SINTEF Digital, Department of Health Research, Trondheim, Norway.
Norwegian National Center for Minimally Invasive and Image-Guided Diagnostics and Therapy, St. Olavs Hospital, Trondheim, Norway.
Eur Radiol Exp. 2024 Aug 28;8(1):99. doi: 10.1186/s41747-024-00499-1.
Electromagnetic tracking of endovascular instruments has the potential to substantially decrease radiation exposure of patients and personnel. In this study, we evaluated the in vivo accuracy of a vessel-based method to register preoperative computed tomography angiography (CTA) images to physical coordinates using an electromagnetically tracked guidewire. Centerlines of the aortoiliac arteries were extracted from preoperative CTA acquired from five swine. Intravascular positions were obtained from an electromagnetically tracked guidewire. An iterative-closest-point algorithm registered the position data to the preoperative image centerlines. To evaluate the registration accuracy, a guidewire was placed inside the superior mesenteric, left and right renal arteries under fluoroscopic guidance. Position data was acquired with electromagnetic tracking as the guidewire was pulled into the aorta. The resulting measured positions were compared to the corresponding ostia manually identified in the CTA images after applying the registration. The three-dimensional (3D) Euclidean distances were calculated between each corresponding ostial point, and the root mean square (RMS) was calculated for each registration. The median 3D RMS for all registrations was 4.82 mm, with an interquartile range of 3.53-6.14 mm. A vessel-based registration of CTA images to vascular anatomy is possible with acceptable accuracy and encourages further clinical testing. RELEVANCE STATEMENT: This study shows that the centerline algorithm can be used to register preoperative CTA images to vascular anatomy, with the potential to further reduce ionizing radiation exposure during vascular procedures. KEY POINTS: Preoperative images can be used to guide the procedure without ionizing intraoperative imaging. Preoperative imaging can be the only imaging modality used for guidance of vascular procedures. No need to use external fiducial markers to register/match images and spatial anatomy. Acceptable accuracy can be achieved for navigation in a preclinical setting.
电磁跟踪血管内器械有可能大大降低患者和医务人员的辐射暴露。在这项研究中，我们评估了一种基于血管的方法的体内准确性，该方法使用电磁跟踪导丝将术前计算机断层血管造影 (CTA) 图像与物理坐标进行配准。从五只猪获得的术前 CTA 中提取腹主动脉髂动脉的中心线。从电磁跟踪导丝获得血管内位置。迭代最近点算法将位置数据与术前图像中心线进行配准。为了评估注册准确性，在透视引导下将导丝放置在肠系膜上动脉、左肾和右肾动脉内。随着导丝被拉入主动脉，使用电磁跟踪获取位置数据。在应用配准后，手动确定 CTA 图像中相应的口，将测量的位置与相应的口进行比较。计算每个相应口之间的三维 (3D) 欧几里得距离，并为每个注册计算均方根 (RMS)。所有注册的中位数 3D RMS 为 4.82mm，四分位距为 3.53-6.14mm。使用血管配准将 CTA 图像与血管解剖结构进行配准是可行的，并且具有可接受的准确性，这鼓励了进一步的临床测试。相关性陈述：本研究表明，中心线算法可用于将术前 CTA 图像与血管解剖结构进行配准，有可能进一步降低血管手术过程中的电离辐射暴露。要点：术前图像可用于指导手术，而无需进行电离术中成像。术前成像可以是用于指导血管手术的唯一成像方式。无需使用外部基准标记来注册/匹配图像和空间解剖结构。在临床前环境中可以实现可接受的导航精度。
