Ultrasound of muscles.

Muscles are among the soft tissues one of the best adapted to ultrasound examination. In fact, it was the first imaging available for the evaluation of muscle disease. The availability, low cost, and ease of examination makes ultrasound superior to MRI for follow-up of lesions and searching for healing problems such as as fibrosis, cystic haematomas, or myositis ossificans. When dealing with fresh traumatic muscle lesions, the main goal of ultrasound is to assess the presence of a muscle tear or not. Haematoma is the key sign of a muscle tear. The ideal time for the examination is between 2 and 48 h after the muscle trauma. Before 2 h, the haematoma is still in formation. After 48 h, the haematoma can be spread outside of the muscle. After healing, ultrasound can depict some complications such as a cystic lesion or myositis ossificans. Muscle atrophy, inflammation, avulsion and tumours are also good indications for ultrasound.