After leg pain has arisen, a CT exam can detect lesions if they are bony, but if they are due to muscles, nerves, blood vessels, and other soft tissues, they are not visible on CT. When leg pain arises, a lot of problems can indeed be detected by CT, including bone tumors, fractures, cystic changes in the bone, and other changes, including osteoarthritis, which can be detected by CT. Diseases that cause leg pain are not simply bone lesions, but also include nerve and muscle lesions as well as blood vessel lesions, which cannot be detected by CT examination alone, and require other further examination to confirm the diagnosis.