T1 axial before and 5 months after surgery of a radial tunnel syndrome (= supinator syndrome). The postoperative examination was performed because of increasing weakness in the forearm. It shows a marked atrophy (purple arrows) and denervation edema (orange arrows) of the superficial part of the supinator muscle. Red arrows: Normal supinator muscle, superficial part. Green arrow: Normal supinator muscle, deep part. Blue arrow: Arcade of Frohse with deep branch of radial nerve.