Imaging features of Brucella-infected aneurysms: high prevalence of concurrent spondylitis and absence of ectopic gas.

AIM: Arterial involvement in brucellosis is an underrecognized disease. This study aimed to identify the distinctive imaging features of Brucella-infected aneurysms (BIA).

MATERIALS AND

METHODS

A retrospective cohort study was conducted at a tertiary referral hospital between January 2012 and November 2024, enrolling 26 patients with BIA (confirmed via serological examination and positive blood culture) and 22 common infected aneurysm controls without brucella. Diagnosis followed established consensus criteria. Clinical, laboratory, and computed tomography angiography (CTA) data were analyzed. Two radiologists independently assessed imaging features.

RESULTS

Patients with BIA exhibited lower mean leukocyte counts [6.82 ± 1.99 standard deviation (SD) versus 13.62 ± 12.74 (SD) × 109/L, P=0.010] and fewer positive blood cultures (15.4% versus 68.2%, P=0.001). CTA revealed no ectopic gas in BIA (0% versus 22.7% in controls, P=0.004) but a higher spondylitis prevalence (46.2% versus 18.2%, P=0.041). Other features, including saccular morphology, calcification (84.6% versus 77.3%), perianeurysmal findings, and infrarenal location (57.7% versus 72.7%), were comparable. A diagnostic strategy combining spondylitis and absent ectopic gas demonstrated high specificity (86.26%) and positive predictive value (80.00%) for BIA. This effect was even more pronounced when tuberculosis was excluded (specificity = 95.00%).

CONCLUSION

BIA shares key imaging features (e.g., saccular shape, perianeurysmal inflammation) with other infected aneurysms. However, the absence of ectopic gas and the high prevalence of concurrent spondylitis are distinctive for BIA. These findings support early Brucella-specific testing to guide timely antimicrobial therapy in suspected cases.