| Cone beam CT is extremely important in the field of medical diagnosis,but conventional CT systems are bulky,heavy,and difficult to move.Therefore,the development of a dedicated lightweight cone beam CT imaging system has important practical value.Cone beam CT can also provide sub-millimeter resolution for high-quality diagnostic images of various diseases,with less radiation dose and shorter scanning time than traditional CT.Therefore,this paper develops a special lightweight cone beam CT imaging system for the special requirements of portability and high image resolution.The system adopts a layered structure,with the upper layer facing the user and the lower layer facing the hardware.The system includes hardware system and software system.After that,relevant control system performance evaluation experiments are carried out on this system.The main work of the paper is as follows:In terms of hardware system,it includes seven major hardware devices:X-ray source,detector,relay,beam limiter,motor,DAP and host computer.These seven hardware devices control different functions respectively.In order to reduce the exposure dose,the system adopts the pulsed X-ray emission mode,and implements strict timing synchronization control for X-ray tube exposure and detector information collection;each equipment cooperates,and finally the rotation control of the motor in the rack realizes 360℃.°full scan.In terms of software system,independent drivers are designed and implemented for seven hardware devices.Finally,QT is used to integrate them together to form a complete software system.The software system before integration can also realize the functional requirements of a single hardware.After integration,the software system can realize the complete scanning process of the cone beam CT scanning protocol,including pulsed exposure,360° rotating scanning,scanning data transmission and other functions.For the performance evaluation of the control system,the standard phantom Capton 500 was used to optimize the reconstruction algorithm,and the pig’s knuckle was used to simulate the human body for scanning.The control system of cone beam CT simultaneously realizes two schemes of image chain synchronization control:hardware control and software control.Experiments show that compared with software synchronization,hardware synchronization greatly reduces the X-ray irradiation time and the radiation received by the object,and at the same time produces a lower CPU occupancy rate and improves the performance of the imaging chain imaging system.Therefore,hardware control is safer and more practical than software control.Lightweight cone beam CT can provide more advanced imaging support for existing intensive care of the head,neck,limbs,trunk,and field shelters.The open structure design can also provide intraoperative navigation for operations including cranial,spinal,intensive care,trauma,orthopedic and vascular surgery. |
