Radiology Coding Alert

Many radiology coders may wonder how to report magnetic resonance imaging (MRI) of the shoulder, as opposed to magnetic resonance arthrography. In addition, others wonder how to code MR arthrography as opposed to conventional arthrography.

Differences Between MRI and MR Arthrography

MRIs and MR arthrographies have their similarities but are considerably different studies, explains Ellen Ratnofsky, RN, BSN, CS, of Healthcare Administrative Partners Inc., which provides medical billing and practice management services in seven states. An MRI is a more generalized procedure providing images of soft tissue, while MR arthrography supplies greater detail of the bony areas directly at the shoulder joint. MR arthrography actually includes an MRI.

She also notes that a radiology technologist may perform an MRI, but MR arthrography requires the expertise of a radiologist.

A standard MRI with contrast is reported using CPT 73221 (magnetic resonance [e.g., proton] imaging, any joint of upper extremity), she says. During an MRI with contrast, the medium is injected intravenously and images are taken of how it progresses through the limb.

MR arthrography of the shoulder, however, includes an intra-articular injection of contrast, usually gadolinium. In other words, the agent is delivered directly into the cavity of the joint. The injection often is aided by fluoroscopic guidance to ensure that the needle is positioned correctly. This is then followed by an MRI study.

The MR arthrogram would be assigned codes CPT 23350 (injection procedure for shoulder arthrography) for the shoulder injection, followed by the MRI code 73221. Although fluoroscopic guidance is used during the injection procedure, it would not be coded separately. According to the Correct Coding Initiative (CCI), the fluoroscopy would be bundled into 23350.

Diagnosing Specific Conditions

MRIs of the shoulder most often are done when a patient is experiencing joint pain, 719.41 (pain in joint, shoulder region), and the physician is trying to diagnose a specific problem in the soft tissue, like a tear in the rotator cuff, 840.4 (sprains and strains of shoulder and upper arm; rotator cuff [capsule]), explains Brian Effron, CHMBE, president of Healthcare Administrative Partners, which has offices in Media, Pa.; Newton, Mass.; and Portsmouth, N.H. Magnetic resonance arthrography, on the other hand, is performed when more serious pathology is suspected.

Ratnofsky adds that these may include osteomyelitis, 730.01 (acute osteomyelitis of the shoulder region), circulatory disorders like an embolism or thrombosis, 444.21 (arterial embolism and thrombosis; of arteries of the extremities; upper extremity), or cancer (e.g., 195.4, malignant neoplasm of other and ill-defined sites; upper limb; or 170.4, malignant neoplasm of bone and articular cartilage; scapula and long bones of upper limb).

MR Arthrography Considered Investigational

Some clinicians cite advantages for an MR arthrogram over the more traditional MRI. There is no radiation involved with magnetic resonance imaging, whereas a CAT scan includes x-ray exposure, Ratnosfky points out. In addition, MR arthrography can be done with a contrast agent that has a very low incidence of adverse reaction, and so may be preferred with patients who have allergies to contrast agents.

But Ratnofsky adds a cautionary note to radiology practices using MR arthrography. In many areas it is still considered investigational. If so, claims for imaging studies for the shoulder and other areas may be denied.

Effron notes that coders should check with local carriers and ask that requirements and guidelines for these studies be provided in writing to ensure they dont get denied.

Coding Conventional and MR Arthrography

Ratnofsky points out that a conventional arthrogram, or joint study, is rarely done in conjunction with an MR arthrography. During conventional arthrography of the shoulder, local anesthesia is instilled at the site of the joint, and a needle is inserted into the joint cavity. Fluid that may have collected in the space is aspirated and sent for analysis. Contrast media and air then are inserted into the cavity under fluoroscopic guidance. Multiple x-rays and, on occasion, MR images then are taken.

The procedure would be coded 23350 for the injection and 73221 for the imaging, just as with MR arthrography. In addition, 73040 (radiologic examination, shoulder, arthrography, radiological supervision and interpretation) would also be reported, Ratnofsky says.