Reliability of 2 Smartphone Applications for Cobb Angle Measurement in Scoliosis

Abstract The Cobb angle is an important indicator for judging the severity of scoliosis. However, the segmentation and corner marking methods based on deep learning have problems such as target area segmentation and corner detection blur in the X-ray Cobb angle measurement. In this paper, a new convex hull algorithm to detect the corners and a mask generation strategy are proposed to improve the accuracy of Cobb angle recognition. On this basis, the Cobb angle measurement method is presented to identify and segment the target area based on U-net network, and then combine the new convex hull algorithm to detect corners and mask generation strategies. A total of 68 corner points were marked on 17 vertebrae, and the corner points detected by the markers were used to calculate the Cobb angle. The experimental results have proved that the U-net based measurement method could effectively improve the corner detection accuracy on the basis of segmentation, thereby reducing the calculation error of the Cobb angle. The Cobb mean absolute error (AMAE) is 9.2832°, and the symmetric mean absolute percentage error (SMAPE) is 21.675%, which achieved a relatively good result compared with the measurement by professional orthopaedist in error.

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Effect of Spinal Bracing on Curve Magnitude in Coronal and Axial Planes in Adolescent Scoliosis Utilising EOS Imaging.

10.21203/rs.3.rs-596556/v1 ◽

2021 ◽

Author(s):

Simon Gatehouse ◽

Maree Izatt ◽

Robert Labrom ◽

Geoffrey Askin ◽

Caroline Grant ◽

...

Keyword(s):

Cobb Angle ◽

Angle Measurement ◽

Vertebral Rotation ◽

Curve Progression ◽

Brace Treatment ◽

Eos Imaging ◽

Cobb Angle Measurement ◽

Axial Vertebral Rotation ◽

The Mean ◽

Significant Change

Abstract Purpose. This study aimed to investigate the efficacy of spinal bracing in treating progressive scoliosis deformity utilizing EOS (bi-planer) imaging and SterEOS reconstruction software. Methods. EOS images of scoliosis patients being treated with bracing were obtained both in and out of their brace. These images were processed using SterEOS software to allow 3D representation, which was then compared to traditional coronal 2D parameters. Between January 2019 and January 2020, 29 patients were recruited for participation. Of these participants, 25 had a single episode of EOS imaging out of and in their brace. Additionally, 19 of the 25 participants had further episodes of EOS imaging within the study period, separated by mean 144+/-44 days. This allowed a total of 44 EOS single scan episodes for parameter analysis out of, and in the brace. Longitudinal analysis was also performed on the 19 patients who had sequential scans.Results. Participants were mean 13.8±1.1 years old at the first scan. Coronal 2D parameters, specifically Cobb Angle measurement, were accurately reproducible with SterEOS 3D measurements. Across all EOS scans (n=44) the mean major coronal curve measurement was 42.3±13.3° out of brace and 37.2±13.8° in the brace. This produced a mean correction of 4.6±4.4° (p<0.05). The correction achieved in this cohort with bracing appeared more modest than those reported in previous studies using traditional 2D coronal curve measurements1–3. The mean axial vertebral rotation (AVR) was 10.6±7.1° out of the brace and 9.6±6.8° in the brace, with a mean correction of 1.4±5.3°(p=0.14). The current study results suggested no significant change in axial vertebral rotation with brace treatment. Notably, in 17 of the 44 AVR measured, the differences were negative. That is, the AVR worsened in the brace. There was a significant moderate correlation between 3D coronal Cobb angle measured and AVR measured out of the brace for all curves. However, the change in Cobb and change in AVR with bracing did not correlate.Over sequential EOS episodes (n=19), there appeared no significant progression of 3D parameters, interpreted as the brace preventing curve progression.Conclusions. There appeared to be a consistent reduction in the scoliosis Cobb angle of the major curve with brace treatment. AVR demonstrated no significant change with bracing, with instances of worsening of AVR in the brace, which was not reflected by Cobb angle measurement. Despite this, bracing appears to have been effective with limited curve progression in sequential scans, though not in the anticipated manner of immediate in-brace curve correction.

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