Refereed journal article or data article (A1)
Effect of Attenuation Correction on Regional Quantification Between PET/MR and PET/CT: A Multicenter Study Using a 3-Dimensional Brain Phantom
List of Authors: Teuho J, Johansson J, Linden J, Hansen AE, Holm S, Keller SH, Delso G, Veit-Haibach P, Magota K, Saunavaara V, Tolvanen T, Teras M, Iida H
Publisher: SOC NUCLEAR MEDICINE INC
Publication year: 2016
Journal: Journal of Nuclear Medicine
Journal name in source: JOURNAL OF NUCLEAR MEDICINE
Journal acronym: J NUCL MED
Volume number: 57
Issue number: 5
Start page: 818
End page: 824
Number of pages: 7
ISSN: 0161-5505
DOI: http://dx.doi.org/10.2967/jnumed.115.166165
A spatial bias in brain PET/MR exists compared with PET/CT, because of MR-based attenuation correction. We performed an evaluation among 4 institutions, 3 PET/MR systems, and 4 PET/CT systems using an anthropomorphic brain phantom, hypothesizing that the spatial bias would be minimized with CT-based attenuation correction (CTAC). Methods: The evaluation protocol was similar to the quantification of changes in neurologic PET studies. Regional analysis was conducted on 8 anatomic volumes of interest (VOls) in gray matter on count-normalized, resolution-matched, coregistered data. On PET/MR systems, CTAC was applied as the reference method for attenuation correction. Results: With CTAC, visual and quantitative differences between PET/MR and PET/CT systems were minimized. Intersystem variation between institutions was +3.42% to -3.29% in all VOls for PET/CT and +2.15% to -4.50% in all VOls for PET/MR. PET/MR systems differed by +2.34% to -2.21%, +2.04% to -2.08%, and -1.77% to -5.37% when compared with a PET/CT system at each institution, and these differences were not significant (P >= 0.05). Conclusion: Visual and quantitative differences between PET/MR and PET/CT systems can be minimized by an accurate and standardized method of attenuation correction. If a method similar to CTAC can be implemented for brain PET/MRI, there is no reason why PET/MR should not perform as well as PET/CT.