Magnetic Resonance Spectroscopy (MRS) measures in vivo concentrations of specific metabolites within a pre-determined volume of brain tissue. Using this information, MRS could potentially assist in the diagnosis of space occupying lesions in the brain.

The use of MRS is currently subject to a national noncoverage determination (Coverage Issues Manual Section 50-13).

On August 8, 2002 the American College of Radiology formally requested a National Coverage Determination (NCD) be made for MRS for the following indications:

Download Technology Assessment [PDF, 739KB].

For patients presenting with signs or symptoms of a space-occupying brain lesion:

1. For what metabolic profiles does the yield of MRS provide equivalent, complementary, or more accurate diagnostic information for (i) initial diagnosis, (ii) recurrence, or (iii) assessing therapy than
   • Brain biopsy
   • Conventional anatomic imaging studies
   • MRS + conventional anatomic imaging studies vs. brain biopsy

2. Does the use of MRS lead to an improved net health outcome by
   • Avoiding unnecessary biopsy
   • Obtaining appropriate biopsy, from appropriate location
   • Directing biopsy to an appropriate location
   • Receiving appropriate treatment
   • Avoiding an inappropriate treatment

3. Are voxel positions and operator error important factors in obtaining diagnostic images? If so, how do they impact MRS accuracy?