Development of digital substraction angiography

Digital subtraction angiography (DSA) is one of the most important examinations in the

diagnosis and treatment of blood vessels. The radiation dose can be reduced using this examination because the vessels are visualized clearly; however, it is very difficult to apply the DSA technique to the coronary arteries because of the severe motion artifacts caused by cardiac motion and respiration.Myerowitz and his team reported that the coronary arteries are difficult to visualize using intravenous DSA because of their small size, rapid movement, and overlying structures. Therefore, many techniques have been studied to improve DSA image quality.Bentoutou and his team used a template-matching technique and 3D space motion detection for improving the accuracy of registration. A warping technique for the mask frame was used in a report by Meijering and his team with the aim of reducing motion artifacts. These techniques require a relatively long computation time. Therefore, it would be difficult to apply these techniques clinically because most of them do not enable real-time image processing. They propose a simple but effective technique for reducing motion artifacts in DSA. This method will be useful in the clinical environment because It enables real-time processing. In the present study, the average time taken to create DSA images of the coronary artery were 0.03 s per frame, without any special hardware board. In addition, this method can be performed by a commercially available stand-alone PC. Our DSA technique is easily installed into catheterization laboratories in hospitals. The results of subjective and objective evaluation showed that motion artifacts in DSA images were effectively reduced using our method. Because the average standard deviation of the pixel value of DSA images obtained using the new technique was 2.36 less than that of the conventional DSA images, motion artifacts caused by rapid movement were decreased. Therefore, this method will be useful in cardiologists’ decision making, especially for the peripheral blood vessels.