Optimization of diffusion-tensor MR imaging data acquisition parameters for brain fiber tracking using parallel imaging at 3 T.

The purpose of this study was to optimize the parameters of diffusion-tensor magnetic resonance imaging (DT MRI) for brain fiber tracking using a slice thickness of 2 mm, a resolution advantage allowed by the high signal-to-noise ratio at 3 T, combined with an 8-channel phased-array head coil. The b-factor, number of motion probing gradient (MPG) directions, and number of averages were varied, and the results of brain fiber tracking for the pyramidal tract and trigeminal nerve were compared qualitatively and quantitatively. The DT MRI data sufficient for brain fiber tracking in healthy subjects can be obtained in <2 min with a 2-mm slice thickness, 700-s/mm2 b-factor, 6 MPG directions, and no averaging (number of averages=1).