Research On Image Acquisition Of Stationary Digital Breast Tomosynthesis Based On Amorphous Selenium Flat Panel Detector

Digital breast tomosynthesis(DBT)is an advanced application technology based on digital flat panel detector.It is a new type of tomography imaging technology combined with digital image processing technology based on traditional tomography.The stationary digital breast tomosynthesis(s-DBT)system is a digital breast tomosynthesis system based on multi-beam X-ray source array.The system with static imaging realized by static electrical scanning,the motion artifacts caused by rotation of X-ray source would effectively eliminated,the scanning time of imaging would also be reduced.The X-ray source based on carbon nanotube cathode has the advantages of high time resolution and programmable control.The emission control of multi-beam X-ray source is the key direction of research.The digital amorphous selenium flat panel detector is a type of direct conversion digital detector that converts X-rays directly into electrical signals with extremely high imaging resolution which is sufficient to meet the requirements of mammography.In this paper,we studied the development of the image acquisition software and image preprocessing methods for the stationary digital breast tomosynthesis system based on AXS-2430 amorphous selenium flat panel detector.In the Visual Studio 2010 software platform,MFC is used to develop the image acquisition software of the flat panel detector.In addition,the pulse parameters control software and control circuit of the arrayed multi-beam carbon nanotube X-ray source are designed.Finally,the developed image acquisition software and the corresponding control circuit were used to collect the phantom image of breast,and studied the image preprocessing method and result analysis.The mainly studies of this thesis including:(1)The structure and imaging principle of digital flat panel detector,the operation principle of X-ray source based on carbon nanotube cathode and the imaging principle of stationary digital breast tomosynthesis(s-DBT)system are introduced and analyzed respectively.Analyzing the performance of the current commercial flat panel detectors,made the choice of amorphous selenium flat panel detector as the imaging medium.(2)Developed the detector image acquisition software and pulse parameter control software based on MFC and integrated them,the software achieved the functions with image acquisition,image storage and real-time image display.Finally,the spatial resolution of the detector was measured and analyzed by line-pair card,which verifies the imaging performance of the detector.(3)Designed the parameter control circuit of the arrayed multi-beam X-ray source based on the minimum system of FPGA,experimental and analysis were done based on the design of the circuit combined with pulse parameter control software.Result shows that the control circuit meet the requirement of the design.(4)Based on the experimental imaging data,the image preprocessing of the projection image is studied,including image correction,window adjustment and DICOM conversion.The relatively better correcting algorithm is designed by comparing the noise eliminating results with different calibration methods.