Chronic exertional compartment syndrome: MR imaging at 0.1 T compared with tissue pressure measurement.

Abstract

To compare low-field-strength magnetic resonance (MR) imaging with intracompartmental tissue pressure measurement for the diagnosis of chronic exertional compartment syndrome. Thirteen patients suspected clinically of having chronic exertional compartment syndrome in the anterior tibial compartment were studied. MR imaging 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 obtained in eight anterior tibial compartments of four control subjects without 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 superficial posterior compartment). In the patient group, the relative change from rest to the postexercise state in the normalized MR signal intensity parameter correlated significantly (P < .001) with the respective change in intracompartmental pressure and with the absolute postexercise pressure. In the patients with elevated postexercise intracompartmental pressure, the increase in normalized MR signal intensity from rest to the postexercise state was significantly greater (P < .01) than that in the control subjects or the patients with normal or borderline postexercise intracompartmental pressure. In the latter two groups, the MR results were comparable. MR imaging performed at rest and immediately after muscular exercise is a promising method for diagnosing chronic exertional compartment syndrome and assessing its severity.