Abstract: Objective To evaluate the consistency of a new weight-bearing three-dimensional imaging(WR-3D)technology in measuring Cobb angles of adolescent idiopathic scoliosis(AIS)patients with traditional standing X-ray films. Methods From July to October, 2025, a total of 52 AIS patients have been enrolled at Qilu Hospital of Shandong University and underwent both standing full-spine X-ray and weight-bearing three-dimensional imaging examinations simultaneously. Pearson correlation analysis was used to assess the linear association between the two methods. Bland-Altman analysis was performed to calculate the mean bias and 95% limits of agreement, and the intraclass correlation coefficient(ICC)was used to evaluate the reliability. Paired t-test was used to test for systematic bias, and Cohens d was calculated to assess the effect size. Results There was a significant positive correlation between the measurements of WR-3D and traditional X-ray(r=0.977, P<0.001). Bland-Altman analysis showed a mean bias of -1.37°(95%CI: -7.32° to 4.58°), and the majority of data points(51/52)were within the limits of agreement. The ICC indicated excellent consistency(ICC=0.973, 95% CI: 0.954 to 0.985). Paired t-test suggested a statistically significant difference(P=0.002), but the effect size was moderate(Cohens d=0.450). Conclusion The WR-3D imaging system has excellent consistency with traditional X-ray in measuring Cobb angles of AIS patients, and the minor systematic bias has no significant clinical significance. This technique, combined with its three-dimensional, weight-bearing, and low-radiation advantages, provides a reliable new clinical tool for the precise assessment of scoliosis.

Key words: Adolescent idiopathic scoliosis, Cobb angle, Automatic measurement, Three-dimensional imaging, Weight-bearing imaging, Consistency