School of Materials, The University of Manchester, Manchester, M1 7HS, UK.
School of Engineering, Newcastle University, Newcastle upon Tyne, England NE1 7RU, UK.
Comput Biol Med. 2017 Oct 1;89:127-134. doi: 10.1016/j.compbiomed.2017.07.026. Epub 2017 Aug 1.
This paper describes a simple protocol for measuring the joint space of the rheumatoid arthritic (RA) wrist from projection radiographs. The protocol is implemented using a computer algorithm based upon the Interactive Data Language platform. The computerized algorithm features a user-friendly graphical interface to aid the operator to measure joint space parameters, namely distance and area, of the wrist vertebral morphometry at the radiocarpal region. Dual-energy X-ray absorptiometry (DXA) radiograph of a standard hand and wrist phantom was evaluated using the measurement protocol to determine the accuracy and precision of the protocol. The accuracy, parameterised by the systematic error, returned a mean of 5.20% for distance and is equal to 3.49% for area measurement. The precision of the measurement protocol, parameterised by the coefficient of variation (CV), for distance returned a mean of 1.96%; the CV for area measurement equals 2.1%. Three observers participated to investigate the repeatability (intra-observer) and reproducibility (inter-observer) of the measurement protocol, parameterised by the CV, using DXA radiographs from a healthy volunteer and a RA patient. The inter-observer repeatability for distance measurement for the respective observers returned mean values of 10.9%, 7.7% and 11.4% for the healthy wrist. However, the results revealed improved repeatability for the RA wrist; the CV for the respective observers returned mean values of 7.7% 7.1% and 10.0%. The inter-observer repeatability for area measurement for the respective observers returned mean values of 10.2%, 7.1% and 10.1% for the healthy wrist. However, the results revealed improved repeatability (in two out of the three observers) for the RA wrist; the CV for the respective observers returned mean values of 6.8% 6.5% and 10.8%. Student's t-test analysis of the intra-observer repeatability revealed that the measurements of distance and area were generally not intra-observer sensitive. On the other hand, student's t-test analysis of the inter-observer reproducibility revealed that half of the distance measurements were inter-observer sensitive; whereas the remaining were not. Similar findings were obtained for area measurements. Overall the results reveal that the variabilities in accuracy and precision tests and the repeatability and reproducibility tests were typically 10% or less. These findings, in addition to the versatility and simplicity of the digital image analysis protocol, lend to the potential of using the protocol to complement the acquisition of bone mineral density data derived from DXA for diagnosing the progression of RA in patients.
本文描述了一种从投影射线照片测量类风湿关节炎 (RA) 腕关节关节间隙的简单方案。该方案是使用基于交互式数据语言平台的计算机算法实现的。计算机算法具有用户友好的图形界面，可帮助操作人员测量腕部椎体形态学在桡腕区域的关节间隙参数，即距离和面积。使用测量方案评估了标准手和腕部幻影的双能 X 射线吸收法 (DXA) 射线照片，以确定方案的准确性和精密度。参数为系统误差的准确性，距离返回的平均值为 5.20%，面积测量的准确性等于 3.49%。参数为变异系数 (CV) 的测量方案的精密度，距离返回的平均值为 1.96%；面积测量的 CV 等于 2.1%。三位观察者参与了使用健康志愿者和 RA 患者的 DXA 射线照片调查测量方案的重复性（观察者内）和可重复性（观察者间），参数为 CV。对于健康手腕，相应观察者的距离测量的观察者内重复性的平均值分别为 10.9%、7.7%和 11.4%。然而，结果表明 RA 手腕的重复性得到了改善；相应观察者的 CV 的平均值分别为 7.7%、7.1%和 10.0%。对于健康手腕，相应观察者的面积测量的观察者间重复性的平均值分别为 10.2%、7.1%和 10.1%。然而，结果表明 RA 手腕的重复性（在三位观察者中的两位）得到了改善；相应观察者的 CV 的平均值分别为 6.8%、6.5%和 10.8%。观察者内重复性的学生 t 检验分析表明，距离和面积的测量通常对观察者内不敏感。另一方面，观察者间可重复性的学生 t 检验分析表明，一半的距离测量对观察者间敏感；而其余的则不敏感。面积测量也得到了类似的发现。总体而言，结果表明，准确性和精密度测试以及重复性和可重复性测试的变异性通常为 10%或更低。除了数字图像分析协议的多功能性和简单性外，这些发现还使得该协议有可能用于补充双能 X 射线吸收法 (DXA) 获得的骨密度数据，以诊断患者 RA 的进展。
