Ren Miaojian, Wang Qian, Yang Xin, Zhu Ming
Institute of Image Processing and Pattern Recognition, Shanghai Jiaotang University, Shanghai 200240, China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2010 Oct;27(5):1120-7.
In digital subtraction angiography (DSA), the contrast of the vessels is greatly improved with the injection of contrast medium. In addition, more clear vessels can be visualized by eliminating the images of non-vessel organs, and those images are called subtraction image or DSA. Therefore, DSA is of wide use for diagnosis of cardiovascular disease. Subtraction of images obtained before and after injection of contrast medium may create motion artifacts due to the aspiration of patients. In this regard, being motivated by the doctors' experience that the displacement of diaphragm can be used as the reference to measure the heart beat, we present a method to eliminate the motion artifacts. In our method, firstly, a set of DSA images are taken before injection of contrast medium, which are called "mask images"; and one image taken after injection of contrast is called "target image". Secondly, a "reference mask image" is assigned, which is one of "mask images"; "and the displacement of diaphragm from "reference mask image" to the other mask images and the target contrast image is measured. Thirdly, based on the measurement results, several candidate mask images in which the displacement is less than a threshold can be selected. At last, the optimization algorithm is applied on the selected images, and the corresponding mask image that has minimum motion artifact is retrieved.
在数字减影血管造影（DSA）中，通过注射造影剂可显著提高血管的对比度。此外，通过消除非血管器官的图像，可以看到更清晰的血管，这些图像被称为减影图像或DSA。因此，DSA在心血管疾病诊断中应用广泛。注射造影剂前后获取的图像相减可能会因患者呼吸而产生运动伪影。在这方面，受医生经验（即膈肌的位移可作为测量心跳的参考）的启发，我们提出了一种消除运动伪影的方法。在我们的方法中，首先，在注射造影剂之前拍摄一组DSA图像，这些图像被称为“蒙片图像”；注射造影剂后拍摄的一张图像被称为“目标图像”。其次，指定一幅“参考蒙片图像”，它是“蒙片图像”之一；测量从“参考蒙片图像”到其他蒙片图像以及目标造影图像的膈肌位移。第三，根据测量结果，可以选择位移小于阈值的几个候选蒙片图像。最后，对所选图像应用优化算法，检索出运动伪影最小的相应蒙片图像。
