Arthrography for Sports Injuries

Arthrography is an X-ray examination using a contrast agent to examine a joint, such as the knee or shoulder. In arthrography, serial X-rays are taken of the joint being examined in various positions after a contrast agent is injected into the joint. This examination is most often used to examine the knee and shoulder joints, but can also be used for other joints, such as the wrist, ankle, hip, or elbow. Similarly, direct MR arthrography also involves the injection of contrast material into the joint. The contrast material used for MR evaluation is different from that used for x-rays; it contains the substance gadolinium, which affects the local magnetic field in the MRI channel and shows up on the MR image. As in conventional direct arthrography, the contrast material outlines anatomical structures within the joint, such as cartilage, labrum, ligaments, and bones, and allows them to be evaluated after the MR image is produced. Direct CT arthrography uses the same type of contrast material as conventional direct arthrography using x-rays and can be supplemented with air to produce double-contrast CT arthrograms. CT creates cross-sectional images that are processed by a computer using x-rays.