Multi-Modality Medical Imaging Group, TechMed Centre, University of Twente, Enschede, The Netherlands; Department of Vascular Surgery, Rijnstate Hospital, Arnhem, The Netherlands; Physics of Fluids Group, TechMed Centre, University of Twente, Enschede, The Netherlands.
Multi-Modality Medical Imaging Group, TechMed Centre, University of Twente, Enschede, The Netherlands; Department of Vascular Surgery, Rijnstate Hospital, Arnhem, The Netherlands; Physics of Fluids Group, TechMed Centre, University of Twente, Enschede, The Netherlands.
Ultrasound Med Biol. 2022 Aug;48(8):1518-1527. doi: 10.1016/j.ultrasmedbio.2022.03.016. Epub 2022 May 13.
Local flow patterns influence stent patency, while blood flow quantification in stents is challenging. The aim of this study was to investigate the feasibility of 2-D blood flow quantification using high-frame-rate, contrast-enhanced ultrasound (HFR-CEUS) and particle image velocimetry (PIV), or echoPIV, in patients with aortoiliac stents. HFR-CEUS measurements were performed at 129 locations in 62 patients. Two-dimensional blood flow velocity fields were obtained using echoPIV. Visual inspection was performed by five observers to evaluate feasibility. The contrast-to-background ratio and average vector correlation were calculated and compared between stented and native vessel segments. Flow quantification with echoPIV was feasible in 128 of 129 locations (99%), with optimal quantification in 40 of 129 locations (31%). Partial quantification was achieved in 88 of 129 locations (68%), where one or multiple limiting issues occurred (not related to the stent) including loss of correlation during systole (57/129), short vessel segments (20/129), loss of contrast during diastole (20/129) and shadow regions (20/129). The contrast-to-background ratio and vector correlation were lower downstream in the imaged blood vessel, independent of the location of the stent. In conclusion, echoPIV was feasible in stents placed in the aortoiliac region, and the stents did not adversely affect flow tracking.
局部血流模式会影响支架通畅性，而支架内血流定量评估具有挑战性。本研究旨在探讨使用高帧率对比增强超声（HFR-CEUS）和粒子图像测速（PIV）或回声 PIV（echoPIV）在腹主动脉瘤支架置入患者中进行二维血流定量的可行性。在 62 名患者的 129 个部位进行 HFR-CEUS 测量。使用 echoPIV 获得二维血流速度场。由 5 名观察者进行视觉检查以评估可行性。计算并比较支架内和原生血管段的对比背景比和平均矢量相关性。在 129 个部位中的 128 个部位（99%）可以进行回声 PIV 血流定量，在 129 个部位中的 40 个部位（31%）可以进行最佳定量。在 129 个部位中的 88 个部位（68%）实现了部分定量，其中存在一个或多个限制因素（与支架无关），包括收缩期相关性丢失（57/129）、血管段较短（20/129）、舒张期对比丢失（20/129）和阴影区域（20/129）。在成像血管的下游，无论支架的位置如何，对比背景比和矢量相关性均降低。结论：在腹主动脉瘤支架置入部位，echoPIV 是可行的，支架不会对血流跟踪产生不利影响。
