FAST RADIAL IMAGING OF CIRCULAR AND SPHERICAL OBJECTS BY NMR

A family of fast NMR image processing techniques for the study of objects with circular or spherical symmetry is introduced. Radial information for circular objects is obtained by Abel inversion of a one-dimensional NMR image or, equivalently, Hankel transformation of the 1D time-domain NMR signal. Spherical objects may be radially resolved from a 1D image by applying two sequential Abel inversions, or in one simple differentiation step. In the presence of adequate signal-to-noise, all the image information is obtained in a single experimental interation, thus providing snapshot temporal resolution. The processing techniques, which we call radial imaging, are easy to implement and have modest computational and data storage requirements. The techniques are described and compared with conventional, i.e., Cartesian, imaging techniques, with the use of simulations and NMR data. Noise effects and the detection and handling of distortions from circular symmetry are also considered. © 1991.