Department of Orthopedic Surgery, University of California, San Francisco, San Francisco, California, U.S.A..
Department of Orthopaedics, The Ohio State University Wexner Medical Center, Columbus, Ohio.
Arthroscopy. 2019 Mar;35(3):734-740. doi: 10.1016/j.arthro.2018.10.119. Epub 2019 Feb 4.
To evaluate clinical measurements of glenoid bone loss based on 3-dimensional (3D) computed tomography (CT) and automatically segmented 3D reconstructions from Dixon fat-water magnetic resonance (MR) imaging.
Available CT and MR studies from 16 patients with recurrent anterior shoulder instability were retrospectively reviewed. Three-dimensional reconstructions were formed independently by 2 observers using freely available software and a simple threshold-based segmentation (3D Slicer, version 4.8.0; http://www.slicer.org). Bone loss was estimated with the perfect-circle method. Intra-user and interuser reproducibility was determined with intraclass correlation coefficients. Bland-Altman plots were used to evaluate the similarity between imaging modalities.
Differences between MR and CT estimates of bone loss ranged from 0% to 6%. The individual intraclass correlation coefficients showed good to excellent reliability, with intraobserver comparisons between MR- and CT-based bone loss estimates ranging from 0.94 to 0.99. Bland-Altman plots showed 95% confidence intervals from -5% to 6% for differences between MR and CT estimates, with 88% of all measurements (42 of 48) showing a less than 2% difference between MR and CT estimates.
The described methodology for obtaining an MR-based 3D reconstruction of the glenoid can evaluate glenoid bone loss similarly to the performance of a 3D CT reconstruction. The results may allow surgeons to simplify the preoperative imaging protocol for patients with recurrent shoulder stabilization and limit the number of shoulder CT scans.
Level III, retrospective therapeutic trial.
基于三维（3D）计算机断层扫描（CT）和自动分割的 3D 重建 Dixon 水脂磁共振（MR）成像，评估肩盂骨丢失的临床测量。
回顾性分析 16 例复发性肩关节前向不稳定患者的 CT 和 MR 检查。两名观察者分别使用免费软件和简单的基于阈值的分割（3D Slicer，版本 4.8.0；http://www.slicer.org）独立形成 3D 重建。采用完美圆法评估骨丢失。采用组内相关系数评估用户内和用户间的可重复性。Bland-Altman 图用于评估两种成像方式的相似性。
MR 和 CT 估计的骨丢失差异范围为 0%至 6%。个体内组内相关系数显示出良好至极好的可靠性，MR 和 CT 基于骨丢失估计的观察者内比较范围为 0.94 至 0.99。Bland-Altman 图显示，MR 和 CT 估计值之间的差异有 95%置信区间为-5%至 6%，88%（42/48）的测量值在 MR 和 CT 估计值之间的差异小于 2%。
本研究描述了一种基于 MR 的肩盂 3D 重建方法，可与 3D CT 重建的性能类似地评估肩盂骨丢失。该结果可能使外科医生简化复发性肩部稳定患者的术前成像方案，并减少肩部 CT 扫描的数量。
III 级，回顾性治疗试验。
