Gill Gauravpal S, Weissman Gaby, Meirovich Yael F, Medvedofsky Diego, Mohammed Selma F, Waksman Ron, Garcia-Garcia Hector M
MedStar Washington Hospital Center, Washington, D.C., United States of America.
MedStar Cardiovascular Research Network, Washington, D.C., United States of America.
Cardiovasc Revasc Med. 2019 May;20(5):381-386. doi: 10.1016/j.carrev.2019.01.024. Epub 2019 Jan 23.
Multi-detector gated cardiac computed tomography (CCT) allows three-dimensional (3D) quantification of cardiac chambers and is clinically indicated to assess left ventricular assist device (LVAD) malfunction and complications. Automated volumetric analysis is, however, disrupted by inflow cannula artifact in patients with LVAD. With this study, we evaluated intra-observer variability in semi-automated 3D cardiac volumetric analysis using CCT in patients with LVADs.
Ten clinically indicated CCTs were studied retrospectively from 9 patients with LVADs. 3D chamber quantification included left and right ventricles end-systolic and end-diastolic volumes (ESV, EDV); and left and right atrial ESV. Derived measurements included cardiac output (CO), ejection fraction (EF), and stroke volume (SV). Automated volumetric analysis was performed, and manual corrections were added when necessary. Absolute and relative differences, Bland-Altman plots, and interclass correlation coefficients (ICCs) were used to assess intra-observer reproducibility for these measurements.
Intra-observer reproducibility was excellent for volumetric (ICC >0.99) and derived data (ICC >0.91). Comparing right vs left heart volumetric assessments, the former had a higher relative difference (atria 2.8% vs 1.6%, ESV 3.0% vs 1.9%, EDV 2.7% vs 1.3%), which also translated to a greater relative difference in right-side derived data (CO 11.1% vs. 8.8%, EF 10.5% vs. 9.9%, SV 10.9% vs. 9.0%). The mean difference in left ventricular ejection fraction was 0.4% (limits of agreement [LOA]: -2 and 3.2) and right ventricular ejection fraction was 1.2% (LOA: -4.7 and 7.1).
Our results for semi-automated 3D volumetric analysis showed excellent reproducibility for both volumetric and derived data.
Electrocardiography-gated cardiac computed tomography with semi-automated volumetric analysis has excellent reproducibility in patients with left ventricular assist device making it imaging modality of choice for functional assessment in this patient population, where cardiac magnetic resonance imaging is contraindicated and transthoracic echocardiography may be limited by poor acoustic windows.
多探测器门控心脏计算机断层扫描（CCT）可对心腔进行三维（3D）定量分析，临床上用于评估左心室辅助装置（LVAD）的故障和并发症。然而，LVAD患者的流入插管伪影会干扰自动容积分析。在本研究中，我们评估了使用CCT对LVAD患者进行半自动3D心脏容积分析时观察者内的变异性。
回顾性研究了9例LVAD患者的10次临床指征性CCT。3D心腔定量分析包括左、右心室的收缩末期和舒张末期容积（ESV、EDV）；以及左、右心房的ESV。派生测量包括心输出量（CO）、射血分数（EF）和每搏输出量（SV）。进行自动容积分析，并在必要时进行手动校正。使用绝对和相对差异、Bland-Altman图和组内相关系数（ICC）来评估这些测量的观察者内再现性。
观察者内再现性在容积数据（ICC>0.99）和派生数据（ICC>0.91）方面表现出色。比较右心和左心的容积评估，前者的相对差异更高（心房分别为2.8%对1.6%，ESV为3.0%对1.9%，EDV为2.7%对1.3%），这也导致右侧派生数据的相对差异更大（CO分别为11.1%对8.8%，EF为10.5%对9.9%，SV为10.9%对9.0%）。左心室射血分数的平均差异为0.4%（一致性界限[LOA]：-2和3.2），右心室射血分数的平均差异为1.2%（LOA：-4.7和7.1）。
我们的半自动3D容积分析结果显示，容积数据和派生数据均具有出色的再现性。
心电图门控心脏计算机断层扫描结合半自动容积分析在左心室辅助装置患者中具有出色的再现性，使其成为该患者群体功能评估的首选成像方式，因为心脏磁共振成像存在禁忌，而经胸超声心动图可能因声学窗口不佳而受到限制。
