[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.
Takahashi
Mitsuyuki
M
Department of Radiology, Federation of National Public Service and Affiliated Personnel Mutual Aid Associations, Yokohama Sakae Kyousai Hospital.
Ogura
Akio
A
Ozaki
Masanori
M
Muro
Isao
I
Doi
Tsukasa
T
Miyati
Tosiaki
T
Tanji
Hajime
H
Takahashi
Junji
J
Takizawa
Osamu
O
D038524:Diffusion Magnetic Resonance Imaging; D017352:Echo-Planar Imaging