Effect of foot and ankle MR imaging on clinical decision making.

PURPOSE: To evaluate the effect of magnetic resonance (MR) imaging of the ankle and hindfoot on clinical decision making.

MATERIALS AND METHODS: Eighty-one consecutive patients were prospectively examined with MR imaging of the foot and ankle. The referring clinician (one of two orthopedic surgeons or one of two podiatrists) assigned a clinical diagnosis (with a corresponding confidence score of 1-5) and a tentative treatment plan before and after the MR imaging examination and reading. A two-tailed, paired Student t test was used to determine the effects of MR imaging on the diagnosis and treatment.

RESULTS: Of the 81 patients examined, 38 (47%) had a post-MR imaging diagnosis that differed from the pre-MR imaging diagnosis (P < .001). Treatment plans were subsequently changed in 28 patients (34%) (P < .001). MR imaging had a statistically significant effect regardless of the assigned, pre-MR imaging clinical confidence rating. MR imaging was also noted to play a key role in surgical planning regardless of the effect on diagnosis.

CONCLUSION: MR imaging of the foot and ankle has an effect on clinical decision making. Regardless of the clinician's confidence in diagnosis, MR imaging consistently plays a central role in further defining the diagnosis and treatment.