Reducing Line-of-Block Artifacts in Cardiac Activation Maps Estimated Using ECG Imaging: A Comparison of Source Models and Estimation Methods
Reducing Line-of-Block Artifacts in Cardiac Activation Maps Estimated Using ECG Imaging: A Comparison of Source Models and Estimation Methods
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DOI：
10.1109/tbme.2021.3135154
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发表时间：
2022-06-01
影响因子：
4.6
通讯作者：
Dossel, Olaf
中科院分区：
文献类型：
--
作者：
Schuler, Steffen;Schaufelberger, Matthias;Dossel, Olaf
目的：研究使用心电图成像估计的心脏激动图，并找到减少块线（LoB）伪影的方法，同时保留真实的LoB。方法：对137个模拟心室兴奋进行体表电位计算。随后，求解逆问题以获得细胞外电位（EP）和跨膜电压（TMV）。由此，使用四种方法估计激活时间（AT），并与地面实况进行比较。使用两种心脏网格分辨率对该过程进行了评价。通过分析空间和时间平滑对源信号形态的影响，确定了导致LoB伪影的因素。结果：使用时空导数的AT估计性能优于使用时间导数。与基于偏转的AT估计相比，基于相关性的方法不太容易出现LoB伪影，但在识别真实的LoB方面表现较差。时间平滑可以消除TMV的伪影，但不能消除EP的伪影，这可能与它们的时间形态有关。与EP相比，TMV导致隔膜上的AT更准确。网格分辨率对逆向重建有不可忽视的影响，但小距离对于基于互相关的AT延迟估计很重要。结论：LoB伪影主要是由逆重建固有的空间平滑效应引起的。在评估的配置中，只有基于偏转的AT估计结合TMV和强时间平滑可以防止LoB伪影，同时保留真实的LoB。重要性：慢传导区域具有相当大的临床意义，在非侵入性房性心动过速中观察到的LoB伪影可能导致误解。我们通过识别导致这种伪影的因素来解决这个问题。
Objective: To investigatecardiac activation maps estimated using electrocardiographic imaging and to find methods reducing line-of-block (LoB) artifacts, while preserving real LoBs. Methods: Body surface potentials were computed for 137 simulated ventricular excitations. Subsequently, the inverse problem was solved to obtain extracellular potentials (EP) and transmembrane voltages (TMV). From these, activation times (AT) were estimated using four methods and compared to the ground truth. This process was evaluated with two cardiac mesh resolutions. Factors contributing to LoB artifacts were identified by analyzing the impact of spatial and temporal smoothing on the morphology of source signals. Results: AT estimation using a spatiotemporal derivative performed better than using a temporal derivative. Compared to deflection-based AT estimation, correlation-based methods were less prone to LoB artifacts but performed worse in identifying real LoBs. Temporal smoothing could eliminate artifacts for TMVs but not for EPs, which could be linked to their temporal morphology. TMVs led to more accurate ATs on the septum than EPs. Mesh resolution had anegligible effect on inverse reconstructions, but small distances were important for cross-correlation-based estimation of AT delays. Conclusion: LoB artifacts are mainly caused by the inherent spatial smoothing effect of the inverse reconstruction. Among the configurations evaluated, only deflection-based AT estimation in combination with TMVs and strong temporal smoothing can prevent LoB artifacts, while preserving real LoBs. Significance: Regions of slow conduction are of considerable clinical interest and LoB artifacts observed in non-invasive ATs can lead to misinterpretations. We addressed this problem by identifying factors causing such artifacts.