Validation of three-dimensional model-based tibio-femoral tracking during running
Validation of three-dimensional model-based tibio-femoral tracking during running
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DOI：
10.1016/j.medengphy.2008.03.003
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发表时间：
2009-01-01
影响因子：
2.2
通讯作者：
Tashman, Scott
中科院分区：
文献类型：
--
作者：
Anderst, William;Zauel, Roger;Tashman, Scott
本研究的目的是确定一种基于放射学模型的跟踪技术的准确性，该技术可以测量跑步过程中胫骨-股关节的三维体内运动。将钽珠植入3例患者的股骨和胫骨，植入后进行计算机断层扫描（CT）。受试者在位于双翼放射照相系统内的跑步机上以2.5米/秒的速度奔跑，同时以每秒250帧的速度获取图像。确定三维植入头的位置，并将其作为衡量基于模型的跟踪准确性的“金标准”。基于模型的跟踪技术优化了通过双翼x线系统获得的x线照片与由体渲染CT模型创建的数字重建x线照片之间的相关性。准确度定义为测量系统偏差、精度和均方根误差。结果报告了个体骨跟踪和临床相关的胫骨-股骨关节平移和旋转（关节运动学）。关节运动学精度为：基于模型的跟踪测量关节静态方向精度为0.2度及以上，静态关节位置精度为0.2 mm及以上。基于模型的动态关节旋转跟踪精度分别为屈伸、内外旋转和ab内收的0.9 +/- 0.3度、0.6 +/- 0.3度和0.3 +/- 0.1度。在测量动态关节平移时，基于模型的跟踪精度在中外侧、近端-远端和前后方向分别为0.3 +/- 0.1 mm、0.4 +/- 0.2 mm和0.7 +/- 0.2 mm。高速双翼x线摄影和基于体积模型的跟踪相结合，在体内动态膝关节运动中实现了出色的准确性，而无需侵入性头部植入。(c) 2008年合同。Elsevier Ltd.出版。版权所有。
The purpose of this study was to determine the accuracy of a radiographic model-based tracking technique that measures the three-dimensional in vivo motion of the tibio-femoral joint during running. Tantalum beads were implanted into the femur and tibia of three subjects and computed tomography (CT) scans were acquired after bead implantation. The subjects ran 2.5 m/s on a treadmill positioned within a biplane radiographic system while images were acquired at 250 frames per second. Three-dimensional implanted bead locations were determined and used as a "gold standard" to measure the accuracy of the model-based tracking. The model-based tracking technique optimized the correlation between the radiographs acquired via the biplane X-ray system and digitally reconstructed radiographs created from the volume-rendered CT model. Accuracy was defined in terms of measurement system bias, precision and root-mean-squared (rms) error. Results were reported in terms of individual bone tracking and in terms of clinically relevant tibio-femoral joint translations and rotations (joint kinematics). Accuracy for joint kinematics was as follows: model-based tracking measured static joint orientation with a precision of 0.2 degrees or better, and static joint position with a precision of 0.2 mm or better. Model-based tracking precision for dynamic joint rotation was 0.9 +/- 0.3 degrees, 0.6 +/- 0.3 degrees, and 0.3 +/- 0.1 degrees for flexion-extension, external-internal rotation, and ab-adduction, respectively. Model-based tracking precision when measuring dynamic joint translation was 0.3 +/- 0.1 mm, 0.4 +/- 0.2 mm, and 0.7 +/- 0.2 mm in the medial-lateral, proximal-distal, and anterior-posterior direction, respectively. The combination of high-speed biplane radiography and volumetric model-based tracking achieves excellent accuracy during in vivo, dynamic knee motion without the necessity for invasive bead implantation. (C) 2008 IPEM. Published by Elsevier Ltd. All rights reserved.