Stationary head CT scanner using CNT x-ray source arrays

X-ray Computed Tomography (CT) is an indispensable imaging modality in the diagnosis of traumatic brain injury and brain hemorrhage. While the technology and the associated system components have been refined over the last several decades, all modern CT systems still rely on the principle of rotating sources and detectors. The rotating gantry adds a high degree of complexity to the overall system design, and could be eliminated in favor of a configuration of stationary x-ray sources and detectors. Such a change could potentially enable CT systems to be better suited for austere environments. Furthermore, the image acquisition speed would no longer be limited by the maximum rotating speed of the gantry. Unfortunately, due to the size and bulk of existing commercial x-ray sources, such a configuration is impossible to build with a sufficient number of focal spots. Recently, carbon nanotube (CNT) x-ray source arrays have been used in various stationary imaging configurations to generate diagnostic quality tomosynthesis images in the fields of mammography, dentistry, and orthopedics. In this study, we present a potential stationary head CT (s-HCT) design which combines projection data from 3 separate but parallel imaging planes for a complete CT fan-beam reconstruction. The proposed scanner consists of 3 CNT x-ray source arrays with a large number distributed focal spots each, and an Electronic Control System (ECS) for high speed control of the x-ray exposure from each focal spot. The projection data was collected by an array of multi-row detectors. For this unique imaging configuration, a customized geometry calibration procedure was developed. A linear collimator was designed and constructed for the reduction of cone-angle scatter. Finally, volumetric CT slice data was acquired through z-axis translation of the imaging object.