Magnetic resonance angiography (MRA) is a non-invasive diagnostic test that is an application of magnetic resonance imaging (MRI). By analyzing the amount of energy released from tissues exposed to a strong magnetic field, MRA provides images of normal and diseased blood vessels as well as visualization and quantification of blood flow through these vessels.

Phase contrast (PC) and time-of-flight (TOF) are the available MRA techniques at the time these instructions are being issued. PC measures the difference between the phases of proton spins in tissue and blood and measures both the venous and arterial blood flow at any point in the cardiac cycle. TOF measures the difference between the amount of magnetization of tissue and blood and provides information on the structure of blood vessels, thus indirectly indicating blood flow. Two-dimensional (2-D) and three-dimensional (3-D) images can be obtained using each method.

Contrast-enhanced MRA (CE-MRA) involves blood flow imaging after the patient receives an intravenous injection of a contrast agent. Gadolinium, a non-ionic element, is the foundation of all contrast agents currently in use. Gadolinium affects the way in which tissues respond to magnetization, resulting in better visualization of structures when compared to un-enhanced studies. Unlike ionic (i.e., iodine-based) contrast agents used in conventional contrast angiography (CA), allergic reactions to gadolinium are extremely rare. Additionally, gadolinium does not cause the kidney failure occasionally seen with ionic contrast agents. Digital subtraction angiography (DSA) is a computer augmented form of CA that obtains digital blood flow images as contrast agent courses through a blood vessel. The computer “subtracts” bone and other tissue from the image, thereby improving visualization of blood vessels. Physicians elect to use a specific MRA or CA technique based upon clinical information from each patient.

Nationally Covered Indications

Head and Neck

Studies have proven that MRA is effective for evaluating flow in internal carotid vessels of the head and neck. However, not all potential applications of MRA have been shown to be reasonable and necessary. All of the following criteria must apply in order for services to be covered for MRA of the head and neck:

1. MRA is used to evaluate the carotid arteries, the circle of Willis, the anterior, middle or posterior cerebral arteries, the vertebral or basilar arteries or the venous sinuses;
   
   
2. MRA is used to verify the need for anticipated surgery for conditions that include, but are not limited to, tumor, aneurysms, vascular malformations, vascular occlusion, or thrombosis. Within this broad category of disorders, medical necessity is the underlying determinant of the need for an MRA. Because MRA and CA perform the same diagnostic function, the medical records should clearly justify and demonstrate the existence of medical necessity; and
   
   
3. MRA and contrast angiography (CA) are not expected to be performed on the same patient for diagnostic purposes prior to the application of anticipated therapy. Only one of these tests will be covered routinely unless the physician can demonstrate the medical need to perform both tests.

Peripheral Arteries of Lower Extremities

Studies have proven that MRA of peripheral arteries is useful in determining the presence and extent of peripheral vascular disease in lower extremities. This procedure is noninvasive and has been shown to find occult vessels in some patients for which those vessels were not apparent when CA was performed. Either MRA or CA to evaluate peripheral arteries of the lower extremities will be covered. However, both MRA and CA may be useful in some cases, such as:

• A patient has had CA and this test was unable to identify a viable run-off vessel for bypass. When exploratory surgery is not a reasonable medical course of action for the patient, MRA may be performed to identify the viable runoff vessel; or
• A patient has had MRA, but the results are inconclusive.

Abdomen and Pelvis

Pre-operative Evaluation of Patients Undergoing Elective Abdominal Aortic Aneurysm (AAA) Repair
The MRA is covered for pre-operative evaluation of patients undergoing elective AAA repair if the scientific evidence reveals MRA is considered comparable to CA in determining the extent of AAA, as well as in evaluating aortoiliac occlusion disease and renal artery pathology that may be necessary in the surgical planning of AAA repair. These studies also reveal that MRA could provide a net benefit to the patient. If preoperative CA is avoided, then patients are not exposed to the risks associated with invasive procedures, contrast media, end-organ damage, or arterial injury.

Imaging the Renal Arteries and the Aortoiliac Arteries in the Absence of AAA or Aortic Dissection
Coverage for MRA includes imaging the renal arteries and the aortoiliac arteries in the absence of AAA or aortic dissection. MRA should be obtained in those circumstances in which using MRA is expected to avoid obtaining CA, when physician history, physical examination, and standard assessment tools provide insufficient information for patient management, and obtaining an MRA has a high probability of positively affecting patient management. However, CA may be ordered after obtaining the results of an MRA in those rare instances where medical necessity is demonstrated.

Chest

Diagnosis of Pulmonary Embolism
Current scientific data has shown that diagnostic pulmonary MRAs are improving due to recent developments, such as faster imaging capabilities and gadolinium-enhancement. However, these advances in MRA are not significant enough to warrant replacement of pulmonary angiography in the diagnosis of pulmonary embolism for patients who have no contraindication to receiving intravenous iodinated contrast material. Patients who are allergic to iodinated contrast material face a high risk of developing complications if they undergo pulmonary angiography or computed tomography angiography. Therefore, MRA of the chest is covered for diagnosing a suspected pulmonary embolism only when it is contraindicated for the patient to receive intravascular iodinated contrast material.

Evaluation of Thoracic Aortic Dissection and Aneurysm
Studies have shown that MRA of the chest has a high level of diagnostic accuracy for pre-operative and post-operative evaluation of aortic dissection of aneurysm. Depending on the clinical presentation, MRA is used as an alternative to other non-invasive imaging technologies, such as transesophageal echocardiography and CT. Generally, coverage will be provided only for MRA or for CA when used as a diagnostic test. However, if both MRA and CA of the chest are used, the physician must demonstrate the medical need for performing these tests.

While the intent of this policy is to provide reimbursement for either MRA or CA, CMS is also allowing flexibility for physicians to make appropriate decisions concerning the use of these tests based on the needs of individual patients. CMS anticipates, however, low utilization of the combined use of MRA and CA.

Nationally Non-covered Indications

Services provided for ineligible conditions will be denied as not medically necessary. A provider cannot bill the member for the denied service unless the provider has given advance written notice, informing the member that the service may be deemed not medically necessary and providing an estimate of the cost. The member must agree in writing to assume financial responsibility, in advance of receiving the service. The signed agreement, in the form of a Pre-Service Denial Notice, should be maintained in the provider's records.

All other uses of MRA for which CMS has not specifically indicated coverage are not covered, e.g., procedure codes 72159 (MRA of the spinal canal and contents) and 73225 (MRA of the upper extremities).

Documentation Requirements

The patient’s clinical records must document the medical necessity for the procedure and that the indications specified as eligible. These records should be available for review upon request.

NOTE:

This policy is designed to address medical guidelines that are appropriate for the majority of individuals with a particular disease, illness, or condition. Each person's unique clinical circumstances may warrant individual consideration, based on review of applicable medical records.

Title XVIII of the Social Security Act, Section 1862(a)(7). This section excludes routine physical examinations.

Title XVIII of the Social Security Act, Section 1862(a)(1)(A) states that no payment shall be made for items or services which are not reasonable and necessary for the diagnosis or treatment of illness or injury.

Title XVIII of the Social Security Act, Section 1833(e) states that no payment shall be made to any provider for any claim that lacks the necessary information to process the claim.

CMS Online Manual Pub. 100-3 on National Coverage Determinations (NCD), Chapter 1, Section 220.2 gives specific coverage guidelines for Magnetic Resonance Angiography (MRA)

CMS Online Manual Pub. 100-4, Chapter 13, Section 40.1

Transmittal 170, CR 2673

Transmittal 1339, CR 5677

National Coverage Analysis (NCA)(#CAG-00142N) Magnetic Resonance Angiography of the Abdomen and Pelvis

Note: This is not an exhaustive list of all national coverage.

Codes 70544-70549:

Code 71555:

Code 73725: