Fig. 2
Retrograde angiogram showed the vessel tortuosity or spasms of upper limb artery (the radial artery or the brachial artery) when resistance of a straight, soft-tipped guidewire was encountered. A The radial artery spasms. B An acute angled (Ω-shape) of the radial artery. C A wavy tortuosity (S-shape) of the radial artery. D An annular tortuosity (α-shape) of the radial artery. E Annular tortuosity (α-shape) was present in the proximal segment of the radial artery and the small accessory brachial artery was present. F Annular tortuosity (α-shape) of the brachial artery. G Z-shaped tortuosity of the radial artery. H Z-shaped tortuosity was present in the proximal segment of the radial artery and the small accessory brachial artery was present