Semi-automatic quantification of 4D left ventricular blood flow.
Semi-automatic quantification of 4D left ventricular blood flow.
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DOI：
10.1186/1532-429x-12-9
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发表时间：
2010-02-12
期刊：
影响因子：
--
通讯作者：
Ebbers T
中科院分区：
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作者：
Eriksson J;Carlhäll CJ;Dyverfeldt P;Engvall J;Bolger AF;Ebbers T
跳动的心脏是通过心血管系统的血液流动的发生器。在心脏自身的腔室内，正常的复杂血液流动模式可能会受到疾病的干扰。缺乏用于量化具有4D（3D+时间）性质的心内血流的方法。我们试图开发和验证一种新的半自动分析方法，整合流量和形态数据。在6名健康受试者和3名扩张型心肌病患者中，采集了三维电影相位对比心血管磁共振（CMR）速度数据和平衡稳态自由进动长轴和短轴图像。在等容收缩（IVC）和等容舒张（IVR）时，从短轴图像中分割LV内膜。在IVC时，从IVC LV血容量发出路径线，并在时间上向前和向后追踪，直到IVR，因此包括整个心动周期。IVR体积用于确定路径线是否离开LV以及离开LV的位置。该信息用于将路径线自动分离为四个不同的流量分量：直接流量、滞留流入量、延迟射血流量和残余量。通过将路径线的数量乘以每条路径线所代表的血容量，计算每个组分的血容量。通过分析左室流入和流出量、四种血流成分和舒张末期容积，评价了该方法的准确性和观察者间和观察者内的重现性。测定所有受试者左室血流成分的体积和分布。计算的LV流出量[ml]（67 ± 13）似乎分别落在通过平面相位对比CMR（77 ± 16）和多普勒超声（58 ± 10）获得的结果之间。计算的左室流入量（68 ± 11）和流出量（67 ± 13）匹配良好（NS）。获得了用于评估流动组分体积的低观察者间和观察者内变异性。这种用于定量4D血流的半自动分析方法可获得准确的LV流入和流出体积，并可高度再现LV血流成分的评估。
The beating heart is the generator of blood flow through the cardiovascular system. Within the heart's own chambers, normal complex blood flow patterns can be disturbed by diseases. Methods for the quantification of intra-cardiac blood flow, with its 4D (3D+time) nature, are lacking. We sought to develop and validate a novel semi-automatic analysis approach that integrates flow and morphological data. In six healthy subjects and three patients with dilated cardiomyopathy, three-directional, three-dimensional cine phase-contrast cardiovascular magnetic resonance (CMR) velocity data and balanced steady-state free-precession long- and short-axis images were acquired. The LV endocardium was segmented from the short-axis images at the times of isovolumetric contraction (IVC) and isovolumetric relaxation (IVR). At the time of IVC, pathlines were emitted from the IVC LV blood volume and traced forwards and backwards in time until IVR, thus including the entire cardiac cycle. The IVR volume was used to determine if and where the pathlines left the LV. This information was used to automatically separate the pathlines into four different components of flow: Direct Flow, Retained Inflow, Delayed Ejection Flow and Residual Volume. Blood volumes were calculated for every component by multiplying the number of pathlines with the blood volume represented by each pathline. The accuracy and inter- and intra-observer reproducibility of the approach were evaluated by analyzing volumes of LV inflow and outflow, the four flow components, and the end-diastolic volume. The volume and distribution of the LV flow components were determined in all subjects. The calculated LV outflow volumes [ml] (67 ± 13) appeared to fall in between those obtained by through-plane phase-contrast CMR (77 ± 16) and Doppler ultrasound (58 ± 10), respectively. Calculated volumes of LV inflow (68 ± 11) and outflow (67 ± 13) were well matched (NS). Low inter- and intra-observer variability for the assessment of the volumes of the flow components was obtained. This semi-automatic analysis approach for the quantification of 4D blood flow resulted in accurate LV inflow and outflow volumes and a high reproducibility for the assessment of LV flow components.