Journal Article

3D-modeling of the spine using EOS imaging system: Inter-reader reproducibility and reliability

Akbar, Michael, Germann, Thomas, Pepke, Wojciech, Weber, Marc-André, Rehm, Johannes, Spira, Daniel, Kauczor, Hans-Ulrich

2017

Overview

To retrospectively assess the interreader reproducibility and reliability of EOS 3D full spine reconstructions in patients with adolescent idiopathic scoliosis (AIS). 73 patients with mean age of 17 years and a moderate AIS (median Cobb Angle 18.2°) obtained low-dose standing biplanar radiographs with EOS. Two independent readers performed \"full spine\" 3D reconstructions of the spine with the \"full-spine\" method adjusting the bone contour of every thoracic and lumbar vertebra (Th1-L5). Interreader reproducibility was assessed regarding rotation of every single vertebra in the coronal (i.e. frontal), sagittal (i.e. lateral), and axial plane, T1/T12 kyphosis, T4/T12 kyphosis, L1/L5 lordosis, L1/S1 lordosis and pelvic parameters. Radiation exposure, scan-time and 3D reconstruction time were recorded. Interclass correlation (ICC) ranged between 0.83 and 0.98 for frontal vertebral rotation, between 0.94 and 0.99 for lateral vertebral rotation and between 0.51 and 0.88 for axial vertebral rotation. ICC was 0.92 for T1/T12 kyphosis, 0.95 for T4/T12 kyphosis, 0.90 for L1/L5 lordosis, 0.85 for L1/S1 lordosis, 0.97 for pelvic incidence, 0.96 for sacral slope, 0.98 for sagittal pelvic tilt and 0.94 for lateral pelvic tilt. The mean time for reconstruction was 14.9 minutes (reader 1: 14.6 minutes, reader 2: 15.2 minutes, p<0.0001). The mean total absorbed dose was 593.4μGy ±212.3 per patient. EOS \"full spine\" 3D angle measurement of vertebral rotation proved to be reliable and was performed in an acceptable reconstruction time. Interreader reproducibility of axial rotation was limited to some degree in the upper and middle thoracic spine due the obtuse angulation of the pedicles and the processi spinosi in the frontal view somewhat complicating their delineation.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adolescent / Analysis / Biology and Life Sciences / Diagnosis / Diagnostic imaging / Dosage / Female / Humans / Imaging, Three-Dimensional - methods / Kyphosis / Lymphocytes T / Male / Medical imaging / Medicine and Health Sciences / Observer Variation / Orthopedics / Patients / Physical Sciences / Radiation / Radiation effects / Radiographs / Radiography / Radiography - methods / Radiology / Reconstruction / Reliability analysis / Reproducibility / Reproducibility of Results / Research and Analysis Methods / Retrospective Studies / Sacrum / Scoliosis / Scoliosis - diagnostic imaging / Spine / Spine (lumbar) / Spine (thoracic) / Spine - diagnostic imaging / Surgery / Three dimensional models / Three-dimensional imaging / Tomography / Vertebra / Vertebrae / X rays