Zahnd Guillaume, Schrauwen Jelle, Karanasos Antonios, Regar Evelyn, Niessen Wiro, van Walsum Theo, Gijsen Frank
Biomedical Imaging Group Rotterdam, Department of Radiology & Nuclear Medicine and Department of Medical Informatics, Erasmus MC, Rotterdam, The Netherlands.
Department of Biomedical Engineering, Thorax Center, Erasmus MC, Rotterdam, The Netherlands.
Int J Comput Assist Radiol Surg. 2016 Oct;11(10):1779-90. doi: 10.1007/s11548-016-1422-3. Epub 2016 May 28.
Identification of rupture-prone plaques in coronary arteries is a major clinical challenge. Fibrous cap thickness and wall shear stress are two relevant image-based risk factors, but these two parameters are generally computed and analyzed separately. Accordingly, combining these two parameters can potentially improve the identification of at-risk regions. Therefore, the purpose of this study is to investigate the feasibility of the fusion of wall shear stress and fibrous cap thickness of coronary arteries in patient data.
Fourteen patients were included in this pilot study. Imaging of the coronary arteries was performed with optical coherence tomography and with angiography. Fibrous cap thickness was automatically quantified from optical coherence tomography pullbacks using a contour segmentation approach based on fast marching. Wall shear stress was computed by applying computational fluid dynamics on the 3D volume reconstructed from two angiograms. The two parameters then were co-registered using anatomical landmarks such as side branches.
The two image modalities were successfully co-registered, with a mean (±SD) error corresponding to [Formula: see text] of the length of the analyzed region. For all the analyzed participants, the average thinnest portion of each fibrous cap was [Formula: see text], and the average WSS value at the location of the fibrous cap was [Formula: see text]. A unique index was finally generated for each patient via the fusion of fibrous cap thickness and wall shear stress measurements, to translate all the measured parameters into a single risk map.
The introduced risk map integrates two complementary parameters and has potential to provide valuable information about plaque vulnerability.
识别冠状动脉中易破裂斑块是一项重大临床挑战。纤维帽厚度和壁面切应力是两个基于图像的相关风险因素,但这两个参数通常是分别计算和分析的。因此,结合这两个参数可能会改善对危险区域的识别。所以,本研究的目的是探讨在患者数据中融合冠状动脉壁面切应力和纤维帽厚度的可行性。
本初步研究纳入了14名患者。使用光学相干断层扫描和血管造影对冠状动脉进行成像。基于快速行进的轮廓分割方法,从光学相干断层扫描回撤中自动量化纤维帽厚度。通过对从两幅血管造影重建的三维体积应用计算流体动力学来计算壁面切应力。然后使用侧支等解剖标志将这两个参数进行配准。
两种图像模态成功配准,平均(±标准差)误差相当于分析区域长度的[公式:见原文]。对于所有分析的参与者,每个纤维帽的平均最薄部分为[公式:见原文],纤维帽位置处的平均壁面切应力值为[公式:见原文]。最终通过融合纤维帽厚度和壁面切应力测量值为每位患者生成一个独特的指标,将所有测量参数转化为单一风险图。
引入的风险图整合了两个互补参数,有潜力提供有关斑块易损性的有价值信息。