On a wrist radiograph, which bone is identified by structure D?

On a wrist radiograph, which bone is identified by structure D?

• A. Pisiform
• B. Lunate
• C. Triquetral
• D. Hamate

Answer: (A)

This question tests your ability to identify carpal bones on a wrist radiograph, focusing on a small, rounded bone that sits on the ulnar side of the proximal carpal row. That structure corresponds to the pisiform, a sesamoid bone embedded in the tendon of flexor carpi ulnaris and lying on the palmar surface just above the triquetrum. Its distinctive, pea-like shape and its position at the base of the palm on the ulnar side make it recognizable as the pisiform on a wrist image. Other carpal bones have different shapes and locations—lunate is centrally located and moon-shaped, triquetrum is larger and behind, and hamate is a hook-shaped bone in the distal row toward the ulna—so the small, round structure on the ulnar side points to the pisiform.

This question tests your ability to identify carpal bones on a wrist radiograph, focusing on a small, rounded bone that sits on the ulnar side of the proximal carpal row. That structure corresponds to the pisiform, a sesamoid bone embedded in the tendon of flexor carpi ulnaris and lying on the palmar surface just above the triquetrum. Its distinctive, pea-like shape and its position at the base of the palm on the ulnar side make it recognizable as the pisiform on a wrist image. Other carpal bones have different shapes and locations—lunate is centrally located and moon-shaped, triquetrum is larger and behind, and hamate is a hook-shaped bone in the distal row toward the ulna—so the small, round structure on the ulnar side points to the pisiform.