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.