Centre of Orthopaedic & Trauma Research, University of Adelaide, Adelaide, South Australia, Australia.
Medical Device Research Institute, College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia.
J Orthop Res. 2022 Feb;40(2):396-408. doi: 10.1002/jor.25051. Epub 2021 Apr 30.
The objectives of this study were to (1) develop a semiautomated method to obtain lesion volume and bone mineral density (BMD) in terms of Hounsfield units from pelvic computed tomography (CT) scans in three regions of interest, and (2) assess accuracy and reliability of the method based on cadaveric CT scans. Image artefacts due to metal implants reduce CT clarity and are more severe with more than one implant in situ. Therefore, accuracy and reliability tests were performed with varying numbers of total hip arthroplasties implanted. To test the accuracy of lesion size measurements, microcomputed tomography was used as a reference. Mean absolute error ranged from 36 to 284 mm after five measurements. Intra- and inter-operator reliability of the entire method was measured for a selection of parameters. All coefficient of variation values were good to excellent for CT scans of the native pelvic anatomy and a CT scans of the same pelvis with one and two implants in situ. Accuracy of quantifying lesion volume decreased with decreasing CT image clarity by 0.6%-3.6% mean absolute relative error. Reliability of lesion volume measurement decreased with decreasing CT clarity. This was also the case for reliability of BMD measurements in the region most disrupted by metal artefact. The presented method proposes an approach for quantifying bone loss which has been proven to be accurate, reliable, and clinically applicable.
（1）开发一种半自动方法，从三个感兴趣区域的骨盆 CT 扫描中获得病变体积和基于亨氏单位的骨密度（BMD）；（2）基于尸体 CT 扫描评估该方法的准确性和可靠性。由于金属植入物引起的图像伪影降低了 CT 的清晰度，而且随着原位植入的植入物数量增加，图像伪影会更加严重。因此，我们对不同数量的全髋关节置换进行了准确性和可靠性测试。为了测试病变大小测量的准确性，我们使用微计算机断层扫描作为参考。经过五次测量后，平均绝对误差范围为 36 至 284mm。我们选择了一些参数来测量整个方法的内部和操作员之间的可靠性。所有变异系数值对于原生骨盆解剖的 CT 扫描和原位植入一个和两个植入物的同一骨盆的 CT 扫描都是良好到极好的。通过 0.6%-3.6%的平均绝对相对误差，定量测量病变体积的准确性随着 CT 图像清晰度的降低而降低。随着 CT 清晰度的降低，病变体积测量的可靠性也降低。在受金属伪影干扰最严重的区域，BMD 测量的可靠性也是如此。本研究提出了一种定量骨丢失的方法，该方法已被证明具有准确性、可靠性和临床适用性。
