Schrauwen Jelle T C, Karanasos Antonios, van Ditzhuijzen Nienke S, Aben Jean-Paul, van der Steen Antonius F W, Wentzel Jolanda J, Gijsen Frank J H
Department of Biomedical Engineering, Thoraxcenter, Erasmus Medical Center, Rotterdam, the Netherlands.
Department of Cardiology, Thoraxcenter, Erasmus Medical Center, Rotterdam, the Netherlands.
PLoS One. 2015 Dec 21;10(12):e0145114. doi: 10.1371/journal.pone.0145114. eCollection 2015.
Wall shear stress (WSS) plays a key role in the onset and progression of atherosclerosis in human coronary arteries. Especially sites with low and oscillating WSS near bifurcations have a higher propensity to develop atherosclerosis. WSS computations in coronary bifurcations can be performed in angiography-based 3D reconstructions. It is essential to evaluate how reconstruction errors influence WSS computations in mildly-diseased coronary bifurcations. In mildly-diseased lesions WSS could potentially provide more insight in plaque progression.
Four Plexiglas phantom models of coronary bifurcations were imaged with bi-plane angiography. The lumens were segmented by two clinically experienced readers. Based on the segmentations 3D models were generated. This resulted in three models per phantom: one gold-standard from the phantom model itself, and one from each reader. Steady-state and transient simulations were performed with computational fluid dynamics to compute the WSS. A similarity index and a noninferiority test were used to compare the WSS in the phantoms and their reconstructions. The margin for this test was based on the resolution constraints of angiography.
The reconstruction errors were similar to previously reported data; in seven out of eight reconstructions less than 0.10 mm. WSS in the regions proximal and far distal of the stenosis showed a good agreement. However, the low WSS areas directly distal of the stenosis showed some disagreement between the phantoms and the readers. This was due to small deviations in the reconstruction of the stenosis that caused differences in the resulting jet, and consequently the size and location of the low WSS area.
This study showed that WSS can accurately be computed within angiography-based 3D reconstructions of coronary arteries with early stage atherosclerosis. Qualitatively, there was a good agreement between the phantoms and the readers. Quantitatively, the low WSS regions directly distal to the stenosis were sensitive to small reconstruction errors.
壁面剪应力（WSS）在人类冠状动脉粥样硬化的发生和发展中起关键作用。特别是在分叉附近具有低且振荡的WSS的部位，发生动脉粥样硬化的倾向更高。冠状动脉分叉处的WSS计算可在基于血管造影的三维重建中进行。评估重建误差如何影响轻度病变冠状动脉分叉处的WSS计算至关重要。在轻度病变中，WSS可能为斑块进展提供更多见解。
使用双平面血管造影对四个冠状动脉分叉的有机玻璃模型进行成像。由两位临床经验丰富的阅片者对管腔进行分割。基于分割结果生成三维模型。每个模型产生三个模型：一个来自模型本身的金标准模型，以及每个阅片者生成的一个模型。使用计算流体动力学进行稳态和瞬态模拟以计算WSS。使用相似性指数和非劣效性检验来比较模型及其重建中的WSS。该检验的界值基于血管造影的分辨率限制。
重建误差与先前报道的数据相似；在八个重建中，有七个小于0.10毫米。狭窄近端和远端区域的WSS显示出良好的一致性。然而，狭窄远端直接的低WSS区域在模型和阅片者之间存在一些差异。这是由于狭窄重建中的小偏差导致了射流的差异，进而导致低WSS区域的大小和位置不同。
本研究表明，在基于血管造影的早期动脉粥样硬化冠状动脉三维重建中，可以准确计算WSS。定性地说，模型和阅片者之间有良好的一致性。定量地说，狭窄远端直接的低WSS区域对小的重建误差敏感。
