目的：比较滤波反投影（Filtered back projection，FBP）与迭代算法（Sinogram-affirmed iterative reconstruction，SAFIRE）的图像质量及左心室功能评价的准确性。材料与方法：纳入我院先后3天内行冠状动脉CT检查和心脏MR检查者82例为研究对象，分别采用FBP和SAFIRE重建系列图像。将82例按照体质量指数（BMI）分成A组（BMI≤24 kg/m2，共30例）和B组（BMI＞24 kg/m2，共52例），测量主动脉根部及皮下脂肪组织CT值及标准差，计算图像信噪比（SNR）和对比噪声（CNR），分别比较两个BMI组不同重建方法的图像质量。利用心功能分析软件测量两种重建图像的左心室舒张末期容积（EDV）、收缩末期容积（ESV）、每搏输出量（SV）和射血分数（EF），并以MRI心功能测量结果作为金标准，对比分析两种重建方法评价左心室功能的准确性。统计分析采用配对t检验和Pearson相关分析。结果：A组和B组SAFIRE重建图像噪声分别下降18.98%和17.40%，SNR和CNR分别提高23.99%、32.54%和22.07%、31.73%，差异均有显著的统计学意义（P＜0.001）。与MRI相比较，两种重建算法测得的左心室EDV、ESV、SV和EF值均无统计学差异（P＞0.05），经Pearson相关分析，两种重建方法与MRI的结果均具有相关性。结论：SAFIRE重建较FBP重建可提高图像质量。两组重建方法测量左心室功能与MRI均具有相关性，SAFIRE重建图像测量结果更为准确。
Abstract
Objective: To compare the image quality and the accuracy of contrast computed tomography(CT) for left ventricular function assessment between sinogram-affirmed iterative reconstruction(SAFIRE) and filtered back projection(FBP). Methods: A total of 82 patients prospectively underwent cardiac examination with Dual-source CT and MRI(as reference standard) within 3 days. All CT images were reconstructed with FBP and SAFIRE techniques, respectively. All patients were divided into group A(BMI≤24 kg/m2, n=30) and group B(BMI＞24 kg/m2, n=52). The CT values and standard deviations of aorta and subcutaneous fat tissue were measured and SNRs and CNRs were calculated. Image quality was assessed for both reconstruction techniques. From these two different reconstruction images, ESV, EDV, SV and EF were determined using the Simpson’s method and compared with MRI. Paired-t test and Pearson’s correlation were used for statistical analysis. Results: The image noises on SAFIRE images decreased by 18.98% and 17.40% and SNRs/CNRs increased by 23.99%/32.54%(group A) and 22.07%/31.73%(group B) compared with FBP images, respectively(all P<0.001). There was no significantly overestimation and underestimation of EDV, ESV, SV and EF by FBP and SAFIRE compared to MRI(all P>0.05), respectively. All LV function measurements of CT images showed statistically intraclass correlations with MRI. Conclusion: SAFIRE may improve image quality. LV function measurements acquired by SAFIRE and FBP image data sets all were statistically related to MRI. The LV function results derived by SAFIRE images were more accurate.
关键词
心室功能 /
左；体层摄影术 /
X线计算机；血管造影术
Key words
Ventricular function, left /
Tomography, X-ray computed /
Angiography
中图分类号：
Ｒ541
Ｒ814.42
Ｒ814.43
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基金
辽宁省自然科学基金资助项目（项目编号2014021072）。
