Fig. 2From: A case with Behçet’s disease involving erosive Metacarpophalangeal joint arthritis: the value of ultrasonography in the diagnosis of an ErosionThe longitudinal images of the second MCP joint in dorsal aspect (a): A normal articular surface (white arrow) of the second MCP joint. (b): The appearance of the erosion (red arrow) as the step-down contour defectBack to article page