MRI of wrist showing Guyon canal

The pisiform (PI) is the main bony landmark for the Guyon canal. The ulnar nerve (arrowhead) lies just radial to the pisiform; the ulnar artery (dashed arrow) more laterally. The flexor retinaculum covers the carpal tunnel. The ulnar nerve and artery show high signal intensity on MRI, while the median nerve (arrow) lies superficial to the flexor tendons.