**History/Background and/or General Information**

Magnetic Resonance Angiography (MRA) is an application of magnetic resonance
(MR) imaging that provides visualization of blood flow, as well as images of
normal and diseased blood vessels. Since MRA contrast agents are not
nephrotoxic and are rarely associated with allergic type reactions, MRA
without or with gadolinium-based contrast enhancement is an imaging
alternative for patients who cannot tolerate iodine-based contrast media.

Although MRA appears to be a rapidly developing technology, the clinical
safety and effectiveness of this procedure for all anatomical regions has not
been proven. As a result coverage will be provided on a limited basis. Below
are the indications for coverage allowed for MRA. All other uses of MRA will
not be covered.  
  
**Covered Indications**

Please refer to CMS IOM Publication 100-03, _Medicare National Coverage
Determination (NCD) Manual_ , Chapter 1, Section 220.2 Magnetic Resonance
Imaging for covered MRA Indications for Head and Neck, Peripheral Arteries of
Lower Extremities, Abdomen and Pelvis, and Chest.

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. The medical
record must clearly document the medical necessity of performing both tests.

Examples of indications that support medical necessity of contrast angiography
(CA) performed as an adjunct to MRA:

  * Clarify conditions where test results or clinical information are contradictory (e.g., MRA and duplex Doppler ultrasound are discordant with the clinical differential diagnosis and conventional angiography, with its ability to directly measure pressure gradients across stenosis of questionable hemodynamic significance, can provide more definitive information).
  * Verify the site of clinically important vascular stenosis and help map out the surgical/endovascular approach (e.g., to determine which lesions should have an angioplasty and/or stent vs. which lesions require surgical bypass graft or no treatment at all).
  * Identify situations where MRA is nonconclusive or degraded by metallic artifact.

**Abdomen and Pelvis**

Studies show that diagnostic evaluation of several upper abdominal
malignancies may require an evaluation for vascular invasion by the tumor in
deciding if the patient is a candidate for surgical resection of the tumor.
One example is with pancreatic carcinoma. Pancreatic head carcinomas can grow
in close proximity to the superior mesenteric vein.

Evidence suggests that MRA provides reliable, noninvasive evaluation of the
portal and hepatic veins. MRA can provide focused evaluation of particular
areas of interest as well as a broad overview anatomic display that is helpful
to surgeons and interventionalists planning procedures.

As published in the CMS IOM Publication 100-08, _Medicare Program Integrity
Manual_ , Chapter 13, Section 13.5.4, an item or service may be covered by a
contractor LCD if it is reasonable and necessary under the Social Security Act
Section 1862 (a)(1)(A). Contractors shall determine and describe the
circumstances under which the item or service is considered reasonable and
necessary.