Iowa Institute for Biomedical Imaging, The University of Iowa, Iowa City, IA 52242, USA.
Institute of Clinical and Experimental Medicine (IKEM) in Prague, Czech Republic.
Med Image Anal. 2018 Dec;50:95-105. doi: 10.1016/j.media.2018.09.003. Epub 2018 Sep 14.
Cardiac allograft vasculopathy (CAV) accounts for about 30% of all heart-transplant (HTx) patient deaths. For patients at high risk for CAV complications after HTx, therapy must be initiated early to be effective. Therefore, new phenotyping approaches are needed to identify such HTx patients at the earliest possible time. Coronary optical coherence tomography (OCT) images were acquired from 50 HTx patients 1 and 12 months after HTx. Quantitative analysis of coronary wall morphology used LOGISMOS segmentation strategy to simultaneously identify three wall-layer surfaces for the entire pullback length in 3D: luminal, outer intimal, and outer medial surfaces. To quantify changes of coronary wall morphology between 1 and 12 months after HTx, the two pullbacks were mutually co-registered. Validation of layer thickness measurements showed high accuracy of performed layer analyses with layer thickness measures correlating well with manually-defined independent standard (R = 0.93, y=1.0x-6.2μm), average intimal+medial thickness errors were 4.98 ± 31.24 µm, comparable with inter-observer variability. Quantitative indices of coronary wall morphology 1 month and 12 months after HTx showed significant local as well as regional changes associated with CAV progression. Some of the newly available fully-3D baseline indices (intimal layer brightness, medial layer brightness, medial thickness, and intimal+medial thickness) were associated with CAV-related progression of intimal thickness showing promise of identifying patients subjected to rapid intimal thickening at 12 months after HTx from OCT-image data obtained just 1 month after HTx. Our approach allows quantification of location-specific alterations of coronary wall morphology over time and is sensitive even to very small changes of wall layer thicknesses that occur in patients following heart transplant.
心脏移植后冠状动脉血管病（CAV）约占所有心脏移植（HTx）患者死亡的 30%。对于 HTx 后发生 CAV 并发症风险较高的患者，必须尽早开始治疗才能有效。因此，需要新的表型分析方法来尽早识别此类 HTx 患者。从 50 例 HTx 患者中获得 HTx 后 1 个月和 12 个月的冠状动脉光学相干断层扫描（OCT）图像。使用 LOGISMOS 分割策略对冠状动脉壁形态进行定量分析，同时在 3D 中识别整个回撤长度的三个壁层表面：管腔、外内膜和外中膜表面。为了量化 HTx 后 1 个月至 12 个月期间冠状动脉壁形态的变化，两次回撤相互配准。对层厚测量的验证表明，所进行的层分析具有很高的准确性，层厚测量与手动定义的独立标准相关性良好（R=0.93，y=1.0x-6.2μm），平均内膜+中膜厚度误差为 4.98±31.24μm，与观察者间变异性相当。HTx 后 1 个月和 12 个月时冠状动脉壁形态的定量指标显示出与 CAV 进展相关的显著局部和区域性变化。一些新的全 3D 基线指数（内膜层亮度、中膜层亮度、中膜厚度和内膜+中膜厚度）与 CAV 相关的内膜厚度进展有关，这表明从 HTx 后仅 1 个月获得的 OCT 图像数据中，有可能识别出 12 个月后发生快速内膜增厚的患者。我们的方法允许随时间定量评估冠状动脉壁形态的特定位置变化，甚至对心脏移植后患者发生的壁层厚度非常小的变化也很敏感。
