al., 1987).

Discomfort during the examination is among the reasons cited by women for not adhering to recommended guidelines for screening mammography (Marchant and Sutton, 1990). There is evidence that routine screening mammography should not be done the week before menstruation (for women whose breasts are tender at this time) or at other times when the breasts are tender (Brew, Billings, and Chisholm, 1989; Jackson, Lex, and Smith, 1988; Stomper, Kopans, Sadowsky et al., 1988). Breast tenderness can impair the radiologic technologist's ability to achieve optimal breast compression. However, women should be scheduled for diagnostic mammography as soon as possible.

Women who have significant breast pain may be advised to take a mild over-the-counter analgesic, such as acetaminophen, salicylates, or nonsteroidal anti-inflammatory agents, about 1 hour before undergoing mammography. Women should be reassured that adequate compression can usually be accomplished without pain (Brew, Billings, and Chisholm, 1989; Jackson, Lex, and Smith, 1988; Stomper, Kopans, Sadowsky et al., 1988). Most women who have had mammograms would not defer future mammograms because of pain or discomfort (Jackson, Lex, and Smith, 1988; Stomper, Kopans, Sadowsky et al., 1988). Studies have shown that women are more likely to have pain if they expect it (Rutter, Calnan, Vaile et al., 1992). Women who have preexisting pain are less likely to tolerate compression and are candidates for mild analgesics prior to mammography (Brew, Billings, and Chisholm, 1989).

Screening mammography is an x-ray examination to detect unsuspected breast cancer at an early stage in asymptomatic women; it usually consists of two views of each breast. The interpreting physician may or may not be on site for screening mammography. Diagnostic mammography is an x-ray examination used to evaluate a patient with a breast mass or masses, other breast signs or symptoms (spontaneous discharge from the nipple, skin changes), an abnormal or questionable screening mammogram, a history of breast cancer with breast conservation, or special cases such as augmented breasts. The diagnostic mammogram should be correlated with known physical findings and symptoms. Diagnostic mammography may require additional views of the breast to better visualize the area of concern; it may also include the use of other breast imaging modalities, such as ultrasonography (American College of Radiology, 1990). The interpreting physician usually is on site during performance of diagnostic mammography.

If an abnormality is found on clinical examination, the patient should be referred for diagnostic mammography, which should be performed as soon as possible and at least within 1 month. Because diagnostic mammography generally takes more time to perform and usually requires the presence of the interpreting physician, it is important for the referring provider to specify at the time of referral whether diagnostic or screening mammography is being requested.

Disability usually does not preclude screening or diagnostic mammography. It is important to communicate special patient needs or disabilities such as severe scoliosis to the mammography facility before the examination.

Breast pain is the most common symptom associated with the breast. When breast cancer presents as breast pain, it is almost always associated with a palpable mass, nipple retraction, or other physical signs. Therefore, women presenting with breast pain should have a thorough CBE as part of their initial evaluation.

Diagnostic Mammography

When there is a palpable abnormality, mammography will be done differently. Therefore, it is important to tell the interpreting physician of any palpable findings or other clinical concerns before mammography.

In two retrospective series, malignancy was diagnosed in 4 percent of women evaluated for spontaneous nipple discharge (Devitt, 1985; Murad, Contesso, and Mouriesse, 1982). Malignancy may be associated with serous, sanguineous, or serosanguineous discharge. Nonspontaneous nipple discharge is common, especially in premenopausal women (Newman, Klein, Northrup et al., 1983), and should not be considered a sign of malignancy. However, the etiology of unilateral, spontaneous nipple discharge should be resolved regardless of mammogram results.

One month was considered a reasonable timeframe in which to accomplish diagnostic mammography, although there are no data to support it. The reason to perform diagnostic mammography in a timely fashion is for the best management of the patient, with the goal of decreasing mortality due to breast cancer. Empiric data are scarce in the medical and legal literature regarding the interval between the decision to obtain diagnostic mammography and the completion of diagnostic mammography (Parver, 1983; Spratt and Spratt, 1990). However, delay in the diagnosis of breast cancer is the reason for a high percentage of malpractice litigation and claims paid (Adamson, Tschann, Guillon et al., 1989; American College of Obstetricians and Gynecologists, 1990; Cohn, 1991; Unger, 1990).

It is also important for the patient to be aware of any clinical findings and their location.

Figure 7. Graphic representation of breast

    Figure 7. Graphic representation of breast

Note: The referring provider may use a diagram like this to denote the location of a palpable mass.

Figure 7

Aspiration of a suspected cyst is often the initial step in the diagnostic workup of a palpable breast mass (Hindle and Hale, 1992). The decision to attempt aspiration of a suspected breast cyst will probably be based on several factors, including the size of lump and ease of access, the strength of the clinician's suspicion that a mass is a cyst, the availability of mammography, the availability of breast ultrasonography, and cost considerations. Two case series indicate a number of false-positive mammograms based on artifact from presumed hematoma formation after fine needle aspiration biopsy (FNAB). Seventeen false-positive mammograms were reported in a series of 80 women who had undergone FNAB up to 1 month before mammography (Klein and Sickles, 1982; Sickles, Klein, Goodson et al., 1983). All the false positives occurred in women in whom mammography was carried out within 1 week of aspiration. Mammogram appearance was altered in 3 of 52 women receiving mammography before and 1 week after FNAB (Horobin, Matthew, Preece et al., 1992). In two of these cases, densities present on postaspiration mammography would have been greater cause for concern if preaspiration films had not been available. Although no false-negative mammograms were described in these series, malignant changes might be obscured by postaspiration hematomas. Therefore, if mammography or sonographic findings are confusing because of aspiration, mammography can be repeated after 2 weeks, when findings secondary to hematoma should have resolved. Alternatively, the mammogram could be delayed for 2 weeks following aspiration.

Small retrospective studies of women with biopsy-proven breast cancers indicate that negative mammography in the presence of a palpable mass can be associated with a delay in the diagnosis of breast cancer (Langlands and Tiver, 1982; Mann, Giuliano, Bassett et al., 1983; Niloff and Sheiner, 1981). The sensitivity of modern mammography is known to be less than 100 percent. Recent data indicate that the sensitivity of screening mammography ranges from 85 to 90 percent when performed at some exemplary mammography sites. These data indicate that there are some breast cancers that will not be found by mammography and will require detection by other means, usually from signs or symptoms or physical palpation. It is important to avoid delay in evaluating breast masses to minimize the size and stage of detected cancer.

The purpose of mammography in the woman with a palpable breast lump is to further define the lump and to rule out the presence of nonpalpable breast cancer in the ipsilateral or contralateral breast. The purpose of mammography is not to delay the biopsy of a clinically suspicious abnormality.

In a correlative breast examination, a radiopaque marker (BB) is placed directly over the palpable abnormality to indicate its exact location (Eklund and Cardenosa, 1992). The BB directs attention to the area of concern and enables the interpreting physician to determine whether abnormal mammography findings match the location of the palpable abnormality. If the palpable abnormality does not appear on the films, additional views may be taken (Faulk and Sickles, 1992).

After the mammograms have been done, the interpreting physician may conduct another correlative breast examination to better understand the clinical findings and to properly correlate them with the findings on the mammogram. Subtle changes on the mammogram may have more significance when the clinical findings suggest a possible breast cancer (Eklund and Cardenosa, 1992).

The wide variation in the yield of cancers from biopsies reflects differences in the population of women studied, the experience of the physicians interpreting mammograms, and the philosophies of the interpreting physician and referring health care provider concerning the percentage of biopsies that should yield breast cancer (Howard, 1987). Benign biopsies result from CBE as well as from mammography. Overall, the cancers found by mammography are detected at an earlier stage than those found by CBE (Bassett, Liu, Giuliano et al., 1991).

Women With Breast Implants

Currently, no published data show an increase in risk of breast cancer among women with implants for breast augmentation. Studies to assess the risk are underway. These women should be followed at the same interval as women without implants.

Although unsuspected breast cancer can be detected on mammograms of women with implants (Destouet, Monsees, Oser et al., 1992), mammography is more difficult to perform and may be less effective in these women (Bassett and Brenner, 1992). Mammography has not been shown useful for breast cancer detection when implants have been used for breast reconstruction after total mastectomy; regular CBE should be performed in these cases.

Mammography of asymptomatic women with breast implants should include both implant-included and implant-displaced views (Eklund, Busby, Miller et al., 1988). In the implant-displaced views, the radiologic technologist manually displaces the implant toward the chest wall while bringing breast tissue forward so that it can be adequately compressed. This maneuver results in an improved image of the anterior breast tissue.

Mammography Views, Compression, and Positioning

The primary goal of positioning for screening mammography is to show all of the breast tissue on the two standard views (Eklund and Cardenosa, 1992). For diagnostic mammography, the most commonly used additional techniques are "spot compression" and/or "magnification," which are intended to better define a possible mammographic abnormality. Spot compression involves the use of a smaller compression device to optimize compression over a local area of concern and to displace overlying tissues away from the area of concern (Berkowitz, Gatewood, and Gayler, 1989). Magnification is used to improve the visibility of the details of the margins of a mass or to better see and characterize microcalcifications (Sickles, 1979 and 1980).

Proper compression is essential for high-quality mammography (Hendrick, Bassett, Dodd et al., 1992; National Council on Radiation Protection and Measurements, 1986). Compression involves pressing the breast between a clear-plastic, movable plate (the compression device) and the platform holding the film during mammography. Compression:

• Reduces breast thickness, thus (1) improving the visualization of structures within the breast that may be indicative of breast cancer and (2) enhancing image contrast (by decreasing scattered radiation) and significantly lowering radiation dose.

• Holds the breast still, thus preventing motion that can blur the image of breast structures.

• Spreads the tissues in the breast, thus reducing the possibility that a lesion might be obscured by overlying tissues and therefore missed.

Women 50 and Over

Women 40-49

Women Under 40

Routine screening mammography is not generally recommended for asymptomatic women under age 40. In general, the risk of developing breast cancer is lower for women in this age group than for older women. For women under 40, decisions to perform screening mammography and selection of intervals between examinations should be made on a case-by-case basis. Referring providers should directly contact the interpreting physician when scheduling mammography for women under 30.

Breast density is widely believed to decrease the discriminatory capability of mammography (Hoeffken and Lanyi, 1977) in women under 40, who are likely to have denser breasts (Bassett, Ysrael, Gold et al., 1991; Ciatto, Bravetti, Bonardi et al., 1990; Meyer, Kopans, and Oot, 1983; Williams, Kaplan, Petersen et al., 1986). Both lower prevalence of breast cancer and decreased sensitivity of mammography in this age group would be expected to reduce the potential benefits of screening mammography in asymptomatic women (Harris and Jackson, 1989).

Pregnancy and lactation (Berkowitz, Gatewood, Goldblum et al., 1990; Stomper, Van Voorhis, Ravnikar et al., 1990) can increase breast density. Resumption of menses is currently identified as the marker for scheduling a screening mammogram in post partum or lactating women (American College of Radiology, 1992). By 24 weeks post partum, 85 percent of nursing mothers and 90 percent of nonnursing mothers will have resumed menstruation (Vorherr, 1974).

Women with a first-degree relative (i.e., mother, daughter, sister) who was diagnosed with breast cancer have an increased relative risk of breast cancer compared to women who do not have a first-degree relative with breast cancer (Colditz, Willett, Hunter et al., 1993). Relative risk is defined as the rate of breast cancer incidence in women who have the risk factor of a first-degree relative with breast cancer divided by the rate of breast cancer incidence in women who do not have the risk factor. Higher risks have been reported for some subgroups, such as women who have first-degree relatives with premenopausal or bilateral breast cancer (Anderson, 1971 and 1974; Anderson and Badzioch, 1985; Ottman, Pike, King et al., 1983). Many protocols suggest beginning mammographic screening of women with a first-degree relative with premenopausal or bilateral breast cancer at an earlier age, usually at or before the age of the relative at diagnosis (King, Rowell, and Love, 1993).

False-negative rates in symptomatic women appear to be higher for women under 40. It is important that an indicated biopsy not be delayed because of a negative mammogram. In several small case series of women under 40 (Cohen, Mintzer, Matthies et al., 1985) or 35 (Ciatto, Bravetti, Bonardi et al., 1990; Harris and Jackson, 1989) with biopsy-proven breast cancer, mammographic changes suggestive of malignancy were absent in 25-50 percent of initial mammograms. However, only 10 and 12 percent of initial mammograms were negative in two other series of symptomatic women under 35 who were diagnosed with breast cancer (Meyer, Kopans, and Oot, 1983; Shaw de Paredes, Marsteller, and Eden, 1990). One study (Bassett, Ysrael, Gold et al., 1991) reported three negative mammograms in six patients under 35 with breast cancer and noted that the mammographic diagnosis of "benign-appearing mass" contributed to a delay in diagnosis in two cases.

Communicating Results

Communication of mammography results is an important component of clinical practice. Various members of the panel, who represented referring providers, interpreting physicians, and consumers, realize that this issue is controversial and there are a variety of ways communication is accomplished. However, the guideline that was developed has as its goal the method of communication most likely to ensure that the woman receives her results, so that the outcome is reduced mortality from breast cancer.

Additional information on communicating results is found in Chapter 4 (see "Communicating Results") and Chapter 6 (see "Interpreting Physicians").

Failing to communicate mammography results is a common problem (Robertson and Kopans, 1989). Mechanisms are needed to ensure that results, especially abnormal results, are communicated to women as soon as possible.

The primary concern in monitoring and tracking women with normal results is compliance with regular screening mammography. The responsibility for that effort should lie with the referring provider and the woman. Screening reminders may be communicated by the referring health care provider rather than by the mammography facility, according to prearranged protocols. Computerized monitoring and tracking systems may be used to automatically generate the reminder.

Communication of recommendations for an additional workup by the staff of the mammography facility directly to women has been shown to be effective (Cardenosa and Eklund, 1991). Even when women and referring providers are informed, compliance with recommendations for periodic followup of low-suspicion lesions can still be a problem (Helvie, Pennes, Rebner et al., 1991). Using computers to track compliance with recommendations is particularly effective (Monticciolo and Sickles, 1990).

When mammography results are abnormal, a telephone call to the health care provider before a report is sent may identify and resolve any vagueness in the provider-patient status. For a self-requesting woman with an abnormal finding, this call will significantly reduce the chance that she will slip through the cracks.

Communicating abnormal results only to the referring health care provider does not guarantee that appropriate followup will occur (Langer, 1994; Monticciolo and Sickles, 1990; Robertson and Kopans, 1989). Compliance with followup increases when results are directly reported to the woman and the significance of positive findings is explained (Cardenosa and Eklund, 1991; Dershaw, Liberman, and Lippin, 1992; Haug, Tocino, Clayton et al., 1987; Monsees, Destouet, and Evens, 1988; Rubin, Frank, Stanley et al., 1990).

Recordkeeping

The content of the office record kept by the referring provider should include:

• Reason for the mammography examination.

• The mammography report from the interpreting physician.

• All followup records and communications with the woman (by telephone or in writing).

• Information for comparison when future mammography studies are done, such as facility name and location and date of examination.

Optional additional data that may be kept in the woman's record are:

• Information for a patient mammography reminder system.

• Any other information that may be needed to document recommendations and communications that have taken place.

The usual repository for mammography reports is the patient's general medical record. The health care provider's records system may be manual, automated, or computerized, but its design should address durability, security, confidentiality, storability, and retrievability. Four scientific articles (Adams and Campbell, 1985; McDonald, Hui, Smith et al., 1984; Melcher, 1986; Monticciolo and Sickles, 1990) describe automated and computer-assisted recordkeeping systems. None of the systems described is clearly superior. (See also "Recordkeeping" in Chapter 4.)

Adverse Consequences of Mammography

Excessive biopsies are a possible adverse consequence of mammography. There is also a low probability of breast cancer induction due to radiation exposure. Other problems associated with mammography include inadequate communication of results, the need to return for additional or repeat views, the inconvenience of scheduling mammography, pain or discomfort, false reassurance, delay in diagnosis and treatment, and cost. Adverse consequences and other possible problems are discussed in Chapter 8.

Mammography Standards

A 1990 study of mammography sites by the General Accounting Office revealed significant variations in quality assurance standards among sites (General Accounting Office, 1990). As of October 1, 1994, the Mammography Quality Standards Act (MQSA) requires that mammography facilities in the United States be certified by FDA to meet standards for equipment, personnel, and recordkeeping. Certification requires being accredited by an FDA-approved accreditation body and meeting additional quality standards that are verified by site inspections performed by qualified MQSA inspectors. Facilities must display the FDA certificate. However, Veterans Health Administration facilities have their own mammography quality assurance program that parallels MQSA, and they do not require FDA certification.

Facilities may be certified for an interim 6-month period while they are in the process of receiving accreditation. Currently, the American College of Radiology is an approved accreditation body and one State agency (Iowa) is an approved accreditation body for facilities in that State. It is likely that other State agencies may become approved accreditation bodies.

Other Breast Imaging Modalities

Modern mammography has been demonstrated to have high sensitivity and specificity for breast cancer detection. Other modalities have been introduced and evaluated for the detection of breast cancer. As screening tools for breast cancer, thermography and light scanning (diaphanography or transillumination) have not been shown to be of value. Ultrasonography is less sensitive than mammography as a screening tool for breast cancer but has a valuable diagnostic role in distinguishing cysts from solid masses in previously detected masses. This modality is also useful in detecting clinically palpable lesions not visible on mammography. Xeroradiography has been shown to have sensitivity and specificity comparable to that of screen-film mammography but has higher radiation doses and greater maintenance problems. Newer modalities, such as breast magnetic resonance imaging and digital mammography, are currently being developed and evaluated for diagnostic use.

Excessive Biopsies

Excessive biopsies can result in increased cost, decreased use of screening mammography, decreased compliance with recommendations for necessary biopsies by referring health care providers and women, and avoidable patient anxiety and discomfort or pain (Cyrlak, 1988; Howard, 1987). The wide variation in the yield of cancers from biopsies reflects differences in the population of women studied (e.g., surgical positive predictive value is higher in older women), the experience of the physicians interpreting mammograms, and the philosophies of the interpreting physician and referring health care provider concerning the percentage of biopsies that should yield breast cancer (Howard, 1987). Benign biopsies result from clinical breast examination (CBE) as well as from mammography and, overall, the cancers found by mammography are detected earlier (Bassett, Liu, Giuliano et al., 1991).

Several strategies can be used to increase the positive predictive value of a biopsied mammographic abnormality. Developing strict criteria for biopsies and using a complete mammographic workup can identify many abnormalities as probably being benign, thus reducing the number of unnecessary biopsies (Hall, Storella, Silverstone et al., 1988). The breast imaging workup often includes ultrasonography to identify cysts for which biopsy is not necessary (Hilton, Leopold, Olson et al., 1986). For lesions that are probably benign, periodic followup can be used instead of biopsy (Brenner and Sickles, 1989). If there is still a question about whether a biopsy is necessary, the interpreting physician should discuss the pros and cons of the biopsy with the referring physician and the woman. A second opinion from an experienced interpreting physician can be helpful in resolving equivocal cases (Hall, 1990).

Radiation Exposure

Several studies have estimated the risk of radiogenic breast cancer on the basis of an increased incidence of breast cancer in women who received extremely high levels of radiation exposure (Breslow, Thomas, and Upton, 1977; National Academy of Sciences, 1980 and 1990; National Council on Radiation Protection and Measurements, 1986; National Institutes of Health, 1985). The most recent estimate in the report of the National Academy of Sciences Committee on Biological Effects of Ionizing Radiation (BEIR-V) is likely to be the most accurate because it is based on the longest term followup of exposed women and on the most detailed analysis of collective data (National Academy of Sciences, 1990). The BEIR-V report states that the risk of radiation-induced breast cancer begins 5-10 years after exposure, with the probability of incidence peaking 15 years after exposure and the probability of mortality peaking 20 years after exposure. There is a strong dependence of risk on age at exposure, with women younger than 40 having a higher, but still small, risk of radiation-induced breast cancer. (It is not recommended that normal-risk, asymptomatic women begin screening mammography before age 40.)

Table 12. Added lifetime risk of breast cancer mortality (more...)

Table 12. Added lifetime risk of breast cancer mortality due to radiation exposure from a two-view mammogram

Age at exposure or age at start of annual screening (years)	From a single two-view mammogram	From annual screening starting at age indicated
	(risk per 100,000 women)
20	2.5	54.1
25	2.3	41.9
30	2.0	30.9
35	1.7	21.4
40	1.3	13.8
45	0.9	8.9
50	0.6	3.9
55	0.3	1.5
60	0.1	0.4
65	0.02	0.04

Note: Average glandular breast dose is 3 mGy. Assumes screenings beginning at the specified age and continuing to age 75.

Source: Hendrick, Ritenour, and Feig (1994).

To put the potential risk of breast cancer death due to screening mammography in perspective, the lifetime risk of breast cancer death due to the radiation from a two-view screening mammogram at age 45 is approximately equal to the risk of death from traveling 450 miles by car (accident) or smoking three cigarettes (lung cancer) (Feig and Hendrick, 1992; National Safety Council, 1988; Pochin, 1978).

Inadequate Communication of Results

Failing to communicate mammography results is a common problem (Robertson and Kopans, 1989). A report to the referring physician is not sufficient if the results are abnormal, because the report may not be received or it may not be read. A phone call to the referring health care provider should be made when there are abnormal results. However, mechanisms are needed to ensure that results, especially abnormal results and recommendations for future action, are communicated to women. Special protocols should be in place for self-requesting and self-referred women to ensure that they receive their results. Usually this involves issuing a written report in lay language directly to the woman (Monsees, Destouet, and Evens, 1988). Communication of results is discussed in Chapter 4.

Returning for More Views

Having to return for additional or repeat views can cause substantial anxiety (Lerman, Trock, Rimer et al., 1991). If the reason is suboptimal technique, women should not be charged for repeat mammography. Women who have abnormal results requiring additional views are more likely than other women to feel that the mammography facility staff has not been supportive (Orton, Fitzpatrick, Fuller et al., 1991). Women should be able to speak directly to the interpreting physician either during the visit or by phone. It is important to be supportive of women with unusual anxiety and to identify women who may need counseling (Bull and Campbell, 1991). Although the degree of anxiety is related to the degree of suspicion of abnormality, even a benign result may not eliminate ongoing psychological distress. The psychological sequelae do not appear to interfere with subsequent adherence to recommendations for screening mammography (Lerman, Trock, Rimer et al., 1991).

Scheduling Inconvenience

Having to make a separate appointment for a mammogram in addition to a visit to a primary care provider can result in additional time lost from work, inconvenience, and decreased use of mammography. A perception that the mammography appointment will be time consuming, troublesome, and inconvenient also decreases use of screening mammography (Fajardo, Saint-Germain, Meakem et al., 1992; Rimer, Keintz, Kessler et al., 1989). Referring providers may not have adequate office staff for scheduling mammography appointments, which may involve additional efforts such as authorization for work absenteeism, monitoring compliance, interpreting results and recommendations, reporting results to patients, and scheduling followups (Costanza, D'Orsi, Greene et al., 1991).

Women in underserved areas may have to travel considerable distances to find a facility certified by the Food and Drug Administration. Transportation subsidies may be needed to provide access to mammography for women in these areas (Artz, Brown, and Barrett, 1992).

Another barrier to screening mammography is age. Screening rates decline among women ages 60 and over compared with women in their 40s and 50s (Horton, Romans, and Cruess, 1992).

Minority women may have specific concerns and problems that add further barriers to making an appointment. Certain groups of women may underuse mammography because of language, cultural, and economic barriers (Lovejoy, Jenkins, Wu et al., 1989). Additional steps to increase the use of screening mammography by minority women include educating mammography facility staff to be sensitive to cultural and ethnic differences, employing translators or multilingual receptionists, and producing and disseminating educational materials for women of various ethnic and cultural backgrounds (Fox, Klos, Worthen et al., 1990; Stein, Fox, and Murata, 1991).

Strategies that can be used to overcome these barriers include offering mammography at more convenient times by extending daily hours of operation and opening on weekends (McCoy, Nielsen, Chitwood et al., 1991). Mobile vans (Monsees and Destouet, 1992) and corporate-sponsored work site mammography programs (Kessler, Rimer, Devine et al., 1991) may increase access and utilization of mammography.

Pain and Discomfort

When properly performed, mammography usually is not painful. If women have unnecessary pain and severe discomfort during mammography, they may not return for future screening examinations. Routine mammography should not be done at times when the breasts are tender or in the week before menstruation for women who have breast pain associated with menses (Brew, Billings, and Chisholm, 1989; Jackson, Lex, and Smith, 1988; Stomper, Kopans, Sadowsky et al., 1988). A mild, over-the-counter analgesic such as acetaminophen, salicylates, or nonsteroidal anti-inflammatory agents may be useful for some women who have breast tenderness or pain.

False Reassurance and Delay in Diagnosis

The purpose of mammography for a patient with a palpable breast lump is to further define the lump and to rule out the presence of nonpalpable breast cancer in the ipsilateral or contralateral breast. The purpose of mammography is not to delay the biopsy of a clinically suspicious abnormality.

Mammography may provide false reassurance that a clinical finding is not significant and lead to a delay in diagnosis. Although mammography is more effective overall than CBE in detecting breast cancers, mammography will not show all clinically evident breast cancers (Feig, Shaber, Patchefsky et al., 1977). In the Breast Cancer Detection Demonstration Project, conducted in the 1970s, 9 percent of breast cancers were detected only by CBE (Baker, 1982). Screening for breast cancer is best done by combining mammography with a thorough CBE.

Biopsy of a clinically suspicious abnormality should not be delayed because of a negative mammogram. Delay in diagnosis of breast cancer may lead to disease progression and may adversely affect survival (Mann, Giuliano, Bassett et al., 1983; Wilkinson, Edgerton, Wallace et al., 1979). Delay in diagnosis of breast cancer is the most expensive and second most common cause of malpractice claims against physicians (Physician Insurers Association of America, 1990). A caveat, such as "mammography is not a substitute for biopsy," routinely stamped on every mammography report, is not an effective method for conveying this information (Brenner, 1992a). These routine caveats tend to be ignored and to lower overall confidence in mammography.

Costs

Fees charged for mammography vary substantially, with the lowest fees generally charged in high-volume screening settings and the highest fees generally charged by office-based radiologists in private practice. Screening costs range from $40 to $275, with a national average of about $89 (Houn and Brown, 1994). Insurance programs, both public and private, do not always offer reimbursement for screening mammography. Surveys of physicians indicated that cost influences their decision to refer women for mammography. Whenever possible, screening facilities should offer flexible payment arrangements or sliding-scale fees.

Diagnostic mammography is generally more expensive than screening mammography. The practice of setting a flat fee for both screening and diagnostic mammography should be discouraged because it artificially raises the cost of the screening examination. A recent National Cancer Institute survey determined that about 40 percent of mammography facilities do not explicitly distinguish between screening and diagnostic mammography in their charges, and that the remainder classify only about 50 percent of mammography examinations as screening (Houn and Brown, 1994).

Compliance with regular screening is currently highest among educated middle- and upper-income women. Access to screening for economically disadvantaged women is often constrained by cost. Low-cost and government-sponsored screening programs are sometimes available. Nevertheless, many economically disadvantaged women have never had a mammogram or are not screened regularly; this is thought to contribute to the disproportionately high mortality rates seen in some ethnic groups in which breast cancer is often detected at later, less treatable stages.

False-positive screening mammograms that result in unnecessary diagnostic procedures and biopsies add substantially to the cost of the initial examination but provide necessary confirmation that a finding is benign. Additional views and ultrasonography may eliminate the need for a biopsy. Less expensive, more efficient alternatives to excisional biopsy are increasingly being used. Stereotactically guided needle biopsy and ultrasound guided needle biopsy are accurate and less expensive alternatives to open biopsy.

Mammography that results in the detection of an abnormality generates additional costs for diagnostic procedures, treatment, and rehabilitation (including individual and group support), as well as hidden costs such as insurance copayments, time away from work, transportation, lodging, and at-home child or elder care expense. Often, hidden costs are unanticipated and not reimbursable by insurance. However, treating early-stage breast cancer is substantially less costly than treating late-stage breast cancer.

Ultrasonography

The sensitivity and specificity values reported for ultrasonography are unacceptably low and do not justify its use as a screening tool for breast cancer. Bassett, Kimme-Smith, Sutherland et al. (1987) argue convincingly that sonography is useful in ruling out biopsy in certain cases.

Sensitivities and specificities of Doppler ultrasonography are higher than those of standard ultrasonography and are usually comparable with those of mammography in the diagnostic setting. In the largest study of Doppler ultrasonography (Burns, Halliwell, Wells et al., 1982), sensitivity and specificity were similar to those in a study of mammography by Robertson (1993).

Magnetic Resonance Imaging

Magnetic resonance imaging as a screening tool for breast cancer has not been studied. Two studies, only one of which was blinded, give some meaningful data on its efficacy as a diagnostic tool (El Yousef, O'Connell, Duchesneau et al., 1985; Lewis-Jones, Whitehouse, and Leinster, 1991); more research needs to be done before this method can be recommended as a diagnostic adjunct to mammography.

Light Scanning

Only two studies of the sensitivity and specificity of light scanning as both a screening and diagnostic tool give screening results (Alveryd, Andersson, Aspegren et al., 1990; Ohlsson, Gundersen, and Nilsson, 1980). The Ohlsson, Gundersen, and Nilsson results are comparable with mammography results, but the sample sizes are relatively small. The Alveryd, Andersson, Aspegren et al. results show a sensitivity of 48.4 percent, which is unacceptable. Results from diagnostic light scanning studies tend to show lower sensitivities and specificities than are found in diagnostic mammography studies. Sensitivities near 50 percent (inadequate to justify the use of light scanning as a diagnostic adjunct to mammography) are common.

Thermography

A study by Amalric, Giraud, Altschuler et al. (1982) is the only report of reasonable values for sensitivity and specificity of thermography as a diagnostic tool for breast cancer detection. A study by Gautherie, Haehnel, Walter et al. (1987) estimates sensitivity in asymptomatic women, but this value (74 percent) is lower than the 90 percent found for screen-film mammography. Other thermography studies show very poor results, with sensitivities from 36 to 80 percent. It is not clear whether the interpreting physicians were properly blinded.

Xeromammography

Sensitivities and specificities of xeromammography are comparable with those of screen-film mammography in most studies, although specificities as low as 31.3 percent have been reported. Reported sensitivities range from 85.3 to 93.1 percent (Burhenne, Longley, and Burhenne, 1987; Cuttino, Yankaskas, and Hoskins, 1986; Marshall, Williams, and Smith, 1984; Wolfe, 1987). Radiation from xeromammography is reported to be approximately double that of screen-film mammography using a grid and approximately four times that of screen-film mammography without a grid (Conway, McCrohan, Rueter et al., 1990; Hendrick, 1990).

Digital Mammography

No evidence supports the use of digital mammography for screening or diagnostic examination of breast problems. Total-breast (18 cm x 24 cm or larger) digital image receptors are being developed (Yaffe, 1993). Smaller digital image receptors (approximately 5 cm x 5 cm) are now being used in stereotactically guided breast needle biopsy systems (Hendrick and Parker, 1992 and 1993; Karellas, Harris, and D'Orsi, 1990). Questions remain about the ability of digital image receptors to detect and characterize very small calcifications (Karssemeijer, Frieling, and Hendriks, 1993). Theoretical studies suggest that the sensitivity of digital mammography should equal or exceed the sensitivity of screen-film mammography for breast cancer (Yaffe, 1993). Clinical studies comparing digital and screen-film mammography are likely to be performed in the next few years (Shtern, 1992).

Acronyms and Abbreviations

• ABR

• American Board of Radiology

• ACR

• American College of Radiology

• AEC

• Automatic exposure control

• AHCPR

• Agency for Health Care Policy and Research

• AOBR

• American Osteopathic Board of Radiology

• BEIR

• Biological Effects of Ionizing Radiation

• BSE

• Breast self-examination

• CBE

• Clinical breast examination

• CC

• Craniocaudal

• cGy

• CentiGray

• CME

• Continuing Medical Education

• FDA

• Food and Drug Administration

• FN

• False negative

• FNAB

• Fine-needle aspiration biopsy

• FP

• False positive

• kVp

• Peak kilovoltage

• lp/mm

• Line pairs per millimeter

• MAP

• Mammography Accreditation Program

• mAs

• Milliampere second

• MLO

• Mediolateral oblique

• Mo

• Molybdenum

• MQSA

• Mammography Quality Standards Act

• PPV

• Positive predictive value

• TN

• True negative

• TP

• True positive

Glossary

• Note:

• The following source documents were used in developing these definitions: Coleman, Somkin, and Sung (1990); Dorland's Illustrated Medical Dictionary (1988); Gray, Bassett, Feig et al. (1992); Laurence Urdang Associates, Ltd. (1981); Love (1991); and Taber (1965).

Abnormal screening examination.: Mammography examination resulting in the recommendation of further imaging evaluation, short-interval followup, or biopsy.

Areola.: The pigmented ring of tissue that surrounds the nipple (plural: areolae or areolas).

Artifact.: Any unwanted or complicating structure visible in the image.

Automatic exposure control (AEC) systems.: Often referred to as phototimers; designed to automatically determine and provide the exposure needed to produce an adequate-density image by sampling the x-ray intensity after passage through the breast and image receptor.

Average glandular dose.: Calculated from values of entrance exposure in air, the x-ray beam quality (half-value layer), and compressed breast thickness; energy deposited per unit mass of glandular tissue (by far the most radiosensitive tissue in the breast) averaged over all the glandular tissue in the breast. Should be 6 mGy (0.6 rad) or less for a two-view screen-film examination of an average breast (see Dose).

Axilla.: The underarm area containing lymph nodes and channels, blood vessels, nerves, muscle, and fat; anterior border is the pectoralis major muscle and posterior border is the latissimus dorsi muscle (adjective: axillary).

Axillary tail.: Anatomical projection of breast tissue that extends into axilla (axillary tail of Spence).

Axillary tail view (AT).: Previously called Cleopatra view; used to demonstrate the entire axillary tail as well as the adjacent lateral aspect of the breast.

Beam quality assessment.: The measurement of half-value layer; describes the penetrating nature of an x-ray beam (see Half-value layer).

Benign.: A noncancerous condition that does not spread to other parts of the body.

Biopsy.: Removal of an entire abnormality (excisional biopsy) or a sampling or portion of an abnormality (core biopsy and incisional biopsy) for microscopic examination in order to diagnose a problem.

Breast carcinoma in situ.: Breast change in which malignant cells are localized and confined to breast ducts or lobules and may press against adjoining breast tissue but have not penetrated or spread beyond the breast. (Also called noninvasive breast cancer, noninfiltrating breast cancer.)

Breast conservation.: A surgical procedure for removing a cancerous tumor, lesion, or lump along with a rim of normal tissue around it. (Also called a lumpectomy.)

Breast self-examination (BSE).: Inspection and palpation of her breasts by the woman herself.

Bucky.: A component of the mammography x-ray unit that contains a moving grid, holds the x-ray film cassette, and supports the breast during imaging.

Calcifications.: See Microcalcifications.

Cancer.: A general term for more than 100 diseases characterized by abnormal and uncontrolled growth of cells.

Cassette.: A light-tight case for holding x-ray film, usually made of thin, low x-ray absorption polycarbonate material.

Cleavage view.: Used to visualize all of the medial tissue of the breast. (Also called valley view, double breast compression.)

Clinical breast examination (CBE).: A complete examination of the breasts and axilla with palpation by a health care professional, including examination of the breasts with the woman upright and supine.

Compression.: Involves pressing the breast between the compression device and the platform holding the film during mammography.

Compression device.: A clear plastic paddle, or plate, used to hold the breast stationary and eliminate blurring, to help separate structures within the breast, and to decrease the thickness of the breast tissue, minimizing the amount of radiation used and the amount of scattered radiation reaching the film.

Contact mammography.: Usual mammography, with the breast in direct contact with the Bucky (unlike magnification technique).

Contralateral.: Originating in or affecting the opposite side of the body.

Correlative breast examination.: Directed palpation of the breast performed by either the radiologic technologist or the interpreting physician to improve interpretation and ensure that a palpable abnormality is included on the film.

Craniocaudal (CC).: One of the two standard views used for mammography; the image receptor is placed caudad to (below) the breast and the vertical x-ray beam is directed from cranial to caudad (downward) through the breast.

Cyst.: A fluid-filled sac; may be felt on physical examination or depicted by mammography or ultrasonography.

Darkroom fog.: Added optical density on a film due to light leaks or safe lights in a darkroom; degrades image contrast and must be tested and eliminated to ensure image quality.

Dedicated mammography equipment.: X-ray systems designed specifically for breast imaging.

Densitometer.: An instrument that measures the degree of blackening or optical density of film.

Diagnostic mammography.: A radiologic examination used to evaluate a patient with a breast mass or breast masses, other breast signs or symptoms (spontaneous nipple discharge, skin changes, etc.), an abnormal or questionable screening mammogram, or special cases such as a history of breast cancer with breast conservation or augmented breasts.

Diaphanography.: A noninvasive breast imaging technique that uses visible or near-visible light in an attempt to visualize breast masses.

Dose.: The amount of energy deposited by ionizing radiation per unit mass of tissue.

Duct.: A channel for transporting fluid from the lobules (breast glands that produce milk) to the nipple.

Ductal carcinoma in situ.: A form of breast carcinoma in situ confined to the breast ducts; often reveals itself with microcalcification on mammography. (Also called noninvasive breast carcinoma or intraductal breast carcinoma.)

Exaggerated craniocaudal.: A view that depicts lesions in the outer (lateral) aspect of the breast, including much of the axillary tail.

Excessive biopsies.: Occur when the true positive biopsy rate (number of cancers detected/number of biopsies performed) is very low: too many biopsies are performed on benign findings or too few biopsies yield breast cancer.

Exposure.: The amount of x-ray irradiation, quantitated by measuring the amount of ionization in air caused by the radiation.

Fibroadenoma.: A benign breast condition common in young adult women in which the breast develops a solid lump, usually firm but movable in the breast. The lump is named for the proportions of glandular (adeno-) and fibrous (fibro-) tissue present.

Filtration.: A metal absorber placed in the path of the x-ray beam just after the x-ray tube to absorb very low energy x-rays and x-rays above a certain energy to produce an x-ray beam with a narrow energy range. Molybdenum is the most common metal for use as filtration in mammography.

Fine-needle aspiration biopsy (FNAB).: A diagnostic technique used to sample cells from breast lumps. Cells from lumps are aspirated with a thin needle, smeared on a glass slide, stained, and evaluated by a pathologist.

First-degree relative.: Mother, daughter, or sister.

Focal spot.: The area of the target or anode that is bombarded by electrons from the cathode to produce x-rays. The smaller the focal spot, the better the limiting spatial resolution of the x-ray system, especially in magnification mammography.

Fog.: Unwanted optical density added to a radiograph by action of the developer on the unexposed silver halide crystals or by light, radiation, or heat exposure during storage, handling, and processing.

Grid.: A set of thin, closely spaced lead strips used in mammography to reduce scattered radiation reaching the image receptor and improve image contrast; placed between the breast and the screen-film image receptor.

Half-value layer (HVL).: The thickness of a specified substance that reduces the exposure rate of a beam of radiation by one-half; measures beam quality and is usually expressed as millimeters of aluminum. The higher the HVL, the more penetrating the x-ray beam.

Image contrast.: The optical density difference between different areas on a radiograph, such as between an abnormality and surrounding tissue.

Image quality.: A combination of physical variables (e.g., contrast, limiting spatial resolution, and image noise) that contributes to the ability of a radiograph to portray diagnostic information.

Image receptor.: The device used to record the breast images.

Image sharpness.: How well the margins of linear structures, masses, and calcifications are depicted in the radiograph.

In situ.: Confined to site of origin, not having invaded adjoining tissues or metastasized to other parts of the body (e.g., intraductal).

Incisional biopsy.: A procedure in which the surgeon cuts into a suspicious area and removes a small sample (different from excisional biopsy or fine-needle aspiration).

Inspection.: The part of the complete breast examination in which the breasts are examined visually for asymmetry and skin changes.

Invasive breast cancer.: Disease in which breast cancer cells have penetrated surrounding breast tissue and can spread into distant organs.

Ipsilateral.: Originating in or affecting the same side of the body.

Kilovoltage, peak (kVp).: The maximum potential difference between the anode and the cathode in an x-ray tube. This setting is also the maximum energy of x-rays emitted by the x-ray tube in kiloelectronvolts.

Lateral view.: A 90° view performed medial to lateral or lateral to medial; used for triangulation with the craniocaudal and to demonstrate gravity-dependent calcifications.

Lateromedial.: A 90° view performed with the x-ray beam directed from the outer aspect of the breast to the inner aspect of the breast.

Lateromedial oblique (LMO).: Performed with the x-ray beam directed from the lower-outer to the upper-inner aspect of the breast; the exact reverse of the mediolateral oblique view; improves visualization of medial breast tissue. (Also called true reverse oblique.)

Lobe.: A portion of the breast that contains a complete unit for producing, transporting, and delivering milk.

Lobular carcinoma in situ (LCIS).: A high-risk condition in which multiple atypical cells fill and distend the lobules. Because it is a risk factor and not a direct precursor of invasive cancer, LCIS is considered a marker for increased risk of development of breast cancer in any location in either breast. (Also called lobular neoplasia.)

Localization.: Prebiopsy localization provides a method for biopsy of nonpalpable mammographic abnormalities; can be performed by needle placement alone, spot dye injection, or needle-hookwire methods.

Lymph nodes.: Kidney bean-shaped structures scattered along vessels of the lymphatic system seen in the axilla or sometimes in the breast itself; act as filters, collecting bacteria or cancer cells that may travel through the lymph system. (Also called lymph glands.)

Magnetic resonance imaging (MRI).: An imaging modality using a strong magnetic field and radiofrequency signals to produce multiplanar images of the body. Image contrast is based on the hydrogen concentration, molecular response to radiofrequency signals, and flow of structures within the part of the body being imaged.

Magnification view.: A technique for producing an enlarged image with greater detail of a small area of suspicious breast tissue.

Malignant.: Cancerous; a growth of cancer cells.

Mammary dysplasia.: Poorly structured tissue in the breast; not recommended terminology.

Mammogram.: An x-ray image of the breast recorded on film or paper.

Mammography.: An x-ray examination of the breast (see Screening mammography and Diagnostic mammography).

Mastectomy.: Surgical removal of all (modified radical, total, simple) or part (partial, segmental) of the breast and sometimes adjoining structures; usually done for breast cancer.

Medical audit.: Systematic collection and analysis of mammography results, comparing those results with outcomes data.

Medical physics.: The application of physics and related sciences to the clinical practice of medicine.

Mediolateral.: A 90° lateral view with the detector system placed lateral to the breast and the horizontal x-ray beam directed medial to lateral.

Mediolateral oblique (MLO).: One of the two standard views in mammography. The detector system (cassette holder assembly) is usually angled 30-60° from horizontal so that the cassette assembly is parallel to the pectoral muscle and the corner of the cassette holder fits comfortably into the axilla. The x-ray beam is directed from the superomedial to the inferolateral aspect of the breast.

Metastasis.: The spread of cancer from the place where it arises to another part of the body by lymphatic or blood vessels.

Microcalcifications.: Tiny white specks of calcium salts that can sometimes be seen on a mammogram. In clusters, they can be the only sign of ductal cancer in situ or early invasive cancer, or they can be associated with benign breast changes. (Also called calcifications.)

Milliampere (mA) setting.: The electron current passing from cathode to anode in an x-ray tube; also referred to as tube output. The number of x-rays per unit time emitted from the tube is linearly proportional to the mA setting.

Milliampere seconds (mAs).: The product of tube current (mA) and the exposure time (in seconds). For a fixed peak kilovoltage, total x-ray output is linearly proportional to the mAs setting.

90° lateral.: Most commonly used additional projection; used in conjunction with the standard views to triangulate the exact location of the lesions in the breast.

Nipple discharge.: Secretion of fluid from the nipple, either spontaneously or elicited from the nipple area. Nipple discharge (other than milk in a lactating woman) often results from benign breast changes or minor hormonal irregularities but, if spontaneous, needs to be checked by a health professional.

Nodularity.: General lumpiness of normal textured tissue consistency, often bilateral.

Nodule.: A discrete small lump as opposed to normal nodularity.

Off line.: The interpreting physician interprets films later in the day after the examinations are performed.

On line.: The interpreting physician is on site and interprets the films as they are performed.

Overall cancer detection rate.: The overall number of cancers detected per 1,000 patients examined by mammography.

Palpation.: Generally, examination by touch; the part of breast examination during which the breast tissue and structures are felt with the finger pads.

Phantom.: A test object that simulates some aspect of the anatomy of interest. A good breast phantom permits objective rather than subjective analysis and should be sensitive to small changes in mammographic image quality.

Position.: The orientation of the patient (upright, supine).

Positioning.: The maneuvers the radiologic technologist uses to place the breast in the desired position on the film for a specific mammographic view.

Processor.: An automated device that transports film at a constant speed by a system of rollers through developing, fixing, washing, and drying cycles.

Projection.: The direction of the central ray (e.g., mediolateral, craniocaudal) in an x-ray exam.

Provider.: Referring physician or other health care professional who refers women for mammography (e.g., family practice physician, nurse practitioner, physician's assistant).

Quality assurance.: A management tool that includes policies and systematic procedures designed to monitor and improve the performance of facility personnel, equipment, and systems; contributes to identification of corrective actions to be taken to remedy problems found as a result of investigation of the quality of care.

Quality control.: The routine monitoring of performance and functioning of x-ray imaging and processing equipment.

Radiopaque.: Not penetrable by x-rays or other forms of radiant energy; radiopaque areas appear light or white on the exposed film.

Relative risk.: The mortality rate in women who have the risk factor (a first-degree relative with breast cancer) divided by the mortality rate due to breast cancer in women who do not have the risk factor.

Repeat analysis.: Collection, evaluation, and recordkeeping of mammograms that have been reperformed to determine the reasons for errors on the x-ray image.

Roll.: A mammographic view used to separate superimposed breast tissues.

Safelight.: A filtered light source that produces visible light that will not fog exposed radiographic film excessively in a specified period of time.

Sanguineous.: Relating to blood.

Screen.: Microscopic phosphor crystals coated on a plastic support that emits visible light when exposed to x-irradiation, thereby creating a latent image on x-ray film.

Screen-film contact.: The proximity of the intensifying screen to the emulsion of the film. Intimate screen-film contact is essential for achieving a sharp image on the film.

Screen-film mammography.: Mammography performed with the high-detail intensifying screen (or screens) in close contact with the film.

Screening mammography.: X-ray examination of the breasts of asymptomatic women in an attempt to detect abnormal lesions of the breast when they are small, not palpable, and confined to the breast.

Self-referred.: A woman who refers herself for medical services and who does not have an identified referring physician or other health care provider.

Self-requesting.: A woman who refers herself for medical services but identifies a health care provider.

Sensitivity.: The probability of detecting a cancer when a cancer exists, otherwise defined as the fraction of all patients found to have breast cancer within 1 year of screening who were correctly diagnosed as being suspicious for breast cancer at the screening session.

Sensitometry.: A quantitative measurement of the response of film to exposure and photographic processing.

Serosanguineous.: Denoting an exudate or discharge composed of or containing serum and blood (hematest positive).

Serous.: Relating to the clear portion of a body fluid.

Spatial resolution.: The ability to image two separate objects and visually detect one from the other.

Specificity.: The probability of a normal mammogram report when no cancer exists, otherwise defined as the fraction of all patients found not to have breast cancer within 1 year of screening who were correctly identified as normal at the time of screening.

Specimen radiography.: The technique for examining a biopsy specimen by x-ray imaging.

Spot compression.: Allows for greater reduction in thickness of the localized area of interest and improved separation of breast tissues by the use of a small compression device; requires collimation to the area of interest. (Also called coned compression.)

Thermography.: A breast imaging technique that measures body heat at the skin surface to identify hot spots caused by inflammation or cancer.

Thermoluminescent dosimeter.: A radiation exposure measurement device using a chip or powder; absorbs radiation and when heated produces light proportional to the amount of radiation absorbed.

Transillumination.: A noninvasive breast imaging technique that uses visible or near-visible light in an attempt to visualize breast masses.

Ultrasonography.: The use of sonic energy (sound) to produce a pictorial representation of the internal structure of the breast. The image is produced by pulse-echo techniques, with detection and display of tissue interfaces rather than densities.

Unsharpness.: The inability of an x-ray imaging system to clearly define an edge on the final image. (Also called blur.)

View.: The image of the breast on the film resulting from projection of the x-ray beam and the breast-positioning maneuvers performed by the radiologic technologist; usually named according to the direction of the x-ray beam relative to the breast (e.g., mediolateral, craniocaudal).

Xeromammography.: X-ray imaging of the breast that uses (instead of x-ray film) a uniformly charged photoconductive plate held in a light-proof cassette.

Xeroradiography.: A form of x-ray imaging that records the image on paper rather than film, using the technique described under xeromammography.

X-rays.: Radiation that can, at low levels, be a diagnostic tool; used at extremely high levels, it can be used to treat cancer by destroying the cells (radiation therapy).

Contributors

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