Patterns of aortic involvement in Takayasu arteritis and its clinical implications: Evaluation with spiral computed tomography angiography

Objective: Although the luminal changes of Takayasu arteritis are well depicted with conventional angiography, its mural changes can be best evaluated with spiral computed tomography (CT) angiography. Here, the authors investigated the patterns of aortic involvement in Takayasu arteritis by using CT angiography. Methods. CT angiography was performed from the carotid bifurcation to the iliac bifurcation in a consecutive 85 patients (M:F = 10:75, mean age: 37 years) with Takayasu arteritis. Two radiologists interpreted axial images and three-dimensional reconstructed images by consensus with respect to disease extent, lesion continuity, and disease activity based on mural and luminal changes on CT angiography. Results. Eighty-one (95%) patients had aortic involvement with or without aortic branch involvement, and the other four (5%) patients had only aortic branch involvement. In terms of aortic branches, the left common carotid artery (77%) and the left subclavian artery (76%) were most commonly involved. Extent of disease involvement assessed by mural change was wider than that assessed by luminal change in 52 (61%) patients. Although arterial involvement was contiguous in 69 (81%) patients, skipped lesions were identified in 16 (19%) patients. An analysis of mural findings revealed the coexistence of active and inactive lesions in nine (11%) patients. Conclusions: Aortic involvement in Takayasu arteritis can occur from the aortic root to below the iliac bifurcation, and isolated branch vessel involvement is also possible. In most patients, aortic involvement occurs in a contiguous, synchronous fashion. However, skipped involvement and the coexistence of active and inactive lesions also occur.