Tarsal coalition: depiction and characterization with CT and MR imaging.

PURPOSE

To compare computed tomography (CT) and magnetic resonance (MR) imaging in the detection, localization, and characterization of tarsal coalitions.

MATERIALS AND METHODS

Preoperative CT and MR images were obtained for 10 feet in nine patients (eight male and one female patients), aged 11-18 years who were unresponsive to conservative therapy. Results from two blinded readers were compared with results from surgery.

RESULTS

Five calcaneonavicular and four medial subtalar coalitions were found at surgery. One patient had synovitis. CT depicted six coalitions and four were characterized correctly, but the fibrous coalitions were not characterized correctly. MR depicted all coalitions and seven were characterized correctly, including the fibrous coalitions. At MR imaging, proliferative synovitis was incorrectly characterized as a fibrous coalition.

CONCLUSION

These results suggest that MR imaging depicts all coalitions but may not be able to help differentiate synovitis from fibrous coalitions and that CT has limitations in the depiction of fibrous coalitions.