冠脉造影图像序列的时空滤波

为了降低冠脉造影图像的噪声、提高冠心病临床诊断的准确率,达到低X-射线辐射剂量的前提下获得高质量图像的临床应用目的,提出一种冠脉造影图像序列的时空滤波方法。将小波降噪中的阈值降噪思想引入到快速离散正交S变换(FDOST)中,提出了基于FDOST的软阈值降噪算法对冠脉造影图像进行空域滤波;使用小波降噪对冠脉造影图像序列进行时域滤波,充分利用小波降噪的时间平滑性;加入预处理环节,使用海森矩阵增强冠脉造影图像中的线状结构。仿真及实验结果表明了降噪后的图像信噪比和对比度相比原图像大幅提高,说明了该方法适用于低剂量辐射下的冠脉造影图像序列降噪。

Spatial-temporal filtering for coronary angiography image sequence

In order to reduce the noise of coronary angiography image sequence, enhance the diagnostic accuracy for coronary heart disease, and eventually acquire superior image quality under low X-ray dose, a method of spatial-temporal filtering for coronary angiography images was proposed. By introducing the idea of threshold noising in wavelet denoising into the Fast Discrete Orthonormal Stockwell Transform (FDOST), a soft-threshold denoising algorithm based on FDOST was proposed for the spatial denoising of coronary angiography images. The conventional wavelet denoising was used for temporal denoising of coronary angiography images, taking advantage of its time smoothing feature. Hessian matrix was used in pre-processing to track the line-like structure of coronary angiography images. The simulation and experimental results show that the signal-to-noise ratio and contrast-to-noise ratio of the denoised images are improved significantly compared with the original image, and the proposed method is suitable for the denoising of low-dose coronary angiography image sequence.