Influence of RF saturation parameters and CEST quantification metrics on human brain tumor contrast

Motivation: RF saturation parameters and CEST quantification metrics can greatly influence brain tumor contrast. Goal(s): To evaluate the effect of RF saturation parameters and different CEST calculation metrics on human brain tumors. Approach: CEST data was acquired from brain tumor patients with different RF saturation strengths and duty cycles (DC). Different quantification techniques including MTR asymmetry, apparent exchange-dependent relaxation (AREX), and extrapolated semisolid MT reference (EMR) were used for CEST quantification and compared. Results: A high RF saturation strength with 100% DC resulted in a good tumor contrast. EMR technique provided an appreciable tumor contrast among the CEST quantification techniques. Impact: This study sheds light on the influence of RF saturation parameters and CEST quantification metrics on brain tumor assessment. The choice of CEST metric must be carefully considered according to RF saturation parameter settings.