Xie Weiguo, Franke Jochen, Chen Cheng, Grützner Paul A, Schumann Steffen, Nolte Lutz-P, Zheng Guoyan
Institute for Surgical Technology and Biomechanics, University of Bern, Stauffacherstrasse 78, CH-3014, Bern, Switzerland.
Graduate School for Cellular and Biomedical Sciences, University of Bern, Switzerland.
Int J Med Robot. 2015 Jun;11(2):166-80. doi: 10.1002/rcs.1619. Epub 2014 Sep 26.
Complete-pelvis segmentation in antero-posterior pelvic radiographs is required to create a patient-specific three-dimensional pelvis model for surgical planning and postoperative assessment in image-free navigation of total hip arthroplasty.
A fast and robust framework for accurately segmenting the complete pelvis is presented, consisting of two consecutive modules. In the first module, a three-stage method was developed to delineate the left hemi-pelvis based on statistical appearance and shape models. To handle complex pelvic structures, anatomy-specific information processing techniques were employed. As the input to the second module, the delineated left hemi-pelvis was then reflected about an estimated symmetry line of the radiograph to initialize the right hemi-pelvis segmentation. The right hemi-pelvis was segmented by the same three-stage method,
Two experiments conducted on respectively 143 and 40 AP radiographs demonstrated a mean segmentation accuracy of 1.61±0.68 mm. A clinical study to investigate the postoperative assessment of acetabular cup orientations based on the proposed framework revealed an average accuracy of 1.2°±0.9° and 1.6°±1.4° for anteversion and inclination, respectively. Delineation of each radiograph costs less than one minute.
Despite further validation needed, the preliminary results implied the underlying clinical applicability of the proposed framework for image-free THA.
在全髋关节置换术的无图像导航中，为手术规划和术后评估创建患者特异性三维骨盆模型需要对前后位骨盆X线片进行全骨盆分割。
提出了一个用于准确分割完整骨盆的快速且稳健的框架，该框架由两个连续的模块组成。在第一个模块中，开发了一种三阶段方法，基于统计外观和形状模型来描绘左半骨盆。为处理复杂的骨盆结构，采用了解剖学特定的信息处理技术。作为第二个模块的输入，然后将描绘出的左半骨盆围绕X线片的估计对称线进行反射，以初始化右半骨盆分割。右半骨盆通过相同的三阶段方法进行分割。
分别在143张和40张前后位X线片上进行的两项实验表明，平均分割精度为1.61±0.68毫米。一项基于所提出框架研究髋臼杯方向术后评估的临床研究显示，前倾角和倾斜角的平均精度分别为1.2°±0.9°和1.6°±1.4°。每张X线片的描绘耗时不到一分钟。
尽管需要进一步验证，但初步结果表明所提出的框架在无图像全髋关节置换术中具有潜在的临床适用性。
