High-resolution diffusion imaging using a radial turbo-spin-echo sequence:Implementation, eddy current compensation, and self-navigation

This work describes a segmented radial turbo-spin-echo technique (DW-rTSE) for high-resolution multislice diffusion-weighted imaging and quantitative ADC mapping. Diffusion-weighted images with an in-plane resolution of 700 m u m and almost free of bulk motion can be obtained in vivo without cardiac gating. However, eddy currents and pulsatile brain motion cause severe arti facts when strong diffusion weighting is applied. This work explains in det ail the artifacts in projection reconstruction (PR) imaging arising from ed dy currents and describes an effective eddy current compensation based on t he adjustment of gradient timing. Application of the diffusion gradients in all three orthogonal directions is possible without degradation of the ima ges due to eddy current artifacts, allowing studies of the diffusional anis otropy. Finally, a self-navigation approach is proposed to reduce residual nonrigid body motion artifacts. Five healthy volunteers were examined to sh ow the feasibility of this method. (C) 2000 Academic Press.