What is the value of Tc-99m hydroxymethylene diphosphonate scintigraphy for the etiological diagnosis of mild rhabdomyolysis?

Aims: We tested whether bone scintigraphy could help in the etiological diagnosis in patients with mild rhabdomyolysis, because different patterns of soft tissue radiotracer uptake have been found on bone scintigraphy in patients presenting with severe rhabdomyolysis, with a localized asymmetric pattern in traumatic lesions and a more diffuse and symmetric pattern in nontraumatic lesions. However, the performance of bone scintigraphy in mild rhabdomyolysis is unknown. The etiological diagnosis of rhabdomyolysis can be difficult, particularly in alcohol abusers who deny a recent alcoholic binge. Material and Methods: Bone scintigraphy was performed in 16 patients presenting with acute renal failure secondary to mild rhabdomyolysis (creatinine kinase levels <= 36,000 IU), with obvious causes in 10 cases and with uncertain etiologies in the remaining 6 patients. Results: In 5 cases with evident traumatic rhabdomyolysis, and in 4 patients with uncertain etiologies, bone scintigraphy showed localized asymmetric soft tissue radiopharmaccutical uptake compatible with traumatic lesions. None of the 5 patients with nontraumatic rhabdomyolysis had significant soft tissue radiopharmaceutical uptake. In 1 patient with traumatic rhabdomyolysis, bone scintigraphy performed only 11 days after the initial insult was negative. One patient with an uncertain etiology also had a negative scintigraphy. Conclusions: Bone scintigraphy, when performed early in the course of the disease, may contribute to the etiological diagnosis of rhabdomyolysis if it shows asymmetric localized soft tissue radiopharmaceutical uptake compatible with traumatic lesions. However, bone scintigraphy is often negative in mild nontraumatic lesions.