SIMULTANEOUS CT AND SPECT TOMOGRAPHY USING CZT DETECTORS

A method for simultaneous transmission x-ray computed tomography (CT) and single photon emission tomography (SPECT) comprises the steps of: injecting a subject with a tracer compound tagged with a &ggr;-ray emitting nuclide; directing an x-ray source toward the subject; rotating the x-ray source around the subject; emitting x-rays during the rotating step; rotating a cadmium zinc telluride (CZT) two-sided detector on an opposite side of the subject from the source; simultaneously detecting the position and energy of each pulsed x-ray and each emitted &ggr;-ray captured by the CZT detector; recording data for each position and each energy of each the captured x-ray and &ggr;-ray; and, creating CT and SPECT images from the recorded data. The transmitted energy levels of the x-rays lower are biased lower than energy levels of the &ggr;-rays. The x-ray source is operated in a continuous mode. The method can be implemented at ambient temperatures.