Field Drift and fMRI

Some scanners suffer from rather large field drifts after fMRI acquisitions, due to heating of passive shims and other metal in the scanner.  We are working on the extent to which this impacts measurements. Dr Benjamin Glaubitz in Bochum acquired this data showing the dramatic field drift caused by a single 10-minute fMRI run. Gannet seems to do a reasonable job of correcting the drift (although whether it removes all the effects of the drift is not yet clear).

 Clearly there are some studies which require fMRI to be performed before GABA-MRS< but if you can avoid it, we'd suggest leaving fMRI (or DTI) until after the GABA scans.