Effects of coverage extent and slice skipping on mean and maximum arterial 18F-FDG uptake ratios in patients with carotid plaque.
OBJECTIVE
To investigate the effects of variable measurement methods on mean and maximum SUV ratios of 18F-FDG uptake in carotid arteries.


METHODS
18F-FDG PET/CT images of 74 subjects with carotid plaque were analyzed for mean and maximum target-to-background ratio (TBR) of uptake. Agreement was analyzed between TBR scores obtained using different vessel coverage and slice skipping.


RESULTS
Mean TBR was increased by extending coverage from common carotid artery (CCA; 1.25) to carotid artery (CA; 1.33) and inclusion of ascending aorta (CA/AA; 1.34). Maximum TBR was increased from 1.47 to 1.54 and 1.61 by respective extensions. Both mean and maximum TBR were closely correlated between vessels. ICC and Kappa statistics revealed near perfect agreement between TBR obtained using every 2 or 3 segments and that without sipping. Bland-Altman plots showed bias by slice skipping to remain small, particularly for mean TBR. Finally, high correlations were displayed between mean and maximum TBR.


CONCLUSIONS
Analysis of mean and maximum arterial 18F-FDG uptake in patients with carotid plaque is likely to benefit from extending coverage to segments above and below the CCA. The extra burden of measurement, in turn, can be lightened by skipping up to every 2 of 3 slices without compromising accuracy of results.
Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul, 135-710, Korea.
Tae-Soo
TS
Noh
Jang
J
Yoo
Se Won
SW
Kim
Eun Jeong
EJ
Lee
Joon Young
JY
Choi
Byung-Tae
BT
Kim
Kyung-Han
KH
Lee
D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000378:metabolism*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed
D019788:Fluorodeoxyglucose F18