xCAT: A mobile, flat-panel volumetric X-ray CT for head and neck imaging

This paper discusses the design and imaging capabilities of xCAT, a mobile CT scanner aimed specifically at assisting surgical procedures of head and neck and for use in intensive care units. A high degree of compactness and portability has been achieved by utilizing large area flat-panel detectors, cone-beam imaging geometry and by careful mechanical and electrical design of the scanner. The system is powered up from standard electrical wall outlet, but can also be operated from a battery backup power source if needed. Furthermore, the scanner uses a flat-panel receptor capable of acquisition in the so called dual-gain mode [1], which significantly extends the effective dynamic range of the detector. As a result, improvements in the soft-tissue imaging capabilities over most of the currently available flat-panel detector cone-beam CT scanners have been achieved. This paper will discuss the design, data processing chain, patient's dose and image quality metrics for this system. The first soft- tissue brain images of a living human subject obtained with this unit will also be presented.