Not all leg pains require an MRI. First of all, it is necessary to have an orthopedic surgeon’s examination to determine the general direction of the disease based on the medical history and the corresponding clinical symptoms and signs, and only if it is considered that an MRI can clarify the disease condition. Clinically, it is more common to see pain and numbness in the whole leg caused by lumbar disc herniation and spinal stenosis, which requires an MRI of the lumbar spine. If the pain is caused by ligament or meniscus injury of the knee joint, MRI of the knee joint is required. If the thigh or calf muscle is severely torn or damaged due to an obvious external injury, an MRI of the corresponding area is required. The MRI is a good way to determine the characteristics and severity of the disease, and therefore the appropriate treatment plan based on the results of the examination.