RT Journal Article SR Electronic T1 Imaging of Acute and Chronic Aortic Dissection by 18F-FDG PET/CT JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 686 OP 691 DO 10.2967/jnumed.109.072298 VO 51 IS 5 A1 Reeps, Christian A1 Pelisek, Jaroslav A1 Bundschuh, Ralph A. A1 Gurdan, Manuela A1 Zimmermann, Alexander A1 Ockert, Stefan A1 Dobritz, Martin A1 Eckstein, Hans-Henning A1 Essler, Markus YR 2010 UL http://jnm.snmjournals.org/content/51/5/686.abstract AB By conventional imaging modalities, the discrimination between acute and chronic aortic dissection (AD) for surgical risk evaluation is not possible. However, acute and chronic stable AD potentially may be distinguished by detection of reparatory hypermetabolism in the lacerated aortic wall of acute AD using 18F-FDG PET/CT. In this study, we analyzed the 18F-FDG uptake in the aortic wall of acute and chronic stable AD. Methods: Eighteen patients with acute (n = 9), symptomatic progressive (n = 2), or known chronic stable (n = 7) type B AD underwent 18F-FDG PET/CT. Images were analyzed qualitatively and quantitatively considering 18F-FDG uptake patterns and the standardized uptake values (SUVs) of the aortic wall, dissection membrane, and luminal 18F-FDG activity. The SUV ratio (maximum SUV in the aorta divided by mean SUV in the blood pool) was calculated to relativize individual luminal 18F-FDG spillover effects. Results: In contrast to chronic stable AD, all acute or acute progressive AD showed accentuated 18F-FDG uptake at the injured aortic wall or dissection membrane. The maximum SUV of the dissection membrane or aortic wall was significantly higher (P = 0.02) in acute AD than in chronic stable AD. Thereby, SUV varied from 3.03 to 4.64 (average maximum SUV, 3.84 ± 0.51) for the dissection membrane and from 2.22 to 4.60 (average maximum SUV, 2.94 ± 0.81) for the aortic wall, with false-negative and false-positive outliers. The discrimination between acute and stable AD was improved significantly (P < 0.001), and false-positive or -negative outliers were eliminated, using the SUV ratio method. Conclusion: Our results indicate that 18F-FDG PET/CT might be useful in differentiation of acute from chronic AD in clinically unclear cases. However, larger studies are needed to confirm our preliminary results.