Importance of MRI in the diagnosis and treatment of rhabdomyolysis.

BACKGROUND: Rhabdomyolysis is a common disorder resulting from a large variety of causes. We describe the MRI features and their importance for diagnosis and treatment.

PATIENTS AND METHODS: Between 2003 and 2006, four male patients (age range: 25-33 years) with rhabdomyolysis were studied via 1.5 T MRI (GE, Siemens). In all the patients, T1- and T2-weighted sequences with and without fat suppression, short tau inversion recovery (STIR) and gradient-echo sequences were obtained in axial, coronal and sagittal planes. In one patient, contrast material was given.

RESULTS: Two patients presented rhabdomyolysis due to drug abuse, one due to intense exercise and the last one due to long unconsciousness with compression of the paravertebral musculature. Two patients had acute kidney failure. The affected muscles showed an increased signal intensity on T2-weighted and STIR sequences and decreased on T1-weighted sequences. In one patient, intramuscular hemorrhage was observed on T1-weighted and gradient-echo sequences. In the patient with kidney failure, a globular swelling of the kidney with alteration of the corticomedullary differentiation on T2-weighted sequences with fat saturation and hypointensity of the renal medulla on T1-weighted contrast enhanced images was found.

DISCUSSION: Immediate recognition of rhabdomyolysis is important to prevent late complications. MRI is the method of choice to evaluate the distribution and extension of the affected muscles, especially when fasciotomy is considered for treatment. Even though the MRI findings are non-specific, the sensitivity in the detection of muscle involvement is higher than CT or US.