Magnetic resonance spectroscopy (MRS) (code 76390) is eligible for the following indications:

• To assess the evidence or suspicion of a primary or secondary brain neoplasm that cannot be completely characterized on conventional imaging, or to differentiate between radiation necrosis and residual or recurrent brain tumor, or to assess for residual/recurrent brain tumor following treatment or therapy (191.0-191.9, 198.3, 225.0, 237.5, 239.6);
• To assess evidence or suspicion of inborn errors of metabolism, including but not limited to leukoencephalopathies of childhood.

Services that do not meet the medical necessity criteria on this policy will be denied as not medically necessary. A participating, preferred or network 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 should be maintained in the provider's records.

Description

Magnetic resonance spectroscopy (MRS) is a noninvasive imaging technique that identifies and quantifies different biochemical molecular structures and concentrations. The principles of MRS are similar to those of MRI because both imaging modalities use magnetic fields to generate an energy exchange between these external magnetic fields and charged subatomic particles within atoms to produce radiofrequency signals. 

MRS can be performed on commercially available MRI scanners with the aid of specialized computer software programs. Using complex mathematical algorithms, the computer software translates the radiofrequency signals into an anatomic image by assigning different gray values based on the strength of the emitted signal. While MRI provides a visual image of an anatomic structure, MRS detects the chemical composition of the scanned tissue.

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.

Under the Federal Employee Program, all services that utilize FDA-approved drugs, devices, or biological products are eligible when intended for the treatment of a serious or life-threatening condition and when medically necessary and appropriate for the patient’s condition.

National Blue Cross Blue Shield Association TEC Bulletin, Vol. 18, No. 1, June 2003

National Blue Cross Blue Shield Association Medical Policy 6.01.24

Magnetic Resonance Spectroscopy in Medicine: Clinical Impact, Progress in Nuclear Magnetic Resonance Spectroscopy, January 2002

Proton Nuclear Magnetic Resonance Spectroscopy of Body Fluids in the Field of Inborn Errors of Metabolism, Annals of Clinical Biochemistry, January 2003

Hydrogen Magnetic Resonance Spectroscopy in Alzheimer’s Disease, The Lancet Neurology, Vol. 1, No. 2, June 2002

Cardiac Magnetic Resonance Spectroscopy, Current Cardiology Reports, Vol. 5, January 2003

Centers for Medicare and Medicaid Services National Coverage Analysis on Magnetic Resonance Spectroscopy for Brain Tumors (#CAG-00141N)

The American College of Radiology’s Standard for the Performance and Interpretation of Magnetic Resonance Spectroscopy of the Brain, effective January 2003

Hwang YF, Huang TY, Hwang SL, Kwan AL, Howng SL. Differentiation Among Metastatic Brain Tumors, Radiation Necrosis, and Brain Abscesses Using Proton Magnetic Resonance Spectroscopy. Kaohsiung J Med Sci.2004;20(9):437-442.

Gropman AL. Expanding the Diagnostic and Research Toolbox for Inborn Errors of Metabolism: The Role of Magnetic Resonance Spectroscopy. Mol Gen Metab. 2005;86:2-9.

Delorme S, Weber MA. Applications of MRS in the Evaluation of Focal Malignant Brain Lesions. Cancer Imaging. 2006;6:95-99.

Shi-jun QIU, Zhang X, Zhang Y, Jiang M. Proton Magnetic Resonance Spectroscopy for Radiation Encephalopathy Induced by Radiotherapy for Nasopharyngeal Carcinoma. J South Med Univ. 2007;27(3):241-246. 

Tran T, Ross B, Lin A. Magnetic Resonance Spectroscopy in Neurological Diagnosis. Neurol Clin. 2008;27:21-60.

Xu V, Chan H, Lin A, Sailasuta N, et al. MR Spectroscopy in Diagnosis and Neurological Decision-Making. Semin Neurol. 2008;28:407-422.