fig1

Figure 1. The procedure for measuring the morphological variables of the ascending aorta and aortic arch in a patient with aTBAD. (A and B) Aortic angulation was the angle created by tangent lines drawn at the proximal and distal points of the centerline within the ascending aorta and aortic arch segments. Aortic tortuosity was measured as the ratio of the centerline length of the ascending aorta and aortic arch segments (L1, L2) to the direct linear distance between the proximal and distal points (D1, D2); (C) The diameter, length and volume of each aortic segment were measured between the STJ, BCT and the distal left subclavian artery in the stretched vessel view. STJ: Sinotubular junction; BCT: brachiocephalic trunk; aTBAD: acute type B aortic dissection.