Global geometric torsion estimation in adolescent idiopathic scoliosis
Global geometric torsion estimation in adolescent idiopathic scoliosis
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DOI：
10.1007/s11517-013-1132-8
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发表时间：
2014-04-01
影响因子：
3.2
通讯作者：
Parent, Stefan
中科院分区：
文献类型：
--
作者：
Kadoury, Samuel;Shen, Jesse;Parent, Stefan
已经进行了几次尝试来测量青少年特发性脊柱侧凸（AIS）的几何扭转并量化脊柱的三维（3D）变形。然而，这些方法对解剖结构的3D建模中的不精确性敏感，并且只能捕获椎骨处的局部效果，忽略了区域水平的全局效果，因此从未被广泛用于跟踪畸形的进展。这项工作的目的是评估一种新的几何扭转描述符的相关性的基础上的参数化建模的脊柱曲线作为脊柱侧凸的三维指标。首先，锚定在先验统计分布的基于图像的方法被用来从双平面X射线重建脊柱的3D。然后使用一种技术估计测量脊柱扭曲效应的几何扭转，该技术利用以不同脊柱区域中的中性椎骨为中心的参数曲线拟合来近似局部弧长。我们首先评估的方法与模拟实验，证明该方法的鲁棒性对添加噪声和重建不准确。还进行了一项涉及65名表现出不同类型畸形的脊柱侧弯患者的试点研究。结果表明，该方法是能够区分不同类型的变形的基础上，这种新的3D指数评价的主要胸部和胸腰椎/腰椎区域。这表明，通过参数脊柱曲线拟合建模的几何扭转是一种稳健的工具，可用于量化AIS的3D变形，并可能用作对3D形状进行分类的指标。
Several attempts have been made to measure geometrical torsion in adolescent idiopathic scoliosis (AIS) and quantify the three-dimensional (3D) deformation of the spine. However, these approaches are sensitive to imprecisions in the 3D modeling of the anatomy and can only capture the effect locally at the vertebrae, ignoring the global effect at the regional level and thus have never been widely used to follow the progression of a deformity. The goal of this work was to evaluate the relevance of a novel geometric torsion descriptor based on a parametric modeling of the spinal curve as a 3D index of scoliosis. First, an image-based approach anchored on prior statistical distributions is used to reconstruct the spine in 3D from biplanar X-rays. Geometric torsion measuring the twisting effect of the spine is then estimated using a technique that approximates local arc-lengths with parametric curve fitting centered at the neutral vertebra in different spinal regions. We first evaluated the method with simulated experiments, demonstrating the method's robustness toward added noise and reconstruction inaccuracies. A pilot study involving 65 scoliotic patients exhibiting different types of deformities was also conducted. Results show the method is able to discriminate between different types of deformation based on this novel 3D index evaluated in the main thoracic and thoracolumbar/lumbar regions. This demonstrates that geometric torsion modeled by parametric spinal curve fitting is a robust tool that can be used to quantify the 3D deformation of AIS and possibly exploited as an index to classify the 3D shape.