Nejati Mansour, Pourghassem Hossein
Department of Electrical Engineering, Najafabad Branch, Islamic Azad University, 517, Najafabad, Isfahan, Iran.
J Med Syst. 2014 Feb;38(2):10. doi: 10.1007/s10916-014-0010-8. Epub 2014 Jan 28.
Digital subtraction angiography (DSA) is a widely used technique for visualization of vessel anatomy in diagnosis and treatment. However, due to unavoidable patient motions, both externally and internally, the subtracted angiography images often suffer from motion artifacts that adversely affect the quality of the medical diagnosis. To cope with this problem and improve the quality of DSA images, registration algorithms are often employed before subtraction. In this paper, a novel elastic registration algorithm for registration of digital X-ray angiography images, particularly for the coronary location, is proposed. This algorithm includes a multiresolution search strategy in which a global transformation is calculated iteratively based on local search in coarse and fine sub-image blocks. The local searches are accomplished in a differential multiscale framework which allows us to capture both large and small scale transformations. The local registration transformation also explicitly accounts for local variations in the image intensities which incorporated into our model as a change of local contrast and brightness. These local transformations are then smoothly interpolated using thin-plate spline interpolation function to obtain the global model. Experimental results with several clinical datasets demonstrate the effectiveness of our algorithm in motion artifact reduction.
数字减影血管造影（DSA）是一种在诊断和治疗中广泛用于可视化血管解剖结构的技术。然而，由于患者不可避免的外部和内部运动，减影后的血管造影图像经常受到运动伪影的影响，这对医学诊断质量产生不利影响。为了解决这个问题并提高DSA图像的质量，通常在减法之前采用配准算法。本文提出了一种用于数字X射线血管造影图像配准的新型弹性配准算法，特别是针对冠状动脉部位。该算法包括一种多分辨率搜索策略，其中基于粗、细子图像块中的局部搜索迭代计算全局变换。局部搜索在差分多尺度框架中完成，这使我们能够捕捉大尺度和小尺度变换。局部配准变换还明确考虑了图像强度的局部变化，这些变化作为局部对比度和亮度的变化纳入我们的模型。然后使用薄板样条插值函数对这些局部变换进行平滑插值，以获得全局模型。对几个临床数据集的实验结果证明了我们算法在减少运动伪影方面的有效性。
