Method and apparatus for mounting the detector array of a CT scanner to a radiation therapy simulator

An apparatus for selectively positioning the x-ray detector array of an apparatus for acquiring CT scans in the field of x-ray radiation produced by a radiation therapy simulator comprised of an x-ray radiation source, on x-ray table and an image intensifier tube so that the simulator is capable of being used for both therapy planning and computed tomography scanning comprising:

• a tray for mounting over the image intensifier tube of the radiation therapy simulator;
• means mounted to said tray for selectively moving the detector array of an apparatus for acquiring CT scans from a first position in the tray outside of the field of x-ray radiation produced by the radiation source of the simulator for use of the simulator for treatment planning purposes to a second position in the tray within the field of x-ray radiation produced by the radiation source for use of the simulator as a CT scanner;
• and
• a cover for closing said tray to form a substantially closed box with a height dimension substantially smaller than the width and depth dimensions thereof for fitting over the image intensifier tube and under the x-ray table of the simulator, the portion of said cover above the image intensifier tube of the simulator being comprised of radiolucent material.