Quantitative Evaluation of Atlas-based Attenuation Correction for Brain PET in an Integrated Time-of-Flight PET/MR Imaging System

Jaewon Yang; Yiqiang Jian; Nathaniel Jenkins; Spencer C Behr; Thomas A Hope; Peder E Z Larson; Daniel Vigneron; Youngho Seo

doi:10.1148/radiol.2017161603

Quantitative Evaluation of Atlas-based Attenuation Correction for Brain PET in an Integrated Time-of-Flight PET/MR Imaging System

Radiology. 2017 Jul;284(1):169-179. doi: 10.1148/radiol.2017161603. Epub 2017 Feb 23.

Authors

Jaewon Yang¹, Yiqiang Jian¹, Nathaniel Jenkins¹, Spencer C Behr¹, Thomas A Hope¹, Peder E Z Larson¹, Daniel Vigneron¹, Youngho Seo¹

Affiliation

¹ From the Department of Radiology and Biomedical Imaging, UCSF Physics Research Laboratory, University of California, San Francisco, 185 Berry St, Suite 350, San Francisco, CA 94143-0946 (J.Y., N.J., S.C.B., T.A.H., P.E.Z.L., D.V., Y.S.); GE Healthcare, Waukesha, Wis (Y.J.); and Department of Radiology, San Francisco VA Medical Center, San Francisco, Calif (T.A.H.).

PMID: 28234560
DOI: 10.1148/radiol.2017161603

Abstract

Purpose To assess the patient-dependent accuracy of atlas-based attenuation correction (ATAC) for brain positron emission tomography (PET) in an integrated time-of-flight (TOF) PET/magnetic resonance (MR) imaging system. Materials and Methods Thirty recruited patients provided informed consent in this institutional review board-approved study. All patients underwent whole-body fluorodeoxyglucose PET/computed tomography (CT) followed by TOF PET/MR imaging. With use of TOF PET data, PET images were reconstructed with four different attenuation correction (AC) methods: PET with patient CT-based AC (CTAC), PET with ATAC (air and bone from an atlas), PET with ATAC_patientBone (air and tissue from the atlas with patient bone), and PET with ATAC_boneless (air and tissue from the atlas without bone). For quantitative evaluation, PET mean activity concentration values were measured in 14 1-mL volumes of interest (VOIs) distributed throughout the brain and statistical significance was tested with a paired t test. Results The mean overall difference (±standard deviation) of PET with ATAC compared with PET with CTAC was -0.69 kBq/mL ± 0.60 (-4.0% ± 3.2) (P < .001). The results were patient dependent (range, -9.3% to 0.57%) and VOI dependent (range, -5.9 to -2.2). In addition, when bone was not included for AC, the overall difference of PET with ATAC_boneless (-9.4% ± 3.7) was significantly worse than that of PET with ATAC (-4.0% ± 3.2) (P < .001). Finally, when patient bone was used for AC instead of atlas bone, the overall difference of PET with ATAC_patientBone (-1.5% ± 1.5) improved over that of PET with ATAC (-4.0% ± 3.2) (P < .001). Conclusion ATAC in PET/MR imaging achieves similar quantification accuracy to that from CTAC by means of atlas-based bone compensation. However, patient-specific anatomic differences from the atlas causes bone attenuation differences and misclassified sinuses, which result in patient-dependent performance variation of ATAC. ^© RSNA, 2017 Online supplemental material is available for this article.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Brain / diagnostic imaging*
Brain Mapping / methods*
Female
Fluorodeoxyglucose F18
Humans
Image Processing, Computer-Assisted
Magnetic Resonance Imaging / instrumentation*
Male
Middle Aged
Multimodal Imaging / instrumentation*
Positron-Emission Tomography / instrumentation*
Radiopharmaceuticals
Sensitivity and Specificity

Substances

Radiopharmaceuticals
Fluorodeoxyglucose F18