[Influence exerted by MPG-directions on diffusion tensor imaging (DTI)].

When diffusion tensor was analyzed, increasing motion probing gradient (MPG) directions and increasing signal-to-noise ratio (SNR) as result might influence diffusion tensor calculation. This study determined that mean diffusivity (MD) and fractional anisotropy (FA) are calculated by changing MPG-directions or SNR in the volunteer. There were no statistically significant differences in MD, which is calculated from all scanning parameters (p>0.05). FA of the caudate nucleus was similar as well. However, there were statistically significant differences between FA calculated from 31 MPG-directions and from 13 MPG-directions or less for the frontal lobe and caudate nucleus (p<0.05). If SNR of a trace image is 30 or more, FA wasn't affected by SNR (p>0.05). To calculate FA, minimum MPG-directions that were not statistically different compared with 31 MPG-directions were 15 MPG-directions (p<0.05).