Optimization of fast acquisition methods for whole-brain relative cerebralblood volume (rCBV) mapping with susceptibility contrast agents

Fast gradient-echo magnetic resonance scan techniques with spiral and recti linear (echoplanar) k-space trajectories were optimized to perform! bolus-t racking studies of human brain. Cerebral hemodynamics were studied with ful l brain coverage, a spatial resolution of 4 mm, and a temporal resolution o f 2 seconds. The sensitivity of the techniques to detect image signal-inten sity changes during the first pass of the contrast agent was studied at a r ange of TEs using dedicated experiments. For single-shot versions of spiral scanning and echoplanar imaging techniques with a 0.1-mmol/kg injection of gadolinium diethylenetriamine pentaacetic acid using a mechanical injector at 10 mL/sec under 1.5 T, the maximum sensitivity was obtained at TEs betw een 35 and 45 msec, At TEs less than 35 msec, signal-intensity artifacts we re observed in the images. Analysis of the point-spread function revealed t hat susceptibility changes induced by the contrast agent can result in sign al shifts to neighboring voxels, These artifacts are attributed to suscepti bility-related signal changes during the acquisition window. J, Magn, Reson , Imaging 1999;9:233-239. (C) 1999 Wiley-Liss, Inc.