Distortion in diffusion weighted imaging

The definitional equation of the distortion of echo planar imaging(EPI)was examined. We compared measured values with calculated values by using the definitional equation of the chemical shift of the EPI method that first composed the diffusion-weighted image, and examined the possibility of applying it to the distortion. The results showed that the chemical shift with the definitional equation and the measurement corresponded, and the correlation between the chemical shift and the distortion was acquired. Next, the distortion of each images that composed DWI with the increase and the sign acceptable method difference of b value. The difference in the distortion between each image has increased with the increase in b value. It was assumed that the influence of the eddy currents was due to the high motion probing gradient.