National Heart Research Institute Singapore, National Heart Centre Singapore, 5 Hospital Drive, Singapore 169609.
Department of Biomedical Engineering and Duke-NUS Medical School, National University Singapore, Singapore.
Eur Heart J Cardiovasc Imaging. 2017 May 1;18(8):880-887. doi: 10.1093/ehjci/jew153.
To optimize conventional coronary optical coherence tomography (OCT) images using the attenuation-compensated technique to improve identification of plaques and the external elastic lamina (EEL) contour.
The attenuation-compensated technique was optimized via manipulating contrast exponent C, and compression exponent N, to achieve an optimal contrast and signal-to-noise ratio (SNR). This was applied to 60 human coronary lesions (38 native and 22 stented) ex vivo conventional coronary OCT images acquired from heart autopsies of 10 patients and matching histology was available as reference. Three independent reviewers assessed the conventional and attenuation-compensated OCT images blindly for plaque characteristics and EEL detection. Conventional OCT and compensated OCT assessment were compared against histology. Using an optimized algorithm, the attenuation-compensated OCT images had a 2-fold improvement in contrast between different tissues in both stented and non-stented epicardial coronaries (P < 0.05). Overall sensitivity and specificity for plaque classification increased from 84 to 89% and from 92 to 94%, respectively, with substantial agreement among the three reviewers (Fleiss' Kappa k, 0.72 and 0.71, respectively). Furthermore, operators were 2.5 times more likely to identify the EEL contour in the attenuation-compensated OCT images (k = 0.72) than in the conventional OCT images (k = 0.36).
The attenuation-compensated technique can be retrospectively applied to conventional OCT images and improves the detection of plaque characteristics and the EEL contour. This approach could complement conventional OCT imaging in the evaluation of plaque characteristics and quantify plaque burden in the clinical setting.
使用衰减补偿技术优化常规冠状动脉光学相干断层扫描（OCT）图像，以提高斑块和外弹力膜（EEL）轮廓的识别能力。
通过操纵对比指数 C 和压缩指数 N 来优化衰减补偿技术，以达到最佳的对比度和信噪比（SNR）。将该技术应用于 60 例人体冠状动脉病变（38 例为天然病变，22 例为支架内病变）的离体常规冠状动脉 OCT 图像，这些图像来自 10 例心脏尸检患者，且均有匹配的组织学作为参考。3 名独立的审查员对常规和衰减补偿 OCT 图像进行盲法评估，以评估斑块特征和 EEL 检测。将常规 OCT 和补偿 OCT 的评估与组织学进行比较。使用优化的算法，补偿 OCT 图像在支架内和非支架内心外膜冠状动脉中不同组织之间的对比度提高了 2 倍（P < 0.05）。斑块分类的整体敏感性和特异性分别从 84%和 92%提高到 89%和 94%，3 名审查员之间具有高度一致性（Fleiss' Kappa k 分别为 0.72 和 0.71）。此外，与常规 OCT 图像（k = 0.36）相比，操作者在衰减补偿 OCT 图像中识别 EEL 轮廓的可能性高 2.5 倍（k = 0.72）。
衰减补偿技术可以回顾性地应用于常规 OCT 图像，并提高斑块特征和 EEL 轮廓的检测能力。这种方法可以补充常规 OCT 成像在评估斑块特征和量化斑块负荷方面的作用，尤其在临床环境中。
