Background On May 12, 2008, a major earthquake hit Wenchuan County in Sichuan Province of China. The number of cases of crush injury following this event was high. Ultrasonic appearance of rhabdomyolysis （RM） caused by crush injury in the Wenchuan earthquake was observed to evaluate the diagnostic value of ultrasound for detection of rhabdomyolysis. Methods We analyzed clinical and ultrasonic manifestations of 50 cases of RM and 18 cases of RM with osteofascial compartment syndrome （OCS）. All cases were caused by crush injury in the Wenchuan earthquake. For these RM patients, we also evaluated the correlations between creatine kinase （CK） and the scope of the muscle lesions as observed by ultrasound. Results There were differences in clinical symptoms, physical signs and ultrasonic appearance between the two groups of patients. The ultrasonic characteristics of the RM were as follows： the striated muscle in the lesions thickened with good overall continuity, and the muscle texture was vague; the strength of the echo was uneven and the echo was cloudy or ground glass-like. Liquid dark zones appeared between muscles and were spindle-like or irregular in shape. There were no blood flow signals in the liquid dark areas. The volume of the striated muscle increased in patients with OCS; the fascia wrapping the muscle showed arched protrusions and significant displacement. The flow velocity of the distal arteries decreased and the spectrum was abnormal. The muscle lesion scope of RM group and RM and OCS group was （7.8±2.0） cm and （13.6±3.1） cm, respectively. The correlation coefficient （r） between the muscle lesion scope and the CK was 0.681 for the RM group （P 〈0.05） and 0.516 for the RM and OCS group （P 〈0.05）. Conclusions The ultrasonogram of RM has characteristic manifestations and can provide important information for clinical diagnosis and treatment of rhabdomyolysis.
