MPF Map (IMAGE)
Caption
The scheme demonstrating how an MPF map is computed from source MR images. Imaging protocol includes three gradient-echo images with variable flip angles, a gradient-echo image with off-resonance radiofrequency saturation enabling the magnetization transfer effect (MT-weighted image), and a reference image that is a similar gradient-echo image obtained without saturation. Additionally, an MR imager produces maps of the main magnetic field (B0) and radiofrequency field (B1), which are used to correct errors caused by imperfectness of imager's hardware. MPF maps are computed voxel-by-voxel in two steps, (A) and (B), using special software developed by the authors. During the first step (A), a map of the longitudinal relaxation rate (R1) is generated as described in the literature. This map along with an MT-weighted image and a reference image are used to compute an MPF map in the second step (B) based on an iterative algorithm recently described by the authors.
Credit
Radiological Society of North America
Usage Restrictions
May use with credit
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Licensed content