(18)Fluorodeoxyglucose positron emission tomography imaging of atherosclerotic plaque inflammation is highly reproducible: implications for atherosclerosis therapy trials.
OBJECTIVE
This study tested the near-term reproducibility of (18)fluorodeoxyglucose positron emission tomography (FDG-PET) imaging of atherosclerosis.


BACKGROUND
It is known that FDG-PET can measure inflammation within the aorta, carotid, and vertebral arteries with histologic validation in humans and animal models of disease. By tracking changes in inflammation over time, PET could be used as a surrogate marker of antiatheroma drug efficacy. However, the short-term variability and reproducibility of the technique are unknown.


METHODS
We imaged the carotid arteries and aorta in 11 subjects with FDG-PET/computed tomography twice, 14 days apart. We assessed interobserver and intraobserver agreement and interscan variability.


RESULTS
Interscan plaque FDG variability over 2 weeks was very low; intraclass correlation coefficients (ICC) ranged between 0.79 and 0.92. Interobserver agreement was high across all territories imaged except aortic arch (ICC values from 0.90 to 0.97, arch 0.71). Intraobserver agreement was high, with ICC values between 0.93 and 0.98.


CONCLUSIONS
Spontaneous change in plaque FDG uptake is low over 2 weeks, with favorable inter- and intraobserver agreement. Power calculations suggest that drug studies using FDG-PET imaging would require few subjects compared with other imaging modalities. This study strengthens the case for FDG-PET as a noninvasive plaque imaging technique.
Rudd
James H F
JH
Imaging Science Laboratories, Mount Sinai School of Medicine, New York, New York, USA. jhfr2@cam.acuk
Myers
Kelly S
KS
Bansilal
Sameer
S
Machac
Josef
J
Rafique
Ash
A
Farkouh
Michael
M
Fuster
Valentin
V
Fayad
Zahi A
ZA
D000368:Aged; D001018:Aortic Diseases / Q000000981:diagnostic imaging*; D050197:Atherosclerosis / Q000000981:diagnostic imaging*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging*; D003925:Diabetic Angiopathies / Q000000981:diagnostic imaging; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007249:Inflammation / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18