Rhabdomyolysis of Unknown Etiology - Initial Suspicion and Detection on 99mTc-MDP Skeletal Scintigraphy.

The classical bone scan findings of Rhabdomyolysis is presented in this illustration. A 60 year old female patient with complaints of low backache and bilateral lower limbs weakness over 1 year was referred for whole body skeletal status evaluation. Whole body skeletal scintigraphy undertaken 3 hrs after I.V injection of 15 mci of 99mTc-MDP revealed bilaterally symmetrical diffuse skeletal muscle tracer activity in deltoid, lattisimus dorsi, diaphragm, paraspinal muscles, gluteus muscles and muscles of thigh. On biochemical investigations for evaluation of skeletal muscle uptake revealed elevated serum creatinine, LDH, serum potassium. The ultrasonography of kidney revealed grade I renal parenchymal changes. ECG showed normal findings. Rhabdomyolysis manifests with muscle pains, restricting muscle activity and may present with low backache. Etiology of Rhabdomyolysis is nonspecific and can occur due to many causes (usage of drugs such as antipsychotics, statins, alcohol, toxemia, infections, malignant hyperthermia, heat stroke, crush injury etc).1-3 In our case no inciting cause of Rhabdomyolysis could be elicited. CT scan can reveal calcification of muscles with nonspecific hypo-attenuating areas in the involved muscles. Bone scan has the advantage of evaluating the whole body in a single examination.