Focal Post Traumatic Rhabdomyolysis of Thigh Muscle - USG and CT Imaging

ABSTRACT

Rhabdomyolysis as a term, literally means striated muscle breakdown, where these lysed cells of the muscles produce substances which when released causes severe damage to the body. And to diagnose this medical condition is where the art of imaging comes into picture. And hence, we are presenting a case report on rhabdomyolysis showing distinct ultrasound and CT features.Rhabdomyolysis is the skeletal muscle necrosis with liberation of intracellular substances of the lysed cell into the extracellular fluid and circulation. These substances are electrolytes, purines, enzymes (such as creatine kinase) and myoglobin, which may cause further life-threatening complications.1,2 Diffuse rhabdomyolysis caused due to over-exertion is found in athletes, while focal rhabdomyolysis is rare. Early diagnosis along with its swift management is thus crucial to prevent its complications and Imaging can be a complementary part of the detection and assessment of the extent of rhabdomyolysis. Despite the fact that, the definite diagnosis depends on laboratory tests, imaging studies are usually one of the first modalities used to examine patients. Drugs and other toxic agents, infections, physical exertion, crush injury, and muscle disease are some of the common causes of rhabdomyolysis. And it typically present as muscle fatigue, pain, weakness, and tea-coloured urine. Although in the initial stage of the disease, these clinical symptoms may be subtle and so it is easily missed2. The causes for rhabdomyolysis maybe many, but they often lead to a final common feature, which is muscle tissue breakdown causing myocyte destruction and release of its components into the circulatory system. All these finally lead to muscle ischemia and cell breakdown. Rhabdomyolysis may occur due to traumatic events and the pathophysiology actually takes place once pressure is relieved from the damaged tissue, and the necrotic muscles release their components into circulation.1Muscle ischemia caused by traumatic events interferes with oxygen delivery to the cells, limiting the production of ATP. If oxygen deprivation is maintained for prolonged periods this may result in muscle cell necrosis. Skeletal muscle ischemia may result from either localized or generalized conditions. Localized causes include compression of blood vessels.3