Digital Subtraction Angiography Technique Based On The Flat Panel Imaging Device

In current clinic practice, Digital Subtraction Angiography (DSA) technique is an efficacious visualization tool for the blood vascular structures. Especially in recent years, Digital Subtraction Angiography technique gradually takes place of traditional film and image intensifier model DSA. And it becomes absolutely necessary tool in medical diagnosis. How to make subtraction more clear become of a research hotspot in the field of medical imaging in recently.The flat panel detector DSA is researched in this dissertation. The difference is compared with flat panel DSA and image intensifier DSA. By the experimental results, we can see that flat panel detector DSA has obvious advantage.In the study of DSA technique, the better image effect can use directly subtract method. But most of DSA image are affected by background organs in subtraction, so this paper use the logarithmic transformation subtraction method. This method makes the vascular image was subtracted more clearly. In the course of subtraction, the image appears artifacts because patient's human organs inevitable moving. In this thesis, image registration problem in DSA technique is discussed and a new image registration approach is used. Firstly, the evenly chosen small number of points on the vascular centerlines forms the control points set. Secondly, control points offset is calculated in the mask image. Finally, a smoothed thin-plate splines (TPS) interpolation function is used to conduct image warping towards the mask image based on the corresponding control point sets. The smoothed thin-plate splines interpolation function can control the warping and smooth degree by adjusting the smooth parameter. The experimental results show this method can make the mask image registration. At present, most DSA image follows DICOM 3.0 Standard. In this dissertation the DSA image is displayed by research DICOM Standard, and a DSA image display software is developed by VC++6.0 programming.The DSA technique can dynamically display the vascular flowing condition, clearly display lesions, improve diseases discover-rate and diagnostic accuracy, which can decrease the contrast agent using, improve operation safety and reduce operation cost. In a word, the DSA technique will have extensive appliance and wide prospect.