这就是阿尔法角度
Seper Ekhtiari1, Olivia Fairhurst2, Lily Mainwaring2
1Division of Orthopaedic Surgery, University of Toronto, Toronto, Ontario, Canada.
The Journal of bone and joint surgery. American volume
|September 16, 2024
概括
阿尔法角测量可能不可靠,特别是用X光片. 先进的3D成像提供了更准确的病变量化,提高了临床相关性.
科学领域:
- 整形外科 整形外科 整形外科
- 放射学 放射学是一门学科.
- 生物医学工程 生物医学工程
背景情况:
- 阿尔法角是诊断股骨支柱入 (FAI) 的关键指标.
- 最初使用磁共振成像 (MRI) 定义,其测量已经适应在各种成像模式.
- 文学往往依赖于放射图,这在准确的α角量化方面提出了挑战.
研究的目的:
- 在不同的成像技术中评估alpha角度测量的可靠性.
- 为了突出传统方法在捕捉病变的3D性质方面的局限性.
- 探索先进的成像技术的潜力,以更准确地评估alpha角度.
主要方法:
- 审查关于阿尔法角度测量技术的现有文献.
- 分析来自X光,超声波和MRI的测量可靠性.
- 讨论3D成像模式和手术内/动态成像选项.
主要成果:
- 阿尔法角测量在放射和超声波上特别不可靠.
- 建议在多个X线图视图上使用"最适合的圆圈"方法来减轻错误.
- 应该避免"眼球"或从放射图片中估计α角.
- 腿部病变是动态的3D问题,不能被单一的角度充分定义.
结论:
- 传统的阿尔法角度测量方法,特别是X射线图,具有显著的局限性.
- 凸轮病变的动态和3D性质需要先进的成像技术.
- 现代3D和动态成像提供了更精确和临床相关的α角量化.
相关概念视频
Two-Dimensional Force System
888
A two-dimensional system in mechanical engineering involves the analysis of motion and forces in a plane. A two-dimensional force vector can be resolved into its components as:
888
Unsymmetric Bending - Angle of Neutral Axis
287
Unsymmetrical bending occurs when a structural member is subjected to bending moments in a plane that does not align with the member's principal axes. This scenario typically arises in beams and other structural components when loads are applied at non-ideal angles, introducing complexities in stress analysis.
When a bending moment is applied at an angle θ concerning the vertical axis of a symmetrical member, it can be resolved into components along the member's principal...
When a bending moment is applied at an angle θ concerning the vertical axis of a symmetrical member, it can be resolved into components along the member's principal...
287
Angle of Twist: Problem Solving
267
An electric motor applies a torque of 700 N·m to an aluminum shaft, triggering a stable rotation. Two pulleys, B and C, are subjected to torques of 300 N·m and 400 N·m, respectively. The modulus of rigidity is provided as 25 GPa. With the knowledge of the length and diameter of each segment, the twist angle between the two pulleys can be computed. First, a section cut is made between pulleys B and C, and the cut cross-section is analyzed using a free-body diagram. Given that the...
267
Design Example: Traverse Angle Computations
61
Traverse angle computations are a critical component of surveying, used to compute the internal angles within a closed traverse. A traverse consists of a series of connected lines forming a closed loop, often used for land boundary delineation or mapping. Calculating the internal angles ensures accuracy in the traverse geometry and is essential for checking survey data integrity.The process begins with known azimuths and bearings of the traverse sides. Internal angles at each vertex are...
61
Relative Motion Analysis using Rotating Axes-Problem Solving
394
Consider a crane whose telescopic boom rotates with an angular velocity of 0.04 rad/s and angular acceleration of 0.02 rad/s2. Along with the rotation, the boom also extends linearly with a uniform speed of 5 m/s. The extension of the boom is measured at point D, which is measured with respect to the fixed point C on the other end of the boom. For the given instant, the distance between points C and D is 60 meters.
Here, in order to determine the magnitude of velocity and acceleration for point...
Here, in order to determine the magnitude of velocity and acceleration for point...
394
Two-Dimensional Force System: Problem Solving
552
Solving problems related to two-dimensional force systems is an essential aspect of mechanics and engineering. By applying the principles of vector analysis and force equilibrium, one can determine the effect of multiple forces acting on an object in a two-dimensional space.
The first step to solving a two-dimensional force system problem is to draw a free-body diagram of the object under consideration. This diagram helps identify all the external forces acting on the object, including their...
The first step to solving a two-dimensional force system problem is to draw a free-body diagram of the object under consideration. This diagram helps identify all the external forces acting on the object, including their...
552


