Radiology Coding Alert

Magnetic resonance angiography (MRA) is a noninvasive diagnostic procedure slowly gaining acceptance by payers throughout the country. Nonetheless, reimbursement policies are narrowly defined and coding professionals must keep abreast of limitations and restrictions placed upon its use by local Medicare carriers.

It is especially important to note that approved uses of MRA differ, depending on the body site being imaged. For instance, Medicare approved the use of MRA for the chest and abdomen here in Wisconsin on July 1, 1999, says Bernadette Raasch, RTR, who works with the radiology department at the Medical College of Wisconsin. (MRA of the chest: CPT 71555 , magnetic resonance angiography, chest [excluding myocardium], with or without contrast material[s]; MRA of the abdomen: CPT 74185 , magnetic resonance angiography, abdomen, with or without contrast material[s]).

Prior to that, there were reimbursement policies in place only for MRAs of the head and neck and of the lower extremities. (MRA of the head and neck: 70541, magnetic resonance angiography, head and/or neck, with or without contrast material[s], MRA of the lower extremities: 73725, magnetic resonance angiography, lower extremity, with or without contrast material[s]).

Even with these recent policy changes, she adds, coders cant assume that MRA imaging will be approved in all situations. Here in Wisconsin, we have found that only a narrow window of diagnostic codes are acceptable for reimbursement, Raasch says. I strongly recommend that all coders read their states Medicare policy closely to find what they will allow.

Radiologists also must be aware that most carriers will not reimburse for both MRAs and the more traditional contrast angiography (CA) on the same patient, she notes. For instance, the Wisconsin Medicare policy states that only one of these tests will routinely be covered unless the physician can demonstrate the medical need to perform both.

MRA of the Chest CPT 71555

Susan Callaway-Stradley, CPC, CCS-P, an independent coding consultant and educator in North Augusta, S.C., reports that an informal survey of local Medicare review policies (LMRPs) throughout the country indicates that reimbursement for MRAs of the chest is the most restrictive. In fact, she says, it has been approved in only two circumstances: for the diagnosis of pulmonary embolism (995.2, unspecified adverse effect of drug, medicinal and biological substance; and 414.1, aneurysm of heart or 415.11, iatrogenic pulmonary embolism and infarction) and for the evaluation of thoracic aortic dissection and aneurysm (441.2, thoracic aneurysm without mention of rupture; 441.7, thoracoabdominal aneurysm, without mention of rupture; 444.1, arterial embolism and thrombosis of thoracic aorta; and V67.0, follow-up examination; following surgery).

Furthermore, the restrictions for utilizing MRAs in cases of pulmonary embolism are especially limiting. The LMRPs studied indicate that MRA may be used only in patients who are allergic to iodinated contrast materials and who risk developing significant complications, Callaway-Stradley says. Therefore, most patients must continue to be diagnosed using traditional pulmonary angiography. (Although there are a number of applicable codes in situations like this, one example might be 75741, angiography, pulmonary, unilateral, selective, radiological supervision and interpretation.)

However, chest MRAs for pre- and postoperative evaluation of aortic dissection of aneurysm are less restricted, because studies have clearly shown they have a high level of diagnostic accuracy.

MRAs of the Abdomen CPT 74185

Most Medicare carriers recognize MRA of the abdomen as a reliable diagnostic tool for the pre-operative evaluation of patients scheduled to undergo elective abdominal aortic aneurysm (AAA) repair
(ICD-9 aortic aneurysm and dissection codes 441.0441.9), says Callaway-Stradley. An MRA, like a CA, may be used to determine the extent of the AAA, as well as for evaluating the aortoiliac occlusive disease and renal artery pathology that may be necessary in the surgical planning for AAA repair.

Most of the policies note, however, that radiologists should choose to perform either a CA or an MRA, after other tests have been used to diagnose AAA and evaluate the aneurysm over time. These would include computerized tomography (i.e. 74150, computerized axial tomography, abdomen; without contrast material) or ultrasound (i.e. 76700, echography, abdominal, B-scan and/or real time with image documentation; complete).

As with the chest, most payers allow the use of MRAs when the use of contrast material is contraindicated (i.e., allergic reaction).

MRA of the Peripheral Arteries of the Lower Extremities CPT 73725

MRA has long been considered an effective method to determine the presence and extent of peripheral vascular disease in the lower extremitiesand often may be more effective than CA in finding occult vessels with some patients. Some practices may rarely use MRA with CA, Callaway-Stradley says, but both may be performed in some situations. It may be appropriate, for instance, for a radiologist also to perform an MRA if the CA alone was unable to identify run-off vessels for bypass. Likewise, a physician may order a CA if results from an MRA are inconclusive.

Common indications for an MRA of the lower extremities may include evaluation of the femoral and popliteal arteries, for example (444.22, arterial embolism and thrombosis; lower extremity), for suspected embolism or thrombosis, and as a noninvasive follow-up exam in patients with prior revascularization procedure (i.e., V45.81, aortocoronary bypass status).

MRA of the Head and Neck CPT 70541

MRA has been used for many years to evaluate the blood flow in internal carotid vessels that are located in the head and neck, including the circle of Willis; the anterior, middle or posterior cerebral arteries; the vertebral or basilar arteries; and the venous sinuses. It is most often performed on patients with conditions of the head and neck for which surgery is anticipated, including tumors, aneurysms, vascular malformations vascular occlusions or thrombosis, notes Callaway-Stradley.

Common conditions where MRA may be ordered include suspected non-ruptured intracranial aneurysms (i.e., 437.3, cerebral aneurysm, nonruptured), arteriovenous malformations or AVM (i.e., 447.0, arteriovenous fistula, acquired) and carotid stenosis (433.10, occlusion and stenosis of carotid artery; without mention of cerebral infarction).

What is Magnetic Resonance Angiography? According to information distributed by the Health Care Financing Administration (HCFA), MRA is an adoption of magnetic resonance imaging (MRI) technology, and is used to diagnose and evaluate obstructive vascular lesions. It provides a three-dimensional visualization of blood flow, as well as images of normal and diseased blood vessels in essence, duplicating the route of the flow of blood. MRA creates these images without the use of contrast agents, which may cause allergic reactions or other problems in some patients. When a body part is placed in the magnetic field during an MRA, it yields signals. Blood flowing through vessels produces a signal intensity that is different than that of surrounding stationary vascular tissue. Using this data, a computer then reconstructs a series of cross-sectional images to create a vascular image similar to angiographic versions. This allows the radiologist to evaluate possible obstructions so the proper course of treatment may be undertaken. MRA techniques have developed rapidly, but accuracy varies widely and, in some applications, it is still considered investigational. It is best suited to survey a specific site, rather than large body regions.