First Clinical Experience on Ultra-High Field MRI in Patients with Multiple Sclerosis: Comparison of 1.5 T and 7.0 T

Purpose: The purpose of this study was to investigate the potential of high resolution imaging of MS lesions in vivo comparing 7 T with conventional 1.5 T in detecting white and gray matter lesions.

Materials and Methods: Twelve patients with clinically definite relapsing remitting MS (mDD 5 years, mEDSS 2.8) were scanned on a 7 T whole-body scanner (Magnetom 7 T, Siemens) with a 8-channel phased-array, transmit receive head coil (Rapid Biomedical GmbH, Würzburg, Germany) and on a 1.5 T Avanto (Siemens) with a 12-channel phased array head coil. The imaging protocol consisted of high-resolution axial PD + T2-TSE, T2*-GRE, slice thickness 2mm, Matrix 512×384 and sagittal T1-weighted 3D-MPRAGE, Matrix 512×384, 0.6×0.5×0.6mm.

Results: The sequence parameters at 7 T had to be modified due to SAR restrictions but we were able to keep pulse sequence parameters equivalent to the imaging protocols at 1.5 T. White matter lesions were better detected and delineated from adjacent structures at 7 T compared to 1.5 T. 7 T revealed on T2*-GRE the perivascular migration of white matter lesions as well as a multilayer structure in lesions larger than 10mm. Due to the higher resolution it was possible to differentiate between juxtacortical white matter lesions and cortical lesions.

Conclusion: Ultra-high field imaging of MS patients at 7 T was well tolerated and provided better visualisation of MS lesions in the grey matter and better demonstrated structural abnormalities within the MS lesion itself.