Evaluation of disease activity using F-18 FDG PET-CT in patients with Takayasu arteritis.
OBJECTIVE
To evaluate the usefulness of F-18 fluoro-fluorodeoxygulose positron emission tomography computed tomography (F-18 FDG PET-CT) in detecting clinically defined active disease in patients with Takayasu arteritis.


METHODS
F-18 FDG PET-CT was performed in 32 patients with Takayasu arteritis. Disease activity was assessed clinically by the National Institutes of Health (NIH) criteria. In 10 of the 32 patients, F-18 FDG PET-CT was performed while the patients were taking immunosuppressive drugs. Two nuclear physicians visually assessed the degree of F-18 FDG uptake in the walls of the aorta, its major branches and the pulmonary artery using a 4-point scale from grade 0 to III. F-18 FDG uptake greater than grade I in the thoracic aorta or greater than grade 0 in other areas were interpreted as active vasculitic lesions.


RESULTS
Ten patients had active lesions on F-18 FDG PET-CT. According to the NIH criteria, 9 patients had active disease and 23 had inactive disease. Compared with disease activity assessed by the NIH criteria, F-18 FDG PET-CT had a sensitivity of 78% and a specificity of 87%. The erythrocyte sedimentation rate and CRP levels were significantly higher in F-18 FDG PET-CT-positive than in F-18 FDG PET-CT-negative patients. There was no significant difference in the proportion of positive PET scans according to the use of glucocorticoids.


CONCLUSIONS
The sensitivity of F-18 FDG PET-CT for detecting active disease was higher in patients with higher erythrocyte sedimentation rate values. Although the specificity of F-18 FDG PET-CT was high, owing to the low sensitivity of the NIH criteria in detecting active disease, further studies are needed.
Division of Rheumatology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
Seung Geun
SG
Lee
Jin-Sook
JS
Ryu
Hye Ok
HO
Kim
Ji Seon
JS
Oh
Yong Gil
YG
Kim
Chang-Keun
CK
Lee
Bin
B
Yoo
D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D013625:Takayasu Arteritis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D014055:Tomography, Emission-Computed
D005938:Glucocorticoids; D019788:Fluorodeoxyglucose F18