Claudiu Schirda1,2, Alexey Samsonov3, Jennifer L. Cox1,2, Robert Zivadinov1,2
1Buffalo Neuroimaging Analysis Center, Buffalo, NY, USA; 2Department of Neurology, The Jacobs Neurological Institute, SUNY Buffalo, Buffalo, NY, USA; 3Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA
Typical magnetization transfer (MT) techniques use a pair of sequences, with and without the MT pulse, and an MT Ratio (MTR) is calculated. This ratio is sensitive to the macromolecular content but it also depends on the T1 relaxation properties of the tissue. Quantitative Magnetization Transfer Imaging (qMTI) removes this drawback, by measuring and accounting for the T1 relaxation effect. However, at higher magnetic fields, due to the quadratic increase with B0 in RF power deposited by the MT pulse, SAR becomes an important limitation. We demonstrate the design of a 3T qMTI protocol compatible with the First Level SAR limit.