Abstract 731: Positive Uptake of F-18 Fluorodeoxyglucose in Acute Aortic Dissection: A Determinant of Unfavorable Outcome
Background: The advent of combining positron emission tomography (PET) and computed tomography (CT) acquisition (PET/CT) enables visualized vascular inflammation by using F-18 fluorodeoxyglucose (18F-FDG). Several studies identified increased 18F-FDG uptake in carotid artery plaques and aorta. However, clinical assessment of acute aortic dissection (AAD) by PET/CT remains largely unknown. This study aims to explore the clinical availability of 18F-FDG uptake for the prediction of short- and mid-term outcomes in medically controlled AAD patients using PET/CT.
Methods: A total of 28 medically treated AAD (2 Stanford Type A, and 26 type B, aged 69.5±11.6) patients were enrolled in this study. All patients were examined by enhanced CT for diagnosing of AAD and serial imaging studies during the follow-up. PET/CT images were acquired 50 and 100 minutes after 18F-FDG injection in all patients in the acute phase.
Results: Of the 28 patients, 8 who had unfavorable outcome due to death from rupture (n = 2), surgical repair (n = 4) and progression of dissection (n = 2) were classified into unfavorable AAD group. The remaining 20 patients were classified to favorable AAD group. Maximum dissection diameter in unfavorable AAD group was significantly greater than in favorable AAD group (P = 0.0207). 18F-FDG standard uptake volume (SUV)max and SUVmean of unfavorable AAD at maximum aortic dissection site were significantly greater than those of favorable AAD in 50-minute images (all P < 0.01). A stepwise forward selection procedure demonstrated that 18F-FDG SUVmean of 50-minute images at maximum aortic dissection site significantly and independently affected unfavorable outcome of AAD (P = 0.0171 Odds ratio, 7.72: 95% confidence interval, 1.44– 41.4). The SUVmean >3.029 had a significant predictive power with sensitivity, 75.0% specificity, 70.0% positive predictive value, 50.0% negative predictive value, 87.5% accuracy, 71.4%
Conclusion: Greater uptake of 18F-FDG in AAD was significantly associated with an increased risk for rupture and progression. Stratification of AAD patients corresponding to PET/CT evaluation may be helpful in predicting short- and mid-term outcomes of AAD and for undertaking timely surgical interventions.