Fig. 1. Type 1 variant on diagrams and axial MR images.

A. Schematic of Type 1 variant. B. Type 1A variant (classical configuration of Lister's tubercle). C. Type 1B variant wherein radial (r) peak is dominant with box-like configuration and ulnar peak (u) is small. ECRB = extensor carpi radialis brevis, ECRL = extensor carpi radialis longus, EPL = extensor pollicis longus