Molecular Imaging of Abdominal Aortic Aneurysms with Positron Emission Tomography: A Systematic Review

Previous studies on the relationship between positron emission tomography (PET) images and abdominal aortic aneurysm (AAA) progression have shown contradictory results, and the objective of this study was to systematically review the role of PET in predicting AAA prognosis.PubMed, Embase, and Web of Science were searched for studies evaluating the correlation between PET imaging results and AAA growth, repair, or rupture.Two authors independently performed the study search, data extraction, and quality assessment following a standard method.Of the 11 studies included in this review, nine used 18F-fluorodeoxyglucose (18F-FDG) PET and computed tomography (CT) imaging, whereas the remaining two used 18F-sodium fluoride (18F-NaF) PET/CT and 18F-FDG PET/magnetic resonance imaging (MRI). Findings from the 18F-FDG PET/CT studies were contradictory. Six studies found no significant association or correlation, and two studies found a significant negative correlation between 18F-FDG uptake and AAA expansion. Additionally, one study found that the 18F-FDG uptake was statistically positively related to the expansion rate in a specific AAA subgroup whose AAAs expanded significantly. Two studies suggested that increased 18F-FDG uptake was significantly associated with AAA repair, while the other studies either found no association between 18F-FDG uptake and AAA rupture or repair or failed to report the occurrence of clinical events. One PET/CT study that used 18F-NaF as a tracer showed that an increased tracer uptake was significantly associated with AAA growth and clinical events. Finally, the 18F-FDG PET/MRI study indicated that 18F-FDG uptake was not significantly correlated with AAA expansion.A definitive role for 18F-FDG PET imaging for AAA prognosis awaits further investigation, and new PET tracers such as 18F-NaF have the potential to be a promising method for predicting AAA clinical outcomes.