Fig. 1
From: Characterizing the neurological phenotype of the hyperinsulinism hyperammonemia syndrome
Overview of GluCEST acquisition and analysis. a GluCEST is measured on an axial slice at the level of the hippocampus using the same MRI acquisition protocol in nine HI/HA subjects and a reference population of ten healthy adults. Measurements are limited to a single slice (i.e., a single layer of voxels, or equivalently, pixels in 2D). The hippocampus was segmented using the ASHS pipeline in ITK-SNAP. A 3D render of the hippocampus of an example healthy reference adult (C006, see Additional file 1) is shown along with the 2D GluCEST slice of the same individual (note, the 3D render is used for visualization purposes only). b The GluCEST values within the hippocampus are overlaid on the subject’s T2 image from panel a. c The distribution of GluCEST values (top, histogram; bottom, ECDF plot) in each hippocampus is shown corresponding to the same subject of panels a and b. The solid vertical line represents the mean of all pixel values in the hippocampus, and the dashed vertical lines represent ± 1 SD. d Heatmap of GluCEST values are shown for all HI/HA subjects with interpretable MRI and a representative healthy reference subject (C010, see Additional file 1). GluCEST values for both the entire axial slice and within only the hippocampus are shown. Similar to the representative plots of panel c, the distribution of hippocampal GluCEST values is also shown. ASHS, Automatic Segmentation of Hippocampal Subfields; CEST, chemical exchange saturation transfer; ECDF, empirical cumulative density function; GluCEST, glutamate chemical exchange saturation transfer; HI/HA hyperinsulinism hyperammonemia syndrome; SD, standard deviation