Display Settings:

Items per page
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information

Results: 20

1.

FIGURE 15. Diverticular disease at CTC – 2D versus 3D evaluation. From: CT Colonography: Pitfalls in Interpretation.

2D (A) and 3D (B) CTC images show innumerable sigmoid diverticula. Exclusion of superimposed polyps is a much simpler task on the 3D endoluminal view.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
2.

FIGURE 14. Sigmoid diverticular disease at CTC. From: CT Colonography: Pitfalls in Interpretation.

Supine 2D CTC images (A and B) show wall thickening and luminal narrowing related to advanced sigmoid diverticulosis. This appearance can make it challenging to exclude superimposed neoplastic pathology. 3D evaluation can be very valuable in this setting

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
3.

FIGURE 18. Submucosal venous bleb simulating a flat polyp at CTC. From: CT Colonography: Pitfalls in Interpretation.

3D endoluminal CTC image (A) shows a flat plaque-like lesion adjacent to a colonic fold, which appeared to be soft tissue attenuation on 2D correlation (not shown). At subsequent OC (B), however, the lesion proved to be a submucosal venous bleb.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
4.

FIGURE 8. Beam-hardening artifact from bilateral total hip arthroplasties. From: CT Colonography: Pitfalls in Interpretation.

2D CTC images through the pelvis (A and B) show marked beam-hardening artifact, which appears more severe on the soft tissue windows. Streak artifact across the rectum is also apparent on the 3D endoluminal view (C).

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
5.

FIGURE 13. Persistently thickened fold at CTC. From: CT Colonography: Pitfalls in Interpretation.

Prone (A and B) and supine (C and D) CTC images show a thickened sigmoid fold that appears almost mass-like at 2D. The smooth thickening appears to be related to a point of slight twisting or torsion. Note the fat extending into the fold on B, which excludes an infiltrating cancer.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
6.

FIGURE 4. Confirmation of polyp on poorly-distended colonic segment. From: CT Colonography: Pitfalls in Interpretation.

Supine 2D CTC images (A and B) show long-segment collapse of the sigmoid colon, largely obscuring a 15-mm polyp (arrows), which is easily identified on the alternate position (C and D). This proved to be a tubular adenoma after resection at OC (E).
(From reference 5, with permission)

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
7.

FIGURE 5. Right lateral decubitus position for salvaging adequate luminal distention. From: CT Colonography: Pitfalls in Interpretation.

Supine 2D CTC image (A) shows long-segment collapse of the sigmoid colon, related to diverticular disease. The prone view had a similar appearance (not shown). Luminal distention on the decubitus view (C), however, was excellent and allowed for a diagnostic examination.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
8.

FIGURE 7. Artifact related to actively flowing luminal fluid (the “dense waterfall” sign). From: CT Colonography: Pitfalls in Interpretation.

Prone 2D CTC image (A) shows multiple arciform streaks off the air-fluid level in the descending colon, which is caused by the intra-scan flow of fluid. Note the lack of motion or artifacts elsewhere on the image. The artifacts are also evident on the 3D endoluminal view (B).

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
9.

FIGURE 2. Tagged stool mimicking a flat polyp on 3D. From: CT Colonography: Pitfalls in Interpretation.

3D endoluminal CTC image (A) shows an elongated flat lesion on a colonic fold. However, both 3D with translucency rendering (B) and coronal 2D correlation (C) show dense internal contrast tagging, excluding a flat polyp. Care must be taken in such cases to ensure a true flat soft tissue polyp does not lie deep to the contrast.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
10.

FIGURE 10. Large contrast-coated tubulovillous adenoma involving the ileocecal valve. From: CT Colonography: Pitfalls in Interpretation.

Transverse 2D CTC images with polyp (A) and soft tissue (B) window settings show a multi-lobulated mass occupying the expected location of the ileocecal valve. Note the distinct contrast etching that outlines the surfaces of the lesion. 3D endoluminal (C) and OC (D) images show the mass, which involved the ileocecal valve.
(From reference 5, with permission)

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
11.

FIGURE 12. 2D versus 3D CTC measurement of an elongated polyp. From: CT Colonography: Pitfalls in Interpretation.

3D endoluminal CTC images (A–C) show an elongated polyp with the transverse (A), sagittal (B), and coronal (C) 2D planes as colored lines through the polyp, corresponding to the 2D transverse (D), sagittal (E), and coronal (F) images (arrows). Even with the “optimized” coronal 2D measurement (C and F), the polyp is significantly undersized, whereas the 3D measurement (G) corresponds to the actual long axis of the polyp, and correlated best with OC (H).
(From reference 5, with permission)

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
12.

FIGURE 6. Decubitus position in morbidly obese individual. From: CT Colonography: Pitfalls in Interpretation.

Supine 2D CTC image (A) in a 350-lb patient shows complete collapse of the sigmoid colon. An equilibrium pressure of 20 mm Hg was utilized for the automated CO2. Decubitus positioning (B) and increase to 25 mm Hg resulted in good luminal distention of this segment, as shown by frontal (C) and lateral (D) 3D colon maps.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
13.

FIGURE 16. Nondiagnostic luminal distention related to a diverticular stricture. From: CT Colonography: Pitfalls in Interpretation.

Supine (A and B) and decubitus (C) CTC images show an area of persistent wall thickening and luminal narrowing (arrowheads) in the setting of advanced sigmoid diverticular disease. The prone images had a similar appearance (not shown). The 3D colon map shows the site of this persistent stenosis (arrow and red dot), which proved to be a diverticular stricture.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
14.

FIGURE 9. Ultra-low dose CTC using newer iterative reconstruction algorithms. From: CT Colonography: Pitfalls in Interpretation.

3D endoluminal CTC image (A) from ultra-low-dose scan (0.3 mSv) reconstructed with traditional filtered back projection (FBP) technique shows significant image noise. The rectal catheter is visible but the rectal polyp is largely obscured. When the same CT image data are reconstructed with a newer iterative reconstruction algorithm (B), the polyp (arrow) becomes much more conspicuous.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
15.

FIGURE 19. Extrinsic impression related to an adjacent small bowel loop. From: CT Colonography: Pitfalls in Interpretation.

Coronal 2D CTC images (A and B) show a focal soft tissue “mass” (arrowhead) involving the transverse colon. Transverse 2D image (C), however, shows the small bowel loop (arrow) extending across the adjacent colon. At 3D (D), the preservation of the overlying colonic fold is a sign that the lesion is caused by extrinsic impression.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
16.

FIGURE 17. Large cecal carpet lesion (laterally spreading tumor). From: CT Colonography: Pitfalls in Interpretation.

Supine transverse 2D (A and B) and 3D endoluminal (C) CTC images show a large flat soft tissue mass (arrowheads) opposite the ileocecal valve (arrow) that has a somewhat lobulated appearance and results in fold distortion on 3D. Note the contrast coating portions of the lesion on B. This carpet lesion was confirmed at same-day optical colonoscopy (D) and proved to be a tubulovillous adenoma. Most non-flat lesions of this large size would be malignant.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
17.

FIGURE 3. Flat lesion obscured by densely opacified fluid on soft tissue windows. From: CT Colonography: Pitfalls in Interpretation.

Prone transverse 2D CTC image with polyp windowing (A) shows a flat cecal polyp (arrowhead), which is submerged under opacified fluid but is nonetheless detectable. On the soft tissue window setting (B), however, the lesion is obscured by the dense surrounding fluid. This windowing phenomenon is also the reason why 2D lesion measurement must take place on the wider polyp window setting. 3D endoluminal CTC image (C) in the supine position shows the flat lesion outlined by air. The lesion was confirmed at subsequent OC (D) and proved to be a tubulovillous adenoma.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
18.

FIGURE 1. Tagged adherent stool simulating a sessile polyp on 3D. From: CT Colonography: Pitfalls in Interpretation.

3D endoluminal CTC image (A) shows a polypoid lesion, as well as smaller adjacent diminutive foci. Both 3D translucency rendering (B) and 2D correlation (C) show dense internal contrast tagging, easily excluding a polyp. Note that the adherent stool is nondependent on this prone 2D view, which could simulate a true lesion if untagged.
(From Pickhardt PJ, Kim DH. Potential pitfalls at CTC Interpretation, In: CT colonography: principles and practice of virtual colonoscopy. Philadelphia: Saunders; 2010, with permission)

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
19.

FIGURE 11. Apparent decrease in polyp size on soft tissue window setting. From: CT Colonography: Pitfalls in Interpretation.

Supine transverse 2D CTC image (A) with polyp window setting (2000/0) shows a 10-mm sessile polyp in the cecum (calipers). On a soft tissue window setting (B, 350/40), the polyp appears to decrease in size to less than 10-mm. Polyp measurement on soft tissue windows could lead to inappropriate management. On the prone 2D CTC images (C and D), the polyp (arrow) is submerged under densely opacified fluid, which further decreases the apparent polyp size. Note how the lesion is barely perceptible on the soft tissue window setting (D).
(From reference 5, with permission)

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.
20.

FIGURE 20. Interpretive pitfalls related to the anorectal, ileocecal valve, and appendiceal regions within the same case. From: CT Colonography: Pitfalls in Interpretation.

The 3D colon map shows three bookmarks (red dots) denoting focal findings in the regions of the anorectum, ileocecal valve, and the appendiceal orifice. Sagittal 2D (B and C) and 3D endoluminal (D) CTC images show an unusual 3–4 cm soft tissue mass extending up from the anorectal region. Note the mass effect upon the lesion from the adjacent balloon on the rectal catheter. The mass was confirmed at OC (E) but endoscopic biopsies were inconclusive. After transanal excision, a hemorrhoid with organizing thrombosis was confirmed. Focal abnormalities (arrows) were also noted at the ileocecal valve (F and G) and the appendiceal orifice (F and H). At OC, an inflammatory polyp on the ileocecal valve and a small inverted appendiceal stump were confirmed.

Perry J. Pickhardt, et al. Radiol Clin North Am. ;51(1):69-88.

Display Settings:

Items per page

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...
Write to the Help Desk