18F-FDG PET-CT Imaging Characteristics of Penetrating Aortic Ulcers

Abstract Purpose This study analyzed 18F-FDG PET-CT imaging characteristics of penetrating aortic ulcers (PAUs) and evaluating its feasibility and diagnostic efficacy in clinical assessment. Methods In this retrospective study, patients diagnosed with PAUs by CTA between August 2018 and July 2023 who underwent PET-CT within 180 days of CTA were enrolled as the ulcer cohort. Age-, sex-, and hypertension-matched controls (1:1 ratio) served as controls. Statistical analysis was performed on clinical and imaging parameters. Results Thirty-seven PAU patients and thirty-seven matched controls were included. Only two PAU cases (5.41%) showed positive 18F-FDG uptake (SUVmax > 2.5). No statistically significant differences were found in SUVmax or target-to-background ratio (TBR) between groups. While no significant correlations were found between aortic diameter or PAU width and metabolic parameters, Pearson correlation analysis found that PAU had significant positive correlations with both SUVmax (r = 0.437, p = 0.007) and TBR (r = 0.461, p = 0.005); and spearman correlation analysis demonstrated that the PAU depth is positively correlated with TBR (ρ = 0.386, p = 0.018). The positive correlation between PAU depth and TBR remains statistically significant (r = 0.354, p = 0.037) after excluding the two PET-CT-positive outliers. Conclusions Although PAUs demonstrate low rates of hypermetabolism on 18F-FDG PET-CT imaging, ulcer depth exhibits significant positive correlations with TBR values, suggesting 18F-FDG PET-CT may serve as a complementary imaging modality for PAU patients with high-risk features for disease progression.