Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada.
Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada.
Med Biol Eng Comput. 2019 Oct;57(10):2115-2128. doi: 10.1007/s11517-019-02015-9. Epub 2019 Jul 31.
Adolescent idiopathic scoliosis (AIS) is a three-dimensional (3D) spinal deformity. Current practice uses the Cobb method to measure spinal severity on postero-anterior (PA) radiographs. This method may underestimate spinal deformity and exposes patients to ionizing radiation, increasing the risk of cancer. This paper reports a new 3D ultrasound method using the voxel-based reconstruction technique with bilinear interpolation to reconstruct a 3D spinal image and measure true spinal curvature on the plane of maximal curvature (PMC). Axial vertebral rotation (AVR) was measured on the 3D image and utilized to estimate the PMC. In vitro phantom experiments and in vivo clinical study were conducted to evaluate reconstruction accuracy and measurement reliability. The in vitro study showed a high accuracy of the reconstruction of vertebrae with the mean absolute difference (MAD) < 3 mm. The in vitro and in vivo measurements of AVR were reliable (> 0.90). The in vivo study also showed high intra- and inter-rater reliabilities of the PA and PMC Cobb angle measurements with ICC values > 0.90 and MADs within the clinical accepted tolerances. The PMC Cobb angles were up to 7° greater than their corresponding PA Cobb angles. This method demonstrated a non-ionizing radiation method to assess the actual severity of AIS. Graphical abstract Adolescent idiopathic scoliosis (AIS) is a lateral curvature of spine with vertebral rotation. Using the Cobb method to measure spinal severity on postero-anterior (PA) radiographs may under estimate its severity.
青少年特发性脊柱侧凸（AIS）是一种三维（3D）脊柱畸形。目前的临床实践使用 Cobb 法在前后位（PA）X 光片上测量脊柱的严重程度。这种方法可能会低估脊柱畸形的程度，并使患者暴露在电离辐射下，增加患癌症的风险。本文报告了一种新的 3D 超声方法，使用体素重建技术和双线性内插来重建 3D 脊柱图像，并在最大曲率平面（PMC）上测量真实的脊柱曲率。在 3D 图像上测量轴向椎体旋转（AVR），并利用其来估计 PMC。进行了体外幻影实验和体内临床研究，以评估重建准确性和测量可靠性。体外研究表明，重建椎体的准确性很高，平均绝对差值（MAD）<3 毫米。体外和体内的 AVR 测量具有很高的可靠性（>0.90）。体内研究还表明，PA 和 PMC Cobb 角测量的内部和内部评估者之间具有很高的可靠性，ICC 值>0.90，MAD 在临床可接受的公差范围内。PMC Cobb 角比相应的 PA Cobb 角大 7°。该方法证明了一种非电离辐射方法来评估 AIS 的实际严重程度。
