IEEE Trans Med Imaging. 2018 Jan;37(1):47-60. doi: 10.1109/TMI.2017.2723545. Epub 2017 Jul 4.
In X-ray fluoroscopy, static overlays are used to visualize soft tissue. We propose a system for cardiac and respiratory motion compensation of these overlays. It consists of a 3-D motion model created from real-time magnetic resonance (MR) imaging. Multiple sagittal slices are acquired and retrospectively stacked to consistent 3-D volumes. Slice stacking considers cardiac information derived from the ECG and respiratory information extracted from the images. Additionally, temporal smoothness of the stacking is enhanced. Motion is estimated from the MR volumes using deformable 3-D/3-D registration. The motion model itself is a linear direct correspondence model using the same surrogate signals as slice stacking. In X-ray fluoroscopy, only the surrogate signals need to be extracted to apply the motion model and animate the overlay in real time. For evaluation, points are manually annotated in oblique MR slices and in contrast-enhanced X-ray images. The 2-D Euclidean distance of these points is reduced from 3.85 to 2.75 mm in MR and from 3.0 to 1.8 mm in X-ray compared with the static baseline. Furthermore, the motion-compensated overlays are shown qualitatively as images and videos.
在 X 射线透视中，静态叠加用于可视化软组织。我们提出了一种用于这些叠加的心脏和呼吸运动补偿的系统。它由从实时磁共振（MR）成像创建的 3D 运动模型组成。获取多个矢状切片，并回顾性地将其堆叠到一致的 3D 体积中。切片堆叠考虑了从 ECG 中得出的心脏信息和从图像中提取的呼吸信息。此外，还增强了堆叠的时间平滑度。使用可变形的 3D/3D 配准从 MR 体积中估计运动。运动模型本身是一种线性直接对应模型，使用与切片堆叠相同的替代信号。在 X 射线透视中，仅需提取替代信号即可应用运动模型并实时动画叠加。为了进行评估，手动在斜 MR 切片和对比增强 X 射线图像中标注点。与静态基线相比，这些点的 2D 欧几里得距离在 MR 中从 3.85 减少到 2.75mm，在 X 射线中从 3.0 减少到 1.8mm。此外，运动补偿的叠加以图像和视频的形式定性显示。
