Three-dimensional inversion recovery manganese-enhanced MRI of mouse brain using super-resolution reconstruction to visualize nuclei involved in higher brain function.

NMR Biomed. 2014 Jul;27(7):749-59. doi: 10.1002/nbm.3108. Epub 2014 May 10. Poole DS, Plenge E, Poot DH, Lakke EA, Niessen WJ, Meijering E, van der Weerd L. In this paper, they wanted to look at a different way of processing MRI images (inversion recovery spin echo (IR-SE), which can give better contrast than gradient echo (GE) imaging) to see if it could improve upon current MEMRI techniques. Since IR-SE tends to have lower resolution than would be really useful for an in vivo study, they wanted to merge multiple images taken at different angles to produce a super-resolution reconstruction that would give the resolution necessary to resolve functional regions of brain tissue. To do this SRR IR-SE MEMRI study, they started with two mice that received 300mg/kg MnCl2 over 8 days via subcutaneous osmotic minipump. They imaged the brains under both GE and SRR IR-SE and compared results for a lot of regions of the brain (including such favorites as PAG, PVN, and IC). The results of the comparison were kind of a 50/50 toss-up. Some regions could only be seen by GE, others could only be seen by SRR IR-SE, and some regions were just better visualized with one technique than the other. However, this study was all just about imaging contrast, and none of it was looking at functional changes (or at least not looking at intentional functional changes). It would be interesting to see them compare techniques in a region that had similar results with the two techniques, but do it AFTER causing an activity-dependent change in Mn uptake. I'll take a wild guess and say that they're probably already working on this. -DH