Magnetic resonance imaging (MRI), formerly called nuclear magnetic resonance (NMR), is a noninvasive method of graphically representing the distribution of water and other hydrogen-rich molecules in the human body. In contrast to conventional radiographs or computed tomography (CT) scans, in which the image is produced by x-ray beam attenuation by an object, MRI is capable of producing images by several techniques. In fact, various combinations of MRI production methods may be employed to emphasize particular characteristics of the tissue or body part being examined. 

The basic elements by which MRI produces an image are the density of hydrogen nuclei in the object being examined, their motion, the relaxation times, and the period of time required for the nuclei to return to their original states in the main, static magnetic field after being subjected to a brief additional magnetic field. These relaxation times reflect the physical and chemical properties of tissue and the molecular environment of its hydrogen nuclei. Only hydrogen atoms are present in human tissues in sufficient concentration for current use in clinical MRI.

MRI is a useful diagnostic imaging modality that is capable of demonstrating a wide variety of soft-tissue lesions with contrast resolution equal or superior to CT scanning in various parts of the body. Among the advantages of MRI are the absence of ionizing radiation and the ability to achieve high levels of tissue contrast resolution without injected iodinated radiological contrast agents. Recent advances in technology have resulted in development and Food and Drug Administration (FDA) approval of new paramagnetic contrast agents for MRI that allow even better visualization in some instances. 

Multi-slice imaging and the ability to image in multiple planes, especially sagittal and coronal, have provided flexibility not easily available with other modalities. Because cortical (outer layer) bone and metallic prostheses do not cause distortion of MRI, it has been possible to visualize certain lesions and body regions with greater certainty than has been possible with CT. The use of MRI on certain soft tissue structures for the purpose of detecting disruptive, neoplastic, degenerative, or inflammatory lesions has now become established in medical practice.

Contrast Material
When an MRI is considered reasonable and necessary, payment can also be made for the contrast materials used to perform the study. 

Nationally Covered Indications

Although several uses of MRI are still considered investigational and some uses are clearly contraindicated, MRI is considered medically efficacious for a number of uses. Use the following descriptions as general guidelines or examples of what may be considered covered rather than as a restrictive list of specific covered indications.

• Coverage is limited to MRI units that have FDA premarket approval, and such units must be operated within the parameters specified by the approval.
• The services must be reasonable and necessary for the diagnosis or treatment of the specific patient involved. 

The MRI is useful in examining the head, central nervous system, and spine. Multiple sclerosis can be diagnosed with MRI and the contents of the posterior fossa are visible. The inherent tissue contrast resolution of MRI makes it an appropriate standard diagnostic modality for general neuroradiology. The MRI can assist in the differential diagnosis of mediastinal and retroperitoneal masses, including abnormalities of the large vessels such as aneurysms and dissection. 

When a clinical need exists to visualize the parenchyma of solid organs to detect anatomic disruption or neoplasia, this can be accomplished in the liver, urogenital system, adrenals, and pelvic organs without the use of radiological contrast materials. 

MRI may also be used to detect and stage pelvic and retroperitoneal neoplasms and to evaluate disorders of cancellous bone and soft tissues. It may also be used in the detection of pericardial thickening. Primary and secondary bone neoplasm and aseptic necrosis can be detected at an early stage and monitored with MRI. Patients with metallic prostheses, especially of the hip, can be imaged in order to detect the early stages of infection of the bone to which the prosthesis is attached.

Disc Disease Diagnosis
The MRI may also be covered to diagnose disc disease without regard to whether radiological imaging has been tried first to diagnose the problem. 

Gating Devices and Surface Coils
Gating devices that eliminate distorted images caused by cardiac and respiratory movement cycles are now considered state-of-the-art techniques and may be covered. Surface and other specialty coils may also be covered, as they are used routinely for high resolution imaging where small limited regions of the body are studied. They produce high signal-to-noise ratios resulting in images of enhanced anatomic detail. 

Contraindications and Nationally Noncovered Indications

Contraindications

• The MRI is not covered when the following patient-specific contraindications are present.
• It is not covered for patients with cardiac pacemakers or with metallic clips on vascular aneurysms. 
• MRI during a viable pregnancy is also contraindicated at this time.  
• The danger inherent in bringing ferromagnetic materials within range of MRI units generally constrains the use of MRI on acutely ill patients requiring life support systems and monitoring devices that employ ferromagnetic materials. 
• In addition, the long imaging time and the enclosed position of the patient may result in claustrophobia, making patients who have a history of claustrophobia unsuitable candidates for MRI procedures. 

Nationally Noncovered Indications

The CMS has determined that blood flow measurement, imaging of cortical bone and calcifications, and procedures involving spatial resolution of bone and calcifications (codes 75558, 75560, 75562, 75564), are not considered reasonable and necessary indications within the meaning of section 1862(a)(1)(A) of the Social Security Act, and are therefore noncovered. 

Other Uses

All other uses of MRI for which CMS has not specifically indicated coverage or noncoverage continue to be eligible for coverage through individual consideration. 

A diagnostic technique has been developed under which an MRI of the brain or spine is first performed without contrast material, then another MRI is performed with a standard dose of contrast material. Then, based on the need to achieve a better image, a third MRI may be performed with an additional double dosage of contrast material. No additional  payment is made for the third MRI procedure. For example, when an MRI of the brain is performed without contrast material, followed by with contrast material(s) and further sequences) code 70553 should be reported. However, no additional payment can be made for the third MRI procedure because procedure code 70553 includes all further sequences.

Documentation Requirements

Documentation in the patient’s clinical records must document the medical necessity for performing the MRI and be available 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 220.0

CMS Online Manual Pub. 100-4, Chapter 13, Section 40