Single-shot diffusion-weighted trace imaging on a clinical scanner.

The single-shot trace-weighted acquisition scheme for isotropic diffusion imaging suggested by Mori and van Zijl (Magn. Reson. Med. 33, 41-52 (1995)) was implemented on a clinical scanner in combination with echo-planar imaging. The results on phantoms and seven volunteers show that good-quality multiplanar isotropic diffusion-weighted images can be obtained within seconds and absolute Dav images within 10-40 s, depending on the number of gradient strengths used. However, care has to be taken in using this type of multi-bipolar-gradient sequence to avoid measurement of artifactual diffusion constants due to background gradient interference. It is outlined how to test for this interference and how to optimize for the correct experiment.