An attempt to understand why we measure longer relaxation times in quantitative muscle MRI using MRF than using conventional methods

Fast relaxation time quantification is important in dynamic muscle studies and can be achieved using Magnetic Resonance Fingerprinting (MRF). The T₂ values in muscle measured with MRF are consistently higher than those measured with the conventionally used multi-echo turbo-spin-echo (MSE) method, while T₁ values are closer to reference measurements. We hypothesize that this increase can in part be attributed to an increased sensitivity of MRF to flow compared to MSE. In this work we test the sensitivity of MRF to flow in muscle by saturating a slab at different distances above the imaging slice for variable suppression of inflowing spins.