Burst excitation for quantitative diffusion imaging with multiple b-values

A quantitative imaging sequence has been developed to exploit the intrinsic sensitivity of Burst NMR data to molecular diffusion. In the scan time of a single spin echo experiment, it is possible to acquire many images of the same slice, with a different T2 and diffusion weighting. Under favorable conditions, it is possible to obtain both the diffusion coefficient and T2 from the same experiment; or, by correcting for T2 relaxation using a control image, more precise diffusion coefficients may be measured. The quantitative values in rat brain are in agreement with those from conventional experiments. The major gains of this method are the potentially reduced scan time, the higher number of acquired images corresponding to different diffusion weightings, the reduced sensitivity to inter-scan motion artifact and to local variations in magnetic susceptibility, and an automatic co-registration between T2 and diffusion images. Problems with the sequence include a lower signal-tonoise ratio than is achievable with diffusion-weighted spin-echo imaging, the limitation of measuring only in-plane components of diffusion and, at present, single-slice acquisition. Magn Reson Med 44:737‐745, 2000. © 2000 Wiley-Liss, Inc.