Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC 29425, United States.
Eur J Radiol. 2012 Apr;81(4):e598-604. doi: 10.1016/j.ejrad.2011.07.001. Epub 2011 Aug 9.
To prospectively evaluate the accuracy of left and right ventricular function and myocardial mass measurements based on a dual-step, low radiation dose protocol with prospectively ECG-triggered 2nd generation dual-source CT (DSCT), using cardiac MRI (cMRI) as the reference standard.
Twenty patients underwent 1.5T cMRI and prospectively ECG-triggered dual-step pulsing cardiac DSCT. This image acquisition mode performs low-radiation (20% tube current) imaging over the majority of the cardiac cycle and applies full radiation only during a single adjustable phase. Full-radiation-phase images were used to assess cardiac morphology, while low-radiation-phase images were used to measure left and right ventricular function and mass. Quantitative CT measurements based on contiguous multiphase short-axis reconstructions from the axial CT data were compared with short-axis SSFP cardiac cine MRI. Contours were manually traced around the ventricular borders for calculation of left and right ventricular end-diastolic volume, end-systolic volume, stroke volume, ejection fraction and myocardial mass for both modalities. Statistical methods included independent t-tests, the Mann-Whitney U test, Pearson correlation statistics, and Bland-Altman analysis.
All CT measurements of left and right ventricular function and mass correlated well with those from cMRI: for left/right end-diastolic volume r=0.885/0.801, left/right end-systolic volume r=0.947/0.879, left/right stroke volume r=0.620/0.697, left/right ejection fraction r=0.869/0.751, and left/right myocardial mass r=0.959/0.702. Mean radiation dose was 6.2±1.8mSv.
Prospectively ECG-triggered, dual-step pulsing cardiac DSCT accurately quantifies left and right ventricular function and myocardial mass in comparison with cMRI with substantially lower radiation exposure than reported for traditional retrospective ECG-gating.
前瞻性评估基于双步骤、低辐射剂量方案的第二代双源 CT（DSCT）进行左、右心室功能和心肌质量测量的准确性，以心脏 MRI（cMRI）为参考标准。
20 例患者接受了 1.5T cMRI 和前瞻性 ECG 触发的双步骤脉冲式心脏 DSCT 检查。这种图像采集模式在心脏周期的大部分时间内采用低辐射（管电流 20%）成像，仅在单个可调阶段应用全辐射。全辐射阶段图像用于评估心脏形态，而低辐射阶段图像用于测量左、右心室功能和质量。基于轴向 CT 数据的连续多相位短轴重建的定量 CT 测量值与短轴稳态自由进动心脏电影 MRI 进行比较。两种方式的左、右心室舒张末期容积、收缩末期容积、心搏量、射血分数和心肌质量的计算均采用手动勾画心室边界。统计方法包括独立 t 检验、Mann-Whitney U 检验、Pearson 相关统计和 Bland-Altman 分析。
左、右心室功能和质量的所有 CT 测量值均与 cMRI 测量值密切相关：左/右舒张末期容积 r=0.885/0.801，左/右收缩末期容积 r=0.947/0.879，左/右心搏量 r=0.620/0.697，左/右射血分数 r=0.869/0.751，左/右心肌质量 r=0.959/0.702。平均辐射剂量为 6.2±1.8mSv。
与传统回顾性 ECG 门控相比，前瞻性 ECG 触发的双步骤脉冲式心脏 DSCT 能以明显更低的辐射暴露，准确地定量评估左、右心室功能和心肌质量。
