基于图像加权的多能光子计数X线CT全能谱图像重建改进方法

发布时间：2018-11-11 16:47

【摘要】：为了提高基于图像加权的多能光子计数X线CT全能谱重建图像的质量,提出了一种图像重建改进方法.首先,对每个能量段的投影数据采用最大后验概率(MAP)统计重建算法进行图像重建;然后,对各能量段图像进行优化加权求和,获得全能谱图像.仿真实验结果表明,MAP统计重建算法可显著提高全能谱重建图像的对比噪声比(CNR).与滤波反投影算法相比,当能量段数分别为2,4,6,9时,MAP统计重建算法使得钙图像的CNR分别提高659.7%,643.4%,621.2%,586.1%,碘图像的CNR分别提高663.8%,648.6%,635.1%,600.9%,软组织图像的CNR分别提高596.2%,638.5%,592.6%,596.3%;与能量积分法相比,当能量段数分别为2,4,6,9时,M AP统计重建算法使得钙图像的CNR分别提高43.3%,49.1%,49.3%,44.5%,碘图像的CNR分别提高43.2%,45.7%,45.7%,40.2%,软组织图像的CNR分别提高21.5%,28.9%,25.5%,26.2%.
[Abstract]:In order to improve the quality of image reconstruction based on image weighted multi-energy photon counting X-ray CT omnipotent spectrum, an improved image reconstruction method is proposed. Firstly, the maximum posterior probability (MAP) statistical reconstruction algorithm is used to reconstruct the projection data of each energy segment, and then the weighted sum of each energy segment image is optimized to obtain the omnipotent spectral image. The simulation results show that the MAP statistical reconstruction algorithm can significantly improve the contrast noise ratio of the reconstructed image with full energy spectrum (CNR). Compared with the filtered backprojection algorithm, when the number of the energy segments is 2? 4? The CNR of soft tissue images increased 596.2 and 638.5and 592.6and 596.3respectively. Compared with the energy integration method, the CNR of calcium image was increased by 43.3% and 49.3%, respectively, when the number of energy segments was 2 ~ 4 ~ 6 and 9, M AP, respectively, and the CNR of iodine image was increased by 43.2 and 44.5, respectively, compared with the energy integration method, and the CNR of iodine image was increased by 43.2%, respectively. The CNR of the soft tissue images increased by 21.5and 28.9and 25.5and 26.2cm, respectively.
【作者单位】：南京航空航天大学核科学与工程系;
【基金】：国家自然科学基金资助项目(51575256) 中央高校基本科研业务费专项资金资助项目(NZ2016102)
【分类号】：TP391.41

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