NMR imaging aritfact correction and NMR instrumentation

Abstract

Application 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 $H_o^\frac{3}{2}$, 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. As related topics we have proposed phase delay and attenuation depended artifact correction based on the solution of the wave equation for a simple cylindrical coordinate model and then optimum field strength that gives maximum sensitivity is studied. Finally, a new parallel plate gradient coil system is proposed and analyzed for practical imaging facility.