Objective To explore the imaging characteristics and clinical value of CT angiography (CTA) of the aorta in children with Takayasu arteritis (TA).

Method We conducted a retrospective analysis of clinical data, imaging data, and laboratory examination results of 11 children with TA admitted to People’s Hospital of Xinjiang Uygur Autonomous Region from January 2016 to September 2022. The patients comprised 1 male and 10 females (8 adolescent girls). The age was (14.3±3.7) years. The course of the disease was (24.3±37.9) months. All children underwent chest and abdominal CT plain scan, aortic CTA, and post-processing examination, including multi-plane reconstruction, maximum density projection, volume reconstruction, and surface reconstruction. The imaging features of pediatric TA were analyzed, and the Numano classification was determined. Moreover, we observed the extent and degree of involvement of the aorta, branches, and pulmonary arteries, as well as the wall (thickening, calcification, high-density ring sign, low-density ring sign, and uneven enhancement), lumen (stenosis, dilation, and positive remodeling), and perivascular adipose tissue.

Result Among the 11 children with TA, 9 were in the active phase (81.8%, 9/11), 10 were complicated with hypertension (90.9%, 10/11), 5 were accompanied with systemic symptoms (45.5%, 5/11), 4 were accompanied with cardiac symptoms (36.4%, 4/11), and 3 were accompanied with central nervous system symptoms (27.3%, 3/11), of which 1 case was complicated with hypertensive encephalopathy (9.1%, 1/11). There were 5 cases of elevated C-reactive protein and 5 cases of decreased hemoglobin (45.5%, 5/11), and there were 4 cases of elevated red blood cell sedimentation rate, white blood cell count, and platelet count (36.4%, 4/11). The most common types of Numano classification were IV and V, with a total of 10 cases (90.9%, 10/11); 11 cases (100%, 11/11) involved the descending aorta, 10 cases (90.9%, 10/11) involved the renal artery, 5 cases (45.5%, 5/11) involved the aortic arch and its branches, and 2 cases (18.2%, 2/11) involved the pulmonary artery. All 11 cases (100%, 11/11) of TA children showed increased wall density on CT plain scan, presenting as a high-density ring sign, and 3 cases (27.3%, 3/11) had wall calcification. Nine cases (81.8%, 9/11) of active children had perivascular adipose tissue opacity. In all 11 cases of CTA, the aorta and its branches were diffusely and multi-segmentally involved, with thickening of the wall (3.1±0.9) mm and uneven enhancement. Eight cases (72.7%, 8/11) showed a low-density ring sign in the inner wall. Renal artery stenosis in the aortic branches had the highest incidence (90.9%, 10/11), with 2 cases (18.3%, 2/11) of pulmonary artery involvement with stenosis and/or occlusion of the lumen and 4 cases of aortic dilation (36.4%, 4/11).

Conclusions Aortic CTA can clearly display the aorta and its branches and pulmonary arteries. It can also comprehensively display the situation of affected blood vessels. Analyzing the CTA imaging features of children with TA is of great significance for the screening, diagnosis, and evaluation of the disease.