Correction of Eddy-Current Induced Phase Error in Diffusion-Weighted Imaging
Huang J, Zhu D
Michigan State University
The theoretical basis for measuring the spatial derivative of diffusivity of water diffusion in tissues has been established based on a newly derived theoretical relationship between the diffusion gradient and the image signal acquired with a diffusion-weighted spin-echo pulse sequence. The diffusion gradient is linearly related with the phase change of the signal with and without diffusion-encoding gradients (DEG). Measuring the diffusion gradient provides a means of delineating the interface between two tissues with different diffusion magnitudes. However, the eddy currect induced by DEG could cause a large phase error in diffusion-weighted phase images. In this paper, we present a method for measuring the eddy current and correcting the phase error introduced on diffusion-weighted phase images.