@misc{oai:repo.qst.go.jp:00070237,
 author = {Kershaw, Jeffrey and Leuze, Christoph and Joonas, Autio and Shibata, Sayaka and Obata, Takayuki and Kanno, Iwao and Aoki, Ichio and Ｋｅｒｓｈａｗ Ｊｅｆｆｒｅｙ and ロイツェ クリストフ and ヨーナス オーティオ and 柴田 さやか and 小畠 隆行 and 菅野 巖 and 青木 伊知男},
 month = {Sep},
 note = {It has long been hypothesised that restricted (or hindered) motion of water molecules is responsible for the anisotropic image contrast in diffusion-tensor MRI, in particular in white matter. It has also been recognised that in that case, by varying the length or separation of the motion-probing gradients (MPGs), it should be possible to alter the contrast of in vivo images and thus common measures of diffusion anisotropy to probe tissue microstructure. Most previous efforts were unable to find in vivo evidence for the restricted-diffusion hypothesis (eg Clark1), but recent work using a technique that utilises rapidly oscillating MPGs added to a standard spin-echo sequence, has demonstrated some of the characteristics of restricted diffusion for in vitro samples, and normal and diseased rat brain2-4. However, the technique has never been applied to examine alterations to apparent diffusion anisotropy as the MPG frequency is increased (or, equivalently, the diffusion-time is decreased). In this study, an oscillating MPG sequence was applied to investigate changes to the apparent diffusion tensor, fractional anisotropy and mean diffusivity in rat cerebellum. The gradient frequencies were in the range 30-200 Hz and corresponded to effective diffusion times of 1-8 ms2.
The results clearly showed that the mean diffusivity increased with MPG frequency, which is a characteristic expected of the restricted/hindered diffusion model (see figure below). Other indices of diffusion anisotropy were also visibly altered by changes to the MPG frequency.
 Given sufficient gradient-set performance, it is anticipated that normal and pathological in vivo tissue structure can be probed with this technique to frequencies of at least 1-2 kHz., World  Molecular Imaging Congress 2010},
 title = {Apparent diffusion anisotropy in rat cerebellum is altered at short effective diffusion-times using oscillating-gradient diffusion-tensor MRI},
 year = {2010}
}