Robarts Research Institute, 1151 Richmond St., London, ON, N6A5B7, Canada.
School of Biomedical Engineering, Western University, 1151 Richmond St, London, ON, N6A3K7, Canada.
Int J Comput Assist Radiol Surg. 2022 Sep;17(9):1569-1577. doi: 10.1007/s11548-022-02660-w. Epub 2022 May 19.
Tricuspid valve (TV) interventions face the challenge of imaging the anatomy and tools because of the 'TEE-unfriendly' nature of the TV. In edge-to-edge TV repair, a core step is to position the clip perpendicular to the coaptation gap. In this study, we provide a semi-automated method to localize the VC from Doppler intracardiac echo (ICE) imaging in a tracked 3D space, thus providing a pre-mapped location of the coaptation gap to assist device positioning.
A magnetically tracked ICE probe with Doppler imaging capabilities is employed in this study for imaging three patient-specific TVs placed in a pulsatile heart phantom. For each of the valves, the ICE probe is positioned to image the maximum regurgitant flow for five cardiac cycles. An algorithm then extracts the regurgitation imaging and computes the exact location of the vena contracta on the image.
Across the three pathological, patient-specific valves, the average distance error between the detected VC and the ground truth model is [Formula: see text]mm. For each of the valves, one case represented the outlier where the algorithm misidentified the vena contracta to be near the annulus. In such cases, it is recommended to retake the five-second imaging data.
This study presented a method for ultrasound-based localization of vena contracta in 3D space. Mapping such anatomical landmarks has the potential to assist with device positioning and to simplify tricuspid valve interventions by providing more contextual information to the interventionalists, thus enhancing their spatial awareness. Additionally, ICE can be used to provide live US and Doppler imaging of the complex TV anatomy throughout the procedure.
由于三尖瓣（TV）的“经食管超声心动图（TEE）不友好”特性，TV 介入面临着成像解剖结构和工具的挑战。在瓣环对瓣环修复中，核心步骤是将夹子垂直于贴合间隙定位。在这项研究中，我们提供了一种半自动方法，从跟踪的 3D 空间中的多普勒心内超声（ICE）成像中定位 VC，从而提供贴合间隙的预映射位置以辅助器械定位。
本研究使用具有多普勒成像功能的磁跟踪 ICE 探头对放置在脉动心脏模型中的三个特定于患者的 TV 进行成像。对于每个瓣膜，将 ICE 探头定位以在五个心动周期内对最大反流流量进行成像。然后，算法提取反流成像并计算图像上的精确收缩期最小直径位置。
在三个病理、特定于患者的瓣膜中，检测到的 VC 和真实模型之间的平均距离误差为 [Formula: see text]mm。对于每个瓣膜，有一种情况是算法错误地将收缩期最小直径识别为靠近瓣环，这种情况被视为异常。在这种情况下，建议重新获取五秒的成像数据。
本研究提出了一种基于超声的 3D 空间 VC 定位方法。对这些解剖学标志进行映射有可能通过向介入医生提供更多上下文信息来辅助器械定位，并简化三尖瓣介入，从而增强他们的空间意识。此外，ICE 可用于在整个手术过程中提供实时 US 和复杂 TV 解剖结构的多普勒成像。
