Incorporating Spatial and Spectral Saturation Modules Into MR Fingerprinting

Abstract

In this work, we introduce spatial and chemical saturation options for artefact reduction in magnetic resonance fingerprinting (MRF) and assess their impact on T1 and T2 mapping accuracy. An existing radial MRF pulse sequence was modified to enable spatial and chemical saturation. Phantom experiments were performed to demonstrate flow artefact reduction and evaluate the accuracy of the T1 and T2 maps. As an in vivo demonstration, MRF of the prostate was performed on an asymptomatic volunteer using saturation modules to reduce flow-related artefacts. T1, T2 and B1+ maps obtained with and without saturation modules were compared. Application of spatial saturation in prostate MRF reduced streaking artefacts from the femoral vessels. When saturation is enabled T1 accuracy is preserved, and T2 accuracy remains acceptable up to approximately 100 ms. Chemical and spatial saturation can be incorporated into MRF sequences with limited impact on T1 accuracy. Further sequence optimisation may be needed to accurately estimate long T2 components. Spatial saturation modules have potential in prostate MRF applications as a means to reduce flow-related artefacts.