%0 Journal Article %A Yasushi Kobayashi %A Kenji Ishii %A Keiichi Oda %A Tadashi Nariai %A Youji Tanaka %A Kiichi Ishiwata %A Fujio Numano %T Aortic Wall Inflammation Due to Takayasu Arteritis Imaged with 18F-FDG PET Coregistered with Enhanced CT %D 2005 %J Journal of Nuclear Medicine %P 917-922 %V 46 %N 6 %X The purpose of this study was to evaluate the ability of 18F-FDG PET to identify aortitis and to localize and follow disease activity in patients with Takayasu arteritis. The value of using 18F-FDG PET coregistered with enhanced CT in determining vascular lesion sites and inflammatory activity was assessed. Methods: Takayasu arteritis was diagnosed according to the predefined criteria. Eleven patients with Takayasu arteritis in the active stage, 3 patients with Takayasu arteritis in the inactive stage, and 6 healthy subjects underwent 18F-FDG PET coregistered with enhanced CT and the inflammatory vascular lesion was evaluated by using the standardized uptake value (SUV) of 18F-FDG accumulation as an index. Two patients with active disease were analyzed by sequential 18F-FDG PET scans during treatment. Results: The 18F-FDG PET revealed intense 18F-FDG accumulation (SUV ≥ 2.7) in the vasculature of 2 of the 11 cases in the active stage of Takayasu arteritis. The other 9 patients in the active stage revealed weak 18F-FDG accumulation (2.3 ≥ SUV ≥ 1.2). No significant 18F-FDG accumulation was observed in the patients with inactive disease (SUV ≤ 1.2) and 6 control healthy subjects (SUV < 1.3). Given the cutoff SUV is 1.3, the sensitivity of 18F-FDG PET analysis of Takayasu arteritis is 90.9% and the specificity is 88.8%. 18F-FDG PET coregistered with enhanced CT localized 18F-FDG accumulation in the aortic wall in the patients with Takayasu arteritis who had weak 18F-FDG accumulation that could not otherwise be identified anatomically. Finally, 18F-FDG accumulation resolved with therapy in 2 active cases. The disappearance of 18F-FDG accumulation did not coincide with the level of general inflammatory markers. Conclusion: The 18F-FDG PET images coregistered with enhanced CT images showed the distribution and inflammatory activity in the aorta, its branches, and the pulmonary artery in patients with active Takayasu arteritis, even those who had weak 18F-FDG accumulation. The intensity of accumulation decreased in response to therapy. %U https://jnm.snmjournals.org/content/jnumed/46/6/917.full.pdf