Experimental results with a whole body NMR-CT scanner using a resistive magnet.

ABSTRACT

A brief explanation is given on various advantageous features of NMR imaging methods for practical diagnostic purposes. A whole-body NMR-CT scanner utilizing a big resistive air-core magnet has been developed in cooperation with the Institute for Solid State Physics, University of Tokyo. This prototype NMR-CT scanner employs the projection-reconstruction-imaging method with a selective excitation technique for slicing. It can provide physicians with high quality proton NMR images within a practicable, acceptable short data-collection time. Typical NMR-CT images of healthy volunteers and patients were obtained in the experiments using this device, and are presented here. Although the images mainly reflect the hydrogen nucleus concentrations of the subjects, they are strongly affected by relaxation times T1 and T2 and also by the the subjects' internal and external bodily activities. The effects of various NMR parameters in the reconstructed images are analyzed and examples showing these parameter effects are demonstrated. Another advantage of NMR imaging shown here, is a sagittal image of a human body, which is difficult to obtain by using an X-ray CT scanner.