多层螺旋CT回顾性心电门控肺重组的最佳时相研究

目的 评价多层螺旋CT回顾性重组肺影像的最佳R-R时相,探讨心电门控肺部扫描的可行性及合理的扫描方案. 资料与方法 对15例拟诊冠心病患者以相同参数行多层螺旋CT扫描后,利用回顾性心电门控重组10%、30%、45%、60%、75%、90% R-R 时相的横断面影像.范围包括自气管隆突至心尖的双侧肺,比较不同的R-R时相肺动脉层面、下肺静脉干层面、下肺基底段支气管开口层面、心尖层面影像,评价影像质量. 结果 各时相影像质量的综合评分差异有统计学意义(P<0.001).两两比较后发现75%时相与其他各组差异均有统计学意义(P<0.001).肺重组的最佳时相为75%的R-R时相. 结论 选择75%的R-R时相回顾性心电门控为最佳R-R时相重组肺可以最大限度地减轻心脏运动伪影对肺组织影像质量的影响,提高影像质量,在常规影像伪影较多时,可增加病变的信息量,减少假阳性的产生,提高诊断准确率.

The Study of Optimal R-R Phase Electrocardiographically gated Reconstructed Multi-slice Spiral CT in Pulmonary Fields

Objective To evaluate the optimal R-R phase of electrocardiographically(EEG)gated image reconstruction for mult-slice spiral CT(MSCT)pulmonary fields and to study the feasibility and the appropriate scan protocols retrospectively.Materials and MethodsA total of 15 patients with known or suspected coronary artery disease(CAD)were detected with retrospectively ECG gated MSCT during a single breath hold.Source images were reconstructed at the starting points of 10%,30%,45%,60%,75%,and 90% R-R intervals,including both of the lung fields from trachea eminence to apex cordis.The image quality of different level(including lung artery level,inferior lung vein and inferior basal bronchium)was evaluated.ResultsSignificant difference existed among those phases and lung fields were best visualized at 75% R-R phases.Conclusion The optimal R-R phase images can reduce the artifacts of cardiac motion and improve te ECG gated reconstruction image quality of the lung fields.