A simple, realistic walled phantom for intravascular and intracardiac applications.
A simple, realistic walled phantom for intravascular and intracardiac applications.
复制标题
一个简单、逼真的有壁模型，适用于血管内和心脏内应用。
DOI：
10.1007/s11548-020-02201-3
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发表时间：
2020
影响因子：
3
通讯作者：
Nisar H
中科院分区：
文献类型：
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作者：
Nisar H
目的研制一种简单、解剖和触觉逼真、可与血管内和心内超声兼容的血管假体。这种低成本的双层假体通过超声成像显示血管壁和周围组织，弥补了传统的无壁假体和无壁假体之间的差距。该模型可以更好地辅助临床工具培训、血管内设备测试、血流研究以及血管内和心内手术系统算法验证。方法采用含分散剂的聚乙烯醇低温凝胶（PVA-c）制备血管和组织模拟材料。我们的具体设计针对下腔静脉和肾分叉，并使用CAD软件建模。定制的模具和容器3d打印成型所需的容器壁。通过改变散射剂的浓度以及在制造过程中所经历的冻融循环次数，制备了三种幻膜。使用Foresight™ICE探头对每个假体进行超声成像评估。几何验证是通过比较CAD设计和CT扫描的幻影。结果在模拟血管层和模拟组织层中分别使用浓度为2.5%和0.05%的散射剂构建出理想的血管模型。对三个幻像的成像显示，增加冻融循环次数并没有显著增强图像对比度。将超声图像与CT图像进行对比，得出腔直径的平均误差为0.9。结论心内超声成像时，假体具有解剖真实感，为超声探头和导管的运动提供了光滑的腔体。血管幻像能够验证血管内和心脏内的图像引导系统。简单的施工技术也为设计复杂的多层动脉模型提供了一个工作流程。
PurposeThis work aims to develop a simple, anatomically and haptically realistic vascular phantom, compatible with intravascular and intracardiac ultrasound. The low-cost, dual-layered phantom bridges the gap between traditional wall-only and wall-less phantoms by showing both the vessel wall and surrounding tissue in ultrasound imaging. This phantom can better assist clinical tool training, testing of intravascular devices, blood flow studies, and validation of algorithms for intravascular and intracardiac surgical systems.MethodsPolyvinyl alcohol cryogel (PVA-c) incorporating a scattering agent was used to obtain vessel and tissue-mimicking materials. Our specific design targeted the inferior vena cava and renal bifurcations which were modelled using CAD software. A custom mould and container were 3D-printed for shaping the desired vessel wall. Three phantoms were prepared by varying both the concentrations of scattering agent as well as the number of freeze–thaw cycles to which the phantom layers were subjected during the manufacturing process. Each phantom was evaluated using ultrasound imaging using the Foresight™ ICE probe. Geometrical validation was provided by comparing CAD design to a CT scan of the phantom.ResultsThe desired vascular phantom was constructed using 2.5% and 0.05% scattering agent concentration in the vessel and tissue-mimicking layers, respectively. Imaging of the three phantoms showed that increasing the number of freeze–thaw cycles did not significantly enhance the image contrast. Comparison of the US images with their CT equivalents resulted in an average error of 0.9for the lumen diameter.ConclusionThe phantom is anatomically realistic when imaged with intracardiac ultrasound and provides a smooth lumen for the ultrasound probe and catheter to manoeuvre. The vascular phantom enables validation of intravascular and intracardiac image guidance systems. The simple construction technique also provides a workflow for designing complex, multi-layered arterial phantoms.