Arthrogram

An arthrogram is a series of X-rays of a joint after injection of a contrast medium. The injection is normally done under a local anesthetic.The radiologist performs the study utilizing flouroscopy to guide the placement of the needle into the joint and then injects an appropriate quantity of contrast. The physician or technologist then obtains a series of X-rays. The joint can be imaged from many angles and the consultant/radiologist can assess the images produced in real time.

Purpose/Description/Indications: Radiography to visualize the soft tissue structures of a joint or joints (menisci, ligaments, articular cartilage, bursae). The contrast study can be done on any encapsuled joint; however, the shoulder is the most frequent site of investigation. Arthrogram examinations are usually done with a local anesthetic. The injection is made under careful aseptic conditions in combination with fluoroscopic-radiographic examining room, which should be carefully prepared in advanced.

Contraindications/Risks: Contraindications are patients who are allergic to or sensitive to medications, contrast dyes, local anesthesia, iodine, or latex. Potential risks are infections at the puncture site where the radiopaque substance and/or air are injected.

Contrast: For pneumoarthrography, a gaseous medium is used, for opaque arthrography a water-soluble iodinated medium is used and a combination of both is used in double-contrast arthrography.

Patient Prep/Patient Position: The patient is asked to remove any clothing, jewelry, or other objects that may interfere with the area of interest. The area around the joint is scrubbed with an anti-bacterial soap and covered with sterile drapes, usually leaving a small space for the injections.

Equipment/Types of Images: The exam is done under the fluoroscope to guide the needle into the correct place in the joint.

Findings: Shoulder arthrography can be used to study tears of the rotator cuff. The procedure can also define subtle abnormalities of the bicipital tendon and sheath, and can demonstrate the nature of periarticular soft tissue masses. Alternative Exams: MRI allows a noninvasive imaging technique to evaluate joints.

MR Arthrogram
Increasingly utilized in the last ten years, MR Arthrography combines a standard arthrogram with Magnetic Resonance imaging. While preparing the Iodine contrast for injection into the joint, the physician adds a small quantity (usually less than 1 ml) of gadolinium contrast. Once the joint has been injected and the traditional radiographic images have been obtained, the patient then undergoes an MR of the joint. The gadolinium in the contrast fluid yields a bright hyperintense signal and allows evaluation of quite small defects of the joint capsule, articular surface of the bones and of the labral cartilage. MR arthrography is most often used in evaluation of the hip and acetabular labrum, of the shoulder rotator cuff and glenoid labrum and less often in the wrist.