Objectives:

Raster-stereography (RST) has been developed as an alternative to plain radiography to avoid repeated radiation doses. The aim was to compare retrospectively evaluated RST with radiography in adolescent idiopathic scoliosis and to determine its validation in sagittal, coronal and axial plane parameters.

Materials and Methods:

After retrospective evaluation of the patients with biplanar radiography (EOS) and RST scans, 31 patients were included. Height (trunk height), pelvic parameters (pelvic obliquity, pelvic tilt, sacral slope, pelvic inclination), sagittal plane (thoracic kyphosis, lumbar lordosis, T1 slope, sagittal imbalance), coronal plane (main Cobb angle, apical deviation, T1 tilt) and axial plane (rotation) parameters were measured in EOS and RST, and the values were compared for examining their relationships with each other.

Results:

In trunk length measurements, a high correlation was observed between RST and EOS (r=0.940; p<0.001). In coronal Cobb angle, apex-midline distance, pelvic obliquity and coronal malalignment (r=0.628, r=0.832, r=0.815, r=0.577; p<0.001, respectively), a moderate-high correlation was found. There was a moderate correlation in thoracic kyphosis and sagittal malalignment (r=0.562, r=0.452; p=0.001) while there was no correlation in lumbar lordosis (r=-0.276; p>0.05). A weak correlation was found in vertebral rotation measurements (r=0.377; p=0.004).

Conclusion:

RST was successful in understanding the deformity and in coronal plane analysis. Further studies will determine its utility in the analysis of sagittal and axial planes. It is possible to use RST as a complement to radiography for patients undergoing scoliosis rehabilitation, especially in the growing age, to avoid repeated radiation exposure. Further studies are warranted to determine follow-up protocols.

Keywords: EOS Radiography, Rasterstereography, Surface Topography, Adolescent Idiopathic Scoliosis, Radiation-free Imaging Methods