MALDI-IMS images of kidney sections from 28-day-old mice show the distribution and relative abudnace of ions with m/z 888.5561, 888.5709, and 888.6267. The abundance of each is indicated by a heatmap. Based on accurate mass, the peaks at m/z 888.5561 and 888.5709 correspond to C13 isotopes of phospholipids (PI(36:4) and PI(36:3), while m/z 888.6267 corresponds to the species of interest, i.e. SulfoHexCer(18:2/24:0). In contrast to the sulfatide, the two phospholipids were present at similar levels in the wild-type and Alport kidneys of 28-day old mice. High mass accuracy is necessary to separate near isobaric lipid species.