Figure 5b. Transverse views of the MCP joint of the third finger in flexion, with anatomic correlation. T1-weighted spin-echo (a) conventional MR image (500/12) and (b) MR arthrogram (500/12) and (c) the corresponding anatomic section show the proximal attachments (black arrowheads), distal attachments (white arrowheads), and taut body (arrow) of the main collateral ligament.