Image Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada.
IEEE Trans Biomed Eng. 2012 May;59(5):1444-53. doi: 10.1109/TBME.2012.2189392. Epub 2012 Feb 28.
Transcatheter aortic valve implantation is a minimally invasive alternative to open-heart surgery for aortic stenosis in which a stent-based bioprosthetic valve is delivered into the heart on a catheter. Limited visualization during this procedure can lead to severe complications. Improved visualization can be provided by live registration of transesophageal echo (TEE) and fluoroscopy images intraoperatively. Since the TEE probe is always visible in the fluoroscopy image, it is possible to track it using fiducial-based single-perspective pose estimation. In this study, inherent probe tracking performance was assessed, and TEE to fluoroscopy registration accuracy and robustness were evaluated. Results demonstrated probe tracking errors of below 0.6 mm and 0.2°, a 2-D RMS registration error of 1.5 mm, and a tracking failure rate of below 1%. In addition to providing live registration and better accuracy and robustness compared to existing TEE probe tracking methods, this system is designed to be suitable for clinical use. It is fully automatic, requires no additional operating room hardware, does not require intraoperative calibration, maintains existing procedure and imaging workflow without modification, and can be implemented in all cardiac centers at extremely low cost.
经导管主动脉瓣植入术是一种微创替代方法，用于治疗主动脉瓣狭窄，该方法通过导管将基于支架的生物假体瓣膜递送到心脏。由于该手术过程中可视化程度有限，可能会导致严重的并发症。术中实时注册经食管超声心动图（TEE）和荧光透视图像可以提供更好的可视化效果。由于 TEE 探头在荧光透视图像中始终可见，因此可以使用基于基准点的单视角位姿估计来跟踪它。在这项研究中，评估了固有探头跟踪性能，并评估了 TEE 与荧光透视的配准精度和鲁棒性。结果表明，探头跟踪误差低于 0.6 毫米和 0.2°，2-D RMS 配准误差为 1.5 毫米，跟踪失败率低于 1%。与现有的 TEE 探头跟踪方法相比，除了提供实时注册以及更高的准确性和鲁棒性之外，该系统还专为临床使用而设计。它是全自动的，不需要额外的手术室硬件，不需要术中校准，在不修改现有程序和成像工作流程的情况下，维持现有的程序和成像工作流程，并且可以以极低的成本在所有心脏中心实施。
