Focal white matter lesions (WML) of demyelination are the most readily detectable manifestation of multiple sclerosis at morphologic MRI. However, they represent only macroscopic tissue damage.
Therefore, they are unable to fully explain the topographic origin and severity of many clinical symptoms of multiple sclerosis, particularly in the progressive phase of the disease. Advanced imaging techniques have found a more subtle yet extensive pathologic manifestation in the normal-appearing white matter (NAWM) and the gray matter.
To date, most spectroscopic studies have been limited by low spatial resolution and small volume coverage (especially single-voxel studies). Nevertheless, they have assumed that the investigated volumes are globally representative. Furthermore, the investigation of cortical gray matter (CGM) has also been hampered.
Recent progress in 7.0-T free-induction decay (FID) MR spectroscopic imaging (MRSI) with matrix sizes of 100 × 100 reduces partial volume errors of previous studies and, as already shown, allows more accurate characterization of metabolic alterations in WML and within clinically attractive scan times of approximately 6 minutes. The researchers evaluate the ability of 7.0-T FID MRSI to depict and visualize pathologic manifestations in the NAWM and CGM in participants with multiple sclerosis and investigate their relationship to disability.