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

Most of the diffusion imaging techniques employ strong diffusion gradient pulses of long duration in order to achieve appreciable signal attenuation through the diffusion effect. However, these strong and long gradient pulses make the resultant images extremely sensitive to the motion or flow of the object. Fourier imaging, with which most of the current NMR imaging is performed, is especially sensitive to the fluctuating flow and the images are usually obscured by severe flow artifacts smeared in the phase-encoding direction. In this paper, we have proposed a diffusion imaging technique which reduces the flow artifacts by use of the line-integral projection reconstruction (LPR) imaging method. Furthermore, the inhomogeneity artifacts expected to occur in LPR imaging have been corrected by application of the view-angle tilting technique. The pulse sequence of the view-angle tilted LPR diffusion imaging is designed in such a way that it works for both isotropic and anisotropic diffusion. Experimental results are presented along with the experimental procedures.