Phase Delay and Attenuation Corrections in Fourier Transform Nmr Tomographic Imaging

Abstract

Applications of Fourier transform Nuclear Magnetic Resonance(NMR) to the field of tomographic imaging have become one of the important areas in biomedical imaging. NMR tomography, however, is low sensitivity imaging technique and the sensitivity is closely related to the static magnetic field strength applied to the object. Since the SNR (signal to noise ratio) of NMR imaging is proportional to Ho3/2, a higher magnetic field is a most desirable feature in NMR imaging. For a higher magnetic field, however, the frequency of r.f. signals for both excitation and detection is higher, which results in several undesirable effects such as phase delay and attenuation in the object. In this paper, we have proposed phase and attenuation dependent artifact correction based on the solution of the wave equation for a simple cylindrical model. Results of computer simulations and experiments are demonstrated.