A cone beam computed tomography system with a horizontally disposed, cylindrical gantry and a method for its use are provided. The cylindrical gantry includes a rotatable cylindrical frame fixed to a support frame. A cone beam X-ray source and X-ray detector are mounted to the circumference of the cylindrical frame at diametrically opposed positions. The cylindrical frame is actuated to revolve the X-ray source-detector arrangement around a horizontal axis, thereby scanning a recumbent subject positioned in the aperture of the cylindrical frame.
