Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, University of Minnesota, 420 Delaware St SE, MMC 388, Minneapolis, MN 55455, USA; Department of Orthopaedic Surgery, University of Minnesota.
Department of Biomedical Engineering, University of Minnesota.
Spine J. 2022 Jun;22(6):1012-1015. doi: 10.1016/j.spinee.2022.01.016. Epub 2022 Feb 3.
Intraoperative stitched O-arm images are commonplace during spinal deformity correction surgeries; however, the accuracy of stitched images for measuring angular measures is unknown.
To examine the effect of radiographic parallax effect of stitched O-arm images by assessing the regional curve agreement with measurements from computed tomography (CT).
STUDY DESIGN/SETTING: Experimental radiographic study.
Four whole body cadavers (age: 81±14, sex: 2M/2F) and two fabricated spine model phantoms from surgical cases, one with extreme scoliosis and one normal spine, were utilized.
The limits of agreement for angular measures between CT (gold-standard) and intraoperative stitched fluoroscopic images were calculated. Further, intra- and inter-rater reliability was measured.
A series of adjacent anterior-posterior and lateral images were acquired cranial to caudal using an O-arm in three table configurations (standard position, off-axis in the coronal plane, and reverse Trendelenburg) and stitched manually. Regional angular measures were extracted, and the limits of agreement were calculated between each table position and CT using a Bland-Altman approach.
The observers displayed excellent inter-rater reliability across table positions (range: 0.944-0.989) and intra-rater reliability (0.979-0.995). The limits of agreement results showed a similar and better agreement was observed for the Standard and Reverse Trendelenburg than the Off-Axis position.
This work shows reliable regional curvature measurements can be calculated with good agreement with CT in common table positions, but care should be taken to ensure the patient is perpendicular to the X-rays, particularly in the lateral view.
术中缝合的 O 臂图像在脊柱畸形矫正手术中很常见；然而，缝合图像在测量角度方面的准确性尚不清楚。
通过评估与计算机断层扫描 (CT) 测量结果的区域曲线一致性，来检查缝合 O 臂图像的放射学视差效应对测量结果的影响。
研究设计/设置：实验性放射研究。
4 具全身尸体（年龄：81±14，性别：2 男/2 女）和 2 个来自手术病例的定制脊柱模型假人，一个有严重脊柱侧凸，一个正常脊柱，均用于本研究。
计算 CT（金标准）与术中缝合透视图像之间角度测量的一致性界限。此外，还测量了内部和外部观察者之间的可靠性。
使用 O 臂在三种台位配置（标准位置、冠状面偏置位置和反向特伦德伦堡位置）中从前向后采集一系列相邻的前后位和侧位图像，并手动缝合。提取区域角度测量值，并使用 Bland-Altman 方法计算每个台位与 CT 之间的一致性界限。
观察者在不同台位之间显示出极好的组内观察者间可靠性（范围：0.944-0.989）和组内观察者内可靠性（0.979-0.995）。一致性界限结果显示，标准和反向特伦德伦堡位置的结果比偏置位置的结果具有更好的一致性。
这项工作表明，在常见的台位中，可以可靠地计算出与 CT 具有良好一致性的区域曲率测量值，但应注意确保患者与 X 射线垂直，特别是在侧位。
