CHRONIC EXERTIONAL COMPARTMENT SYNDROME - MR-IMAGING AT 0.1 T COMPARED WITH TISSUE PRESSURE MEASUREMENT

PURPOSE: To compare low-field-strength magnetic resonance (MR) imaging with intracompartmental tissue pressure measurement for the diagnosis of chronic exertional compartment syndrome. MATERIALS AND METHODS: Th irteen patients suspected clinically of having chronic exertional comp artment syndrome in the anterior tibial compartment were studied. MR i maging at 0.1-T and intracompartmental tissue pressure measurements of the anterior tibial compartment were performed before and immediately after standard treadmill exercise. The MR measurements were also obta ined in eight anterior tibial compartments of four control subjects wi thout the syndrome. Intracompartmental signal intensity was normalized with the signal intensity from lower leg tissues not affected by the compartment syndrome (subcutaneous fat, tibial bone marrow, or superfi cial posterior compartment). RESULTS: In the patient group, the relati ve change from rest to the postexercise state in the normalized MR sig nal intensity parameter correlated significantly (P < .001) with the r espective change in intracompartmental pressure and with the absolute postexercise pressure. In the patients with elevated postexercise intr acompartmental pressure, the increase in normalized MR signal intensit y from rest to the postexercise state was significantly greater (P < . 01) than that in the control subjects or the patients with normal or b orderline postexercise intracompartmental pressure. In the latter two groups, the MR results were comparable. CONCLUSION: MR imaging perform ed at rest and immediately after muscular exercise is a promising meth od for diagnosing chronic-exertional compartment syndrome and assessin g its severity.