Reduction of flow artifacts in NMR diffusion imaging using view-angle tilted line-integral projection reconstruction

Abstract

Most diffusion imaging techniques employ strong diffusion gradient pulses of a long duration to obtain strong signal attenuation by the diffusion effect. However, these types of strong and long gradient pulses make the resultant images extremely sensitive to fluctuating flows such as the pulsatile blood or CSF flow. Fourier imaging, with which most current NMR imagings are performed, is especially sensitive to the fluctuating flow and the images are usually obscured by severe flow artifacts which are smeared in the coding direction. In this paper, we have proposed a new method which uses Line-integral Projection Reconstruction (LPR) imaging method could be used for the reduction of flow artifacts in NMR diffusion imaging. Through the experiments with phantoms and volunteers, it was verified that the proposed technique could successfully reduce the flow artifacts in diffusion imaging where large diffusion gradient pulses often obscure the resultant diffusion images. Furthermore, the inhomogeneity artifacts due to the suscaptibility and chemical shift in LPR imaging are corrected by applying the view angle tilting technique.