Using our previously developed nuclear magnetic resonance imaging equipment, the dependence of the signal-to-noise ratio and radio frequency power deposition in patients, as a function of static field strength, has been investigated, in order to elucidate further the factors influencing the choice of a field strength for clinical imaging. It has been found that power deposition in the torso is reduced by a factor of between 1.5 and 2.5 (depending on patient build) if the irradiating field is applied laterally, as opposed to anterior-posterior, and the signal-to-noise ratio dependence has been shown to be in good agreement with a previously developed theory. Quadrature coil development has progressed well for imaging and for spectroscopy. Improvements have been made, with the aid of pieces of steel, to the homogeneity of the clinical imaging instrument.
