What procedure involves injecting an opaque dye into a joint space for imaging?

Arthrography is a procedure specifically designed for imaging a joint space by injecting an opaque dye, also known as a contrast agent, into the joint. This contrast dye enhances the visibility of the structures within the joint, such as cartilage, tendons, and ligaments, during imaging techniques like X-rays or MRI. This allows clinicians to evaluate any injuries or conditions affecting the joint, making it a valuable diagnostic tool in orthopedics and sports medicine.

In contrast, myelography involves injecting dye into the spinal canal, primarily to visualize the spinal cord and nerve roots, not a joint space. Computed tomography (CT) is a diagnostic imaging technique that creates detailed images of internal structures but does not involve injecting a dye into a joint space specifically. A bone scan is a nuclear imaging technique used to detect bone diseases or conditions but does not involve direct injection into a joint. Therefore, the clarity and specificity of arthrography in the context of joint imaging highlight why it is the correct choice for this question.