CT angiographic imaging characteristics of thoracic idiopathic aortitis

Idiopathic aortitis (IA) is characterized by giant cell or lymphoplasmacytic inflammation of aorta without a secondary cause.

We undertook a retrospective case-control study to identify characteristic CT angiographic findings in these patients and to correlate them with known atherosclerotic risk factors.

IA cases and controls with noninflammatory aneurysm (control group I) and patients with secondary aortitis (control group II) were identified with a pathology database. Preoperative CT angiographic images of thoracic aorta were reviewed. Diameter of thoracic aorta, wall thickness, and calcification were measured at various sites. Traditional atherosclerotic risk factors were identified from case records and included hypertension, hyperlipidemia, diabetes mellitus, and smoking.

Twenty-two idiopathic aortitis cases were compared with 18 patients in control group I and 16 patients in control group II. No differences were found in prevalence of hypertension and diabetes, but hyperlipidemia was more prevalent in the control group I than in cases (72% vs 36%; P = .03). Current smoking was more prevalent in cases (24%) than for patients in control group I (6%) and group II (19%) but not statistically significant (P = .18 and .69, respectively). Thoracic aortic diameters at various points were significantly larger in cases than for patients in control group I. Calcification was more frequent in cases than for patients in control group II. No differences in wall thickness were found. No meaningful correlation was observed between atherosclerotic risk factors and aortic diameter and calcification scores.

Patients with IA have significantly larger and more diffuse dilatation of the thoracic aorta than patients with noninflammatory aneurysms.