Elimination of Inflow Enhancement by Partial Pre-Saturation in RF Spoiled Imaging
نویسندگان
چکیده
Introduction: For RF-spoiled gradient echo imaging (ie SPGR, FLASH, T1-FFE), the combination of spoiling gradients and quadratic phase cycling eliminates net transverse magnetization within a voxel [1-4] to enable pure T1 contrast. Generally, many RF excitations are required to attain steady state magnetization levels. Therefore, when unsaturated spins are flowing into the imaging volume, inflow enhancement [5] occurs at entry slices of the slab, which can affect quantitative imaging such as in calculation of the arterial input function. We hypothesize that partial saturation of an outer slab could provide the desired longitudinal magnetization to avoid inflow effects with minimal artifacts. To test this, we investigate the complex magnetization of partially saturated flowing spins in an RF-spoiled gradient echo sequence using simulations, phantom and in vivo experiments.
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