¹⁸F-FDG uptake as a predictive factor for progressive aortic enlargement in aortic dissection

Area of Science:

• Cardiovascular Imaging
• Nuclear Medicine
• Aortic Diseases

Background:

• Progressive aortic enlargement (PAE) is a significant complication in patients with medically treated aortic dissection (AD).
• Currently, reliable predictors for PAE in this patient group are lacking.
• ¹⁸F-FDG PET/CT offers a potential imaging modality for risk stratification.

Purpose of the Study:

• To assess the utility of ¹⁸F-FDG PET/CT in predicting PAE in patients with medically treated AD.
• To determine if ¹⁸F-FDG uptake in the dissected aortic wall correlates with future aortic enlargement.

Main Methods:

• Sixteen patients with AD receiving optimal medical therapy were included.
• ¹⁸F-FDG PET/CT scans were performed in the subacute phase post-AD onset.
• Target-to-background ratio (TBR) was calculated by comparing SUVmax in the dissected aorta to blood pool SUV.

Main Results:

• Four out of 16 patients developed PAE (defined as >10 mm/year) during a median 24-month follow-up.
• Patients with PAE exhibited significantly higher TBR values compared to those without PAE (2.44 ± 0.56 vs. 1.87 ± 0.33, P=0.025).
• The TBR demonstrated good predictive performance (AUC=0.82) with a threshold of 2.34 yielding 75% sensitivity and 92% specificity for PAE.

Conclusions:

• Elevated ¹⁸F-FDG uptake, indicated by higher TBR in the dissected aortic wall, is linked to an increased risk of PAE in medically treated AD patients.
• TBR derived from ¹⁸F-FDG PET/CT is a valuable tool for predicting PAE, offering good specificity and negative predictive value.