NMR 3D diffractive imaging technique

A new approach to MR angiography, the NMR diffractive imaging technique, has been investigated. The expression for 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 three-dimensional images by converting the NMR signal to a hologram and using an optical image processing system from the data scanned two-dimensionally. Moreover, an image focusing on an optional plane in the depth direction can be reconstructed numerically from the data by changing a distance parameter in the reconstruction step. Experiments were performed using an ultra-low-field MRI scanner to acquire two-dimensional data in the proposed technique. Even though a blurred image outside the focal plane is superimposed on the image in the focal plane, the three-dimensional distribution of the object can be recognized. This technique is expected to be useful in MR fast angiography.