The National Institute of Arthritis and Musculoskeletal and Skin Diseases explains the differences.
- A CT scan (computerized axial tomography) takes pictures of the knee for fractions of a second from different angles. Unlike regular X-rays, a CT scan can show soft tissues like cartilage and ligaments.
- A bone scan uses radioactive material injected into the patient's bloodstream that is tracked as it flows to the bone, offering a look at possible abnormalities in cell activity.
- An MRI uses a powerful magnet to create pictures of sections of the knee. This test is particularly useful in detecting soft-tissue injuries.
- Arthroscopy uses a lighted optical tube inserted into the knee. A doctor moves the scope inside the knee looking for problems. The scope may be used to help fix any damage found.