Minimization of Post-Stimulus Undershoot in Heavily Diffusion-Weighted Functional Magnetic Resonance Imaging
Obata T, Tomiyasu M, Hirano Y, Nonaka H, Kashikura K, Ikehira H, Hirano M
National Institute of Radiological Sciences
To reveal relationship between post-stimulus undershoot in diffusion-weighted functional MRI (DWI) and slow return to baseline in ADC transient feature, we analyzed post-stimulus undershoot in heavily DWI (b=1400 s/mm2), and compared it with that in weakly DWI (b=200 s/mm2). The DWI (b=1400 s/mm2) transient feature showed minimization of the post-stimulus undershoot, significantly different from that in DWI (b=200 s/mm2). The same physiological mechanism might cause undershoot minimization in DWI (b=1400 s/mm2) response and a slow return in the ADC transient feature after stimulation.