Fig. 1

Selected axial CTA images (64 slice CT scanner) in craniocaudal order. Thickened vessel wall and infiltration (thick arrow C, D) surrounding the aortic arch and occluded supra-aortic vessels (thin arrows B) and occluded aorto-carotid bypass (curved arrow B, C). The collateral artery (dotted arrow A–D) arising from the right coronary artery is connected to the left vertebral artery that is one of the few vessels delivering cerebral blood supply. An additional collateral artery arising from the intercostal arteries feeds the right subclavian artery and thereby the right vertebral artery (long thin arrow A). Both subclavian arteries depend on collateral blood supply derived from intercostal collaterals