Current computed tomography (CT) scanners rotate fast to reduce motion artifact. X-ray tube must work in a high power to make the image clear under short exposure time. However, the life span of such a tube may be shortened. In this paper, we propose a novel double sources CT imaging system, which puts two of the same X-ray sources closely with each other. The system is different from current dual source CT with orthogonal X-ray sources. In our system, each projection is taken twice by these two sources to enhance the exposure value and then recovered to a single source projection for image reconstruction. The proposed system can work like normal single source CT system, while halving down the working power for each tube. 1. Introduction Current computed tomography (CT) scanners acquire multiple projection images (~1000 frames) [1, 2]. A more powerful X-ray tube could emit more X-ray photons during one exposure frame and then cost less time to ensure constant exposure dose. Twice the power gives the possibility of increasing the scanning speed. However, the cathode filament electric current must be doubled to ensure emitting twice the number of electrons, which is harmful to the lifetime of the cathode filament and the positive plate. Zhang et al. [3–6] proposed a multiplexing radiography technology based on carbon nanotube field emission, which is an effective method to gather X-ray radiation from more than one tube to enhance the exposure rate in one frame. In this case, the X-ray sources must be modulated easily. Otherwise, the maximum tube voltage of these sources is limited by current technology. In this paper, a novel CT imaging system is developed by placing two of the same X-ray tubes close to each other, along with a common detector. The system is different from current dual source CT system, where two sets of tube detectors are placed orthogonally [7–9]. In this system, the detector detects X-rays coming from two sources simultaneously. Two sources working together can make the exposure rate the same as a single source with half the exposure time. In the following sections, first we describe the structure of adjacent double X-ray sources and then propose a method to separate the overlapped projections for image reconstruction. For demonstration, fan-beam data acquisition and image reconstruction are presented, but the method can be easily extended to cone beam image reconstruction. Lastly, we discuss the potential benefits and limitations of the proposed method. 2. Materials and Methods 2.1. CT System with Adjacent Double X-Ray Sources The
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