@article{oai:repo.qst.go.jp:00046235,
 author = {Joonas, Autio and Kershaw, Jeffrey and Shibata, Sayaka and Obata, Takayuki and Kanno, Iwao and Aoki, Ichio and ヨーナス オーティオ and Ｋｅｒｓｈａｗ Ｊｅｆｆｒｅｙ and 柴田 さやか and 小畠 隆行 and 菅野 巖 and 青木 伊知男},
 issue = {1},
 journal = {NeuroImage},
 month = {Apr},
 note = {Spin-echo diffusion-weighted functional MRI (DW-fMRI) was performed on a rat forepaw electrostimulation model at 7 T. This small animal model used electric (rather than visual) stimulation and allowed DW-fMRI experiments to be performed over a broader range of acquisition parameters than previous work on humans and cats. Resting state experiments with injections of ultra-small superparamagnetic iron oxide (USPIO) were also used to investigate the effects of gradient coupling on the signal change. The experiments were performed over five b-values (0, 200, 800, 1400 and 2000s/mm(2)) and three echo-times (30, 60 and 90 ms). Alterations to the stimulation-induced response with respect to TE and b-value were evaluated in two intervals: the positive stimulus-correlated response (5-20s after stimulus onset) and the post-stimulus undershoot (27-40s). There was no strong dependence of the signal change on b-value for any of the intervals or TEs. Similarly, changes to the apparent transverse relaxation rate showed no clear dependence on b-value. In contrast to previous DW-fMRI studies, the simplest explanation for the observed data is a single-compartment signal model with the functional signal changes probably corresponding to extravascular SE-BOLD. Experiments with USPIO suggested that at 7 T and within the range of parameters used, the influence of gradient coupling may be sufficient to explain minor DW-fMRI signal changes.},
 pages = {140--148},
 title = {High b-value diffusion-weighted fMRI in a rat forepaw electrostimulation model at 7T},
 volume = {57},
 year = {2011}
}