中文摘要：

针对单光子发射断层成像技术中全局图像重建时间过长的问题,提出了局部重建的思想,同时为了提高局部重建图像的质量,需要在局部重建之前,对投影图像进行噪声去除.利用基于小波变换的复数改进二元萎缩相关去噪法,对噪声投影图进行处理,并利用局部重建算法进行图像的局部重建,在保留图像细节的同时,降低了图像噪声,缩短了重建时间.利用均方误差评价标准,对去噪结果进行评测,结果表明：在局部重建中,利用该方法进行去噪处理具有良好的效果.

英文摘要：

Local reconstruction algorithm has been proposed to reduce the reconstructing time in the single photon emission computer tomography （SPECT）.To improve the image quality,it is necessary to de-noise the projection image before reconstruction.Revised biva-shrinkage de-nosing based on wavelet transformation,which has a property of reserving detail information,is used to pre-treat the image.The mean square error （MSE）is adopted to evaluate the de-noising image of local reconstruction.The results show that wavelet based de-noising method is effective in local reconstruction algorithm.