Correction and Normalization of Magnetization Transfer Ratio Maps for Quantitative Analysis

Steffen Volz¹, Ulrike Nth¹, Anna Rotarska-Jagiela², Ralf Deichmann¹

Imaging of the Magnetization Transfer Ratio (MTR) is of increasing interest in neuroimaging, yielding important information, e.g. about myelin integrity. However, a quantitative analysis is affected by B1 biased MTR values and high specific absorption rates may require a reduction of the saturation angle for individual subjects, impairing comparability of results in longitudinal studies. Purpose of this study was to determine calibration parameters to correct for B1 bias in MTR maps at 3 Tesla, and to test if MTR data acquired at reduced MT saturation angles can be normalized to allow for comparison with data acquired at the full angle.