Finite RF Pulse Effects on Quantitative Magnetization Transfer Imaging Using Balanced SSFP

Monika Gloor¹, Klaus Scheffler¹, Oliver Bieri¹

It has recently been shown that the effect of finite RF pulses can lead to considerable balanced SSFP (bSSFP) signal modulations. As bSSFP-based quantitative magnetization transfer imaging (qMTI) uses RF pulse modifications, a correction for these effects has to be included. In this work, a modification to the two-pool bSSFP equation is presented and effects on the parameter maps are assessed in human brain. This finite RF pulse correction improves the fitting quality considerably and reduces the values of the bound pool fraction F, the exchange rate k_f and the transverse relaxation time of the free pool T_2,f by about 10%.