The purpose of this presentation is to show how a commercially available spiral CT can be modified for use as the electro-mechanical scanner hardware for a prototype flat panel detector-based cone beam volume computed tomography (FPD-CBVCT) imaging system. FPD-CBVCT has the benefits of isotropic high resolution, low contrast sensitivity and 3D visualization. In contrast to spiral CT, which acquires a series of narrow slices, FPD-CBVCT acquires a full volume of data (limited by the cone angle and the FPD active area) in one <= 360° scan. Our goal is to use a GE HighSpeed Advantage (HSA) CT system as the basis for an FPD-CBVCT imaging prototype for performing phantom, animal and patient imaging studies. Specific electromechanical and radiographic subsystems to be controlled include: gantry rotation and tilt, patient table positioning, rotor control, mA control, the high frequency generator (kVp, exposure time, repetition rate) and image data acquisition. Also, a 2D full field FPD needs to replace the 1D detector, as well as the existing slit collimator needs to be retrofitted to a full field collimator to allow x-ray exposure over the entire active area of the FPD. In addition, x-ray projection data acquisition needs to be performed at >=30 fps. Power and communication signals to control modules on the rotating part of the gantry will be through integrated slip rings on the gantry. Through the synchronized control of the pulsed x-ray exposures, data acquisition, gantry rotation and tilt, as well as the position and translation speed of the patient table, the system will be able to achieve spiral cone beam and circle-plus-arc cone beam image acquisition protocols. Performance will be evaluated with optical encoders, standard dosimetry equipment and phantom studies.