Reiner Caecilia S, Williamson Tom, Winklehner Thomas, Lisse Sean, Fink Daniel, DeLancey John O L, Betschart Cornelia
Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, Zurich, Switzerland; University of Zurich, Zurich, Switzerland.
ARTORG, University of Berne, Berne, Switzerland.
Comput Med Imaging Graph. 2017 Jul;59:28-37. doi: 10.1016/j.compmedimag.2017.05.005. Epub 2017 Jun 3.
In pelvic organ prolapse (POP), the organs are pushed downward along the lines of gravity, so measurements along this longitudinal body axis are desirable. We propose a universally applicable 3D coordinate system that corrects for changes in pelvic inclination and that allows the localization of any point in the pelvis at rest or under dynamic conditions on magnetic resonance images (MRI) of pelvic floor disorders in a scanner- and software independent manner. The proposed 3D coordinate system called 3D Pelvic Inclination Correction System (PICS) is constructed utilizing four bony landmark points, with the origin set at the inferior pubic point, and three additional points at the sacrum (sacrococcygeal joint) and both ischial spines, which are clearly visible on MRI images. The feasibility and applicability of the moving frame was evaluated using MRI datasets from five women with pelvic organ prolapse, three undergoing static MRI and two undergoing dynamic MRI of the pelvic floor in a supine position. The construction of the coordinate system was performed utilizing the selected landmarks, with an initial implementation completed in MATLAB. In all cases the selected landmarks were clearly visible, with the construction of the 3D PICS and measurement of pelvic organ positions performed without difficulty. The resulting distance from the organ position to the horizontal PICS plane was compared to a traditional measure based on standard measurements in 2D slices. The two approaches demonstrated good agreement in each of the cases. The developed approach makes quantitative assessment of pelvic organ position in a physiologically relevant 3D coordinate system possible independent of pelvic movement relative to the scanner. It allows the accurate study of the physiologic range of organ location along the body axis ("up or down") as well as defects of the pelvic sidewall or birth-related pelvic floor injuries outside the midsagittal plane, not possible before in a 2D reference line system. Measures in 3D can be monitored over time and may reveal pathology before bothersome symptoms appear, as well as allowing comparison of outcomes between different patient pools after different surgical approaches.
在盆腔器官脱垂（POP）中，器官会沿着重力线向下推移，因此沿身体纵轴进行测量是很有必要的。我们提出了一种通用的三维坐标系，该坐标系可校正骨盆倾斜度的变化，并能以独立于扫描仪和软件的方式，在盆腔底疾病的磁共振成像（MRI）上确定骨盆在静止或动态条件下任何点的位置。所提出的三维坐标系称为三维骨盆倾斜校正系统（PICS），它是利用四个骨性标志点构建的，原点设定在耻骨下点，另外三个点位于骶骨（骶尾关节）和双侧坐骨棘，这些在MRI图像上清晰可见。使用来自五名盆腔器官脱垂女性的MRI数据集评估了移动框架的可行性和适用性，其中三名女性进行了静态MRI检查，两名女性在仰卧位进行了盆底动态MRI检查。利用选定的标志点构建坐标系，最初在MATLAB中完成实现。在所有病例中，选定的标志点都清晰可见，三维PICS的构建和盆腔器官位置的测量都没有困难。将器官位置到水平PICS平面的所得距离与基于二维切片标准测量的传统方法进行比较。在每个病例中，这两种方法都显示出良好的一致性。所开发的方法使得在生理相关的三维坐标系中对盆腔器官位置进行定量评估成为可能，而与骨盆相对于扫描仪的运动无关。它允许准确研究器官沿身体轴（“向上或向下”）的生理位置范围，以及盆腔侧壁的缺陷或矢状面外与分娩相关的盆底损伤，这在以前的二维参考线系统中是不可能的。三维测量可以随时间进行监测，可能在出现令人烦恼的症状之前揭示病变，还能在不同手术方法后比较不同患者群体的结果。
