3D positron emission tomography: preliminary results

Abstract

Quantitative radionuclide imaging has been a principal objective of most groups working with emission tomography. Positron emission tomography (PET) has been shown to be capable of providing quantitative images (Beller et al, 1982; Bergstrom et al, 1983; Beaney, 1984) which have contributed much to the understanding of cerebral and myocardial disease. Recently we have shown how a low cost prototype multiwire proportional chamber (MWPC) positron camera can produce longitudinal tomograms from limited-angle data acquisition via large area detectors (Ott et al, 1983; Flower et al, 1984). These tomograms were essentially qualitative in nature but provided enhanced image contrast when compared with conventional planar scintigraphy. In this paper we describe preliminary results of multiprojection acquisitions performed with the same detector providing 3D volume images. These images are intrinsically quantitative in nature and provide high-resolution, multipleslice tomograms of the object being imaged. Two examples of the clinical utilisation of these quantitative measurements of the uptake of radiopharmaceuticals in vivo are briefly described. The prototype MWPC positron camera has been extensively described elsewhere (Bateman et al, 1984). In previous studies, images were obtained without detector rotation because the design of this prototype precluded such motion. In order to obtain multiview acquisitions, a special chair was designed to enable patients or phantoms to be rotated within the field of view of the camera.