Evaluation of diagnostic accuracy and image quality of EOS imaging system in hip assessment with refer to computed tomography

Abstract

Aim: This study evaluates the accuracy of the EOS imaging system in assessing pre- and post- operative hip abnormalities compared to the reference standard CT scan, focusing on EOS image quality and patient experience. Materials and Methods: (i) A systematic review and meta-analysis were conducted to compare EOS accuracy with CT for measuring native and prosthetic hip parameters in adolescents and adults. (ii) A prospective analysis of 10 patients assessed EOS diagnostic accuracy for native hips with acetabular dysplasia compared to CT. (iii) A retrospective analysis of 100 patients evaluated mechanical axis measurements by EOS and digital radiographs (DR). (iv) A retrospective analysis of 30 patients reviewed patient experience with CT and EOS. In (i), reliability coefficients were normalised with Fisher’s Z and presented with effect size and 95% confidence intervals in a forest plot. For (ii), three observers independently measured acetabular version, inclination, femur length and spinopelvic parameters on CT, while two assessed the same parameters on EOS. In (iii), three observers scored DR and EOS acetabular morphology according to modified European diagnostic image quality criteria. In (iv), participants completed questionnaires on their experiences. Results: (i) The average correlation across studies was high (r = 0.86, 95% CI = 0.80–0.90, p < 0.001). (ii) EOS showed good agreement with CT for spinopelvic parameters and femur length pre- and post-operatively and acetabular inclination pre-operatively, but lower agreement for acetabular version and pre-operative inclination. (iii) EOS demonstrated high AC1, sensitivity, and AUCs for mechanical axis imaging compared to DR. (iv) Most patients preferred CT over EOS. Conclusion: EOS shows good inter-observer agreement for spinopelvic parameters and femur length compared to CT but poor agreement for acetabular version and inclination. Patients prefer CT, possibly due to familiarity. However, EOS offers better mechanical axis image quality than digital radiographs.