Enhanced 3-D reconstruction in NMR Fresnel diffractive imaging technique

ABSTRACT Enhanced 3-D reconstruction in NMR diffractive imaging technique which is a new approach to MR angiography,has been investigated. The expression of NMR signals obtained in the NMR diffractive imaging technique is similar to the equation for Fresnel diffraction in light waves or sound waves. Therefore, it is possible to reconstruct images focusing on optional plane in the depth direction using the data scanned two-dimensionally. However blurred image components out of focal-plane superimpose on the focal-plane image and the spatial resolution in the longitudinal direction is degraded. We have developed a new algorithm by which blurred image components are effectively removed. These studies demonstrate the possibility of the proposed method as a fast imaging technique for MR angiography. Keywords: MRI, angiography, high-speed imaging, Fresnel diffraction, maximum-likelihood 1. INTRODUCTION Angiographic imaging is widely used for clinical diagnosis. However, the use of Magnetic Resonance (MR) angiography to collect three-dimensional data is a time consuming process. Decreasing the data acquisition time will therefore reduce the burden on patients and increase patient throughput. In order to reduce the examination time required for MR angiography, we have been studying the utilization of the NMR Fresnel diffractive imaging technique