Can magnetic resonance imaging-derived bone models be used for accurate motion measurement with single-plane three-dimensional shape registration?
Can magnetic resonance imaging-derived bone models be used for accurate motion measurement with single-plane three-dimensional shape registration?
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DOI：
10.1002/jor.20355
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发表时间：
2007-07-01
影响因子：
2.8
通讯作者：
Banks, Scott A.
中科院分区：
文献类型：
--
作者：
Moro-oka, Taka-aki;Hamai, Satoshi;Banks, Scott A.
本研究的目的是利用磁共振成像（MRI）和计算机断层扫描（CT）创建的骨骼模型，比较单平面放射成像投影的三维（3D）运动学测量结果。MRI之所以有吸引力，是因为它没有电离辐射，但与CT相比，几何场畸变和较差的骨对比降低了模型的保真度。我们通过MRI和CT建立了三名健康志愿者的膝关节模型，并进行了三次定量比较。首先，测量了MRI和ct衍生的骨模型表面之间的差异。其次，对深蹲活动的x射线图像序列的骨骼模型进行形状匹配运动测量。第三，生成已知姿态的合成x射线图像，再次进行形状匹配；运动学结果的差异以均方根误差（RMS）来量化。股骨和胫骨的CT和MRI模型表面的平均差异分别为-0.08 mm和-0.14 mm。对比mri骨模型和ct骨模型的匹配结果，6个运动学参数中有3个存在显著差异。在MRI模型中，矢状面平移的胫骨股骨位姿的均方根误差为0.74 mm，中外侧平移为2.0 mm，所有旋转的均方根误差为1.4度。矢状面平移的平均均方根误差为0.53 mm，中外侧平移的平均均方根误差为1.6 mm， CT模型所有旋转的平均均方根误差为0.54度。基于模型的形状匹配的单平面x射线成像提供了足够精确的运动学测量，可以使用MRI或ct衍生的骨骼模型来评估膝关节运动。然而，在使用mri衍生的骨模型时应格外小心，因为模型的不准确性会影响形状匹配结果的质量。(c) 2007年骨科研究学会。Wiley期刊公司出版。
The purpose of this study was to compare three-dimensional (3D) kinematic measurements from single-plane radiographic projections using bone models created from magnetic resonance imaging (MRI) and computed tomography (CT). MRI is attractive because there is no ionizing radiation, but geometric field distortion and poor bone contrast degrade model fidelity compared to CT. We created knee bone models of three healthy volunteers from both MRI and CT and performed three quantitative comparisons. First, differences between MRI- and CT-derived bone model surfaces were measured. Second, shape matching motion measurements were done with bone models for X-ray image sequences of a squat activity. Third, synthetic X-ray images in known poses were created and shape matching was again performed. Differences in kinematic results were quantified in terms of root mean square (RMS) error. Mean differences between CT and MRI model surfaces for the femur and tibia were -0.08 mm and -0.14 mm, respectively. There were significant differences in three of six kinematic parameters comparing matching results from MRI-derived bone models and CT-derived bone models. RMS errors for tibiofemoral poses averaged 0.74 mm for sagittal translations, 2.0 mm for mediolateral translations, and 1.4 degrees for all rotations with MRI models. Average RMS errors were 0.53 mm for sagittal translations, 1.6 mm for mediolateral translations, and 0.54 degrees for all rotations with the CT models. Single-plane X-ray imaging with model-based shape matching provides kinematic measurements with sufficient accuracy to assess knee motions using either MRI- or CT-derived bone models. However, extra care should be taken when using MRI-derived bone models because model inaccuracies will affect the quality of the shape matching results. (c) 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.