迭代重建算法前瞻性心电门控大螺距肺动脉双源CT成像的图像质量

Image quality of prospectively ECG-triggered high-pitch dual source CT using iterative reconstruction in pulmonary angiography

目的与滤波反投影(FBP)算法比较,探讨基于原始数据的迭代重建(SAFIRE)算法大螺距肺动脉双源CT(DSCT)成像的图像质量。方法对临床怀疑肺栓塞的69例患者行前瞻性心电门控大螺距肺动脉CT扫描,分别采用SAFIRE和FBP算法进行图像重建,比较两种重建算法的肺动脉CT图像质量、噪声、SNR和CNR。结果 SAFIRE算法图像的肺动脉CT图像质量显著优于FBP算法[图像质量评分分别为(1.28±0.36)分和(1.99±0.56)分,P<0.001];SAFIRE算法的噪声显著低于FBP算法[分别为(14.60±2.11)HU和(18.52±2.65)HU,P<0.001];SAFIRE算法的SNR和CNR显著高于FBP算法(SNR分别为26.57±4.99和20.23±3.94,P<0.001;CNR分别为23.41±4.58和17.77±3.62,P<0.001)。结论前瞻性心电门控大螺距肺动脉DSCT成像时,与FBP算法相比,SAFIRE算法的肺动脉CT图像噪声更低,图像质量更高,显示肺动脉细小分支更佳。

Objective To evaluate the image quality of prospectively ECG-triggered high-pitch dual-source CT （DSCT） in pulmonary angiography using sinogram affirmed iterative reconstruction （SAFIRE） compared with filtered back projection （FBP）. Methods Totally 69 patients with suspected pulmonary embolism underwent prospectively ECG-triggered high-pitch DSCT in pulmonary angiography. The images were reconstructed with SAFIRE and FBP. Image quality, image noise, SNR and CNR were compared between the two methods. Results Image quality of SAHRE was significantly better than FBP （image quality scores was 1.28±0.36 and 1.99±0.56, P〈0. 001）. The image noise of SAFIRE was signifi-cantly lower than FBP （image noise was [14.60 ± 2.11] HU and [-18.52 ± 2.65] HU, P〈0. 001）. SNR and CNR of SAFIRE were significantly higher than FBP （SNR was 26.57±4.99 vs 20.23±3.94, P〈0. 001; CNR was 23.41±4.58 vs 17.77±3.62, P〈0. 001）. Conclusion Compared with FBP, prospectively ECG-triggered high-pitch DSCT pulmonary angiography using SAFIRE can significantly reduce image noise and improve image quality, especially for displaying subdi- vision arteries.