Department of Mechanical Engineering, Stanford University, Stanford, CA, USA.
Ultrasound Med Biol. 2011 Dec;37(12):2037-54. doi: 10.1016/j.ultrasmedbio.2011.08.007. Epub 2011 Oct 20.
We present a method for real-time, freehand 3D ultrasound (3D-US) reconstruction of moving anatomy, with specific application towards guiding the catheter ablation procedure in the left atrium. Using an intracardiac echo (ICE) catheter with a pose (position/orientation) sensor mounted to its tip, we continually mosaic 2D-ICE images of a left atrium phantom model to form a 3D-US volume. Our mosaicing strategy employs a probabilistic framework based on simultaneous localization and mapping (SLAM), a technique commonly used in mobile robotics for creating maps of unexplored environments. The measured ICE catheter tip pose provides an initial estimate for compounding 2D-ICE image data into the 3D-US volume. However, we simultaneously consider the overlap-consistency shared between 2D-ICE images and the 3D-US volume, computing a "corrected" tip pose if need be to ensure spatially-consistent reconstruction. This allows us to compensate for anatomic movement and sensor drift that would otherwise cause motion artifacts in the 3D-US volume. Our approach incorporates 2D-ICE data immediately after acquisition, allowing us to continuously update the registration parameters linking sensor coordinates to 3D-US coordinates. This, in turn, enables real-time localization and display of sensorized therapeutic catheters within the 3D-US volume for facilitating procedural guidance.
我们提出了一种实时、徒手 3D 超声（3D-US）重建运动解剖结构的方法，特别适用于指导左心房导管消融术。使用带有安装在其尖端的位置/方向传感器的腔内超声（ICE）导管，我们连续拼接左心房模型的 2D-ICE 图像以形成 3D-US 体积。我们的拼接策略采用基于同时定位和映射（SLAM）的概率框架，这是移动机器人中用于创建未知环境地图的常用技术。测量的 ICE 导管尖端位置提供了将 2D-ICE 图像数据复合到 3D-US 体积中的初始估计。但是，我们同时考虑 2D-ICE 图像和 3D-US 体积之间的重叠一致性，如果需要，计算“校正”尖端位置以确保空间一致的重建。这允许我们补偿解剖运动和传感器漂移，否则会导致 3D-US 体积中的运动伪影。我们的方法在采集后立即整合 2D-ICE 数据，从而能够连续更新将传感器坐标链接到 3D-US 坐标的配准参数。这反过来又能够实时定位和显示 3D-US 体积内带有传感器的治疗导管，以方便手术指导。
