Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, Canada; Department of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada.
Department of Pediatrics, University of Alberta, Edmonton, AB, Canada.
Ultrasound Med Biol. 2024 Nov;50(11):1669-1673. doi: 10.1016/j.ultrasmedbio.2024.07.002. Epub 2024 Aug 4.
Hip migration percentage (MP) measured on anteroposterior pelvis radiographs is the gold standard to assess the severity of hip displacement in children with cerebral palsy (CP). Repeated exposure of these children to ionizing radiation under a hip surveillance program is undesirable. Recently, a semi-automatic approach to measure MP on ultrasound (US) images was validated in a phantom study. This pilot in vivo study applied the previous phantom method and aimed to determine the reliability and accuracy of the MP.
Thirty-four children (23 boys and 11 girls) aged 8.9 ± 3.1 y old and diagnosed with CP were recruited. A total of 59 hips were scanned once, while 43 of these were scanned twice to evaluate the test-retest reliability. Two raters (R1 and R2) manually measured MP; procedures included selecting images of interest, cropping a region of interest and removing soft tissues on hip US images. Custom software was developed to measure MP automatically after the manual pre-image processing.
The intra-class correlation coefficients (ICC) for the test-retest (R1), intra-rater (R1) and inter-rater (R1 vs R2) reliabilities were 0.90, 0.94 and 0.82, respectively. The standard error of measurement of MP for all three evaluations was ≤3.0%. The mean absolute difference between MP and MP and the percentage of MP within clinical acceptance error of 10% for R1 and R2 were (R1: 6.2% ± 4.9%, 84.7%) and (R2: 7.6% ± 6.1%, 73.7%), respectively.
This study demonstrated that US scans were repeatable and MP could be measured reliably and accurately.
在骨盆前后位 X 线片上测量髋关节移行百分比（MP）是评估脑瘫（CP）患儿髋关节移位严重程度的金标准。对这些患儿进行髋关节监测计划下的电离辐射重复暴露是不理想的。最近，一种在超声（US）图像上半自动测量 MP 的方法在体模研究中得到了验证。本研究应用先前的体模方法，旨在确定 MP 的可靠性和准确性。
招募了 34 名年龄为 8.9 ± 3.1 岁且被诊断为 CP 的儿童。共对 59 髋进行了单次扫描，其中 43 髋进行了两次扫描，以评估测试-重测可靠性。两名评估者（R1 和 R2）手动测量 MP；过程包括选择感兴趣的图像、裁剪感兴趣区域并去除髋关节 US 图像上的软组织。在手动预处理图像后，开发了自定义软件来自动测量 MP。
测试-重测（R1）、内评估者（R1）和间评估者（R1 与 R2）可靠性的组内相关系数（ICC）分别为 0.90、0.94 和 0.82。所有三种评估的 MP 测量标准误差均≤3.0%。R1 和 R2 的 MP 和 MP 之间的平均绝对差值以及 MP 为临床可接受误差的 10%的百分比分别为（R1：6.2%±4.9%，84.7%）和（R2：7.6%±6.1%，73.7%）。
本研究表明，US 扫描具有可重复性，并且可以可靠和准确地测量 MP。
