Lee Dongwoon, Li Zhi, Sohail Qazi Zain, Jackson Ken, Fiume Eugene, Agur Anne
a Department of Computer Science , University of Toronto , Toronto , Ontario , Canada.
Comput Methods Biomech Biomed Engin. 2015;18(13):1474-84. doi: 10.1080/10255842.2014.917294. Epub 2014 May 21.
Pennation angle (PA) is an important property of human skeletal muscle that plays a significant role in determining the force contribution of fascicles to skeletal movement. Two-dimensional (2D) ultrasonography is the most common approach to measure PA. However, in principle, it is challenging to infer knowledge of three-dimensional (3D) architecture from 2D assessment. Furthermore, architectural complexity and variation impose more difficulties on reliable and consistent quantification of PA. Thus, the purpose of our study is to provide accurate insight into the correspondence between 2D assessment and the underlying 3D architecture. To this end, a 3D method was developed to directly quantify PA based on 3D architectural data that were acquired from cadaveric specimens through dissection and digitization. Those data were then assessed two-dimensionally by simulating ultrasound imaging. To achieve consistency over intermuscular variation, our proposed 3D method is based on the geometric analysis of fascicle attachment. Comparative results show a wide range of differences (1.1-47.1%) between 2D and 3D measurements. That is, ultrasound can under- or over-estimate PA, depending on the architecture.
羽状角（PA）是人体骨骼肌的一项重要特性，在确定肌束对骨骼运动的力贡献方面发挥着重要作用。二维（2D）超声检查是测量PA最常用的方法。然而，原则上，从二维评估推断三维（3D）结构的信息具有挑战性。此外，结构的复杂性和变异性给PA的可靠和一致量化带来了更多困难。因此，我们研究的目的是深入了解二维评估与潜在三维结构之间的对应关系。为此，开发了一种三维方法，基于通过解剖和数字化从尸体标本获取的三维结构数据直接量化PA。然后通过模拟超声成像对这些数据进行二维评估。为了在肌肉间变异中实现一致性，我们提出的三维方法基于肌束附着的几何分析。比较结果显示二维和三维测量之间存在广泛差异（1.1 - 47.1%）。也就是说，超声可能低估或高估PA，这取决于结构。
