Zhihui Chang BMedSc, MMed, Presenter: Nothing to Disclose

Xiaoli Yin, Abstract Co-Author: Nothing to Disclose

Zhaoyu Liu, Abstract Co-Author: Nothing to Disclose

Determine inter- and intraobserver variability of computed tomography (CT) in evaluating the femoral neck anteversion（FNA） and acetabular index（AI） of children with developmental dysplasia of the hip（DDH）using three-dimensional CT.

This study was approved by the local Institutional Review Board of Shengjing Hospital of China Medical University.Fourty-eight DDH patients with a total of seventy-six dislocated hips enrolled in this study. A 64-MDCT scanner (Brilllance64, Philips Healthcare) was used for all examinations.The area of scanning include pelvis and distal femur. Two radiologists independently measured the FNA and AI using Mxview Workspace（Philips）. One of the radiologists repeated the evaluation after an interval of at least 4 weeks.Concordance correlation coefficients (CCCs) and Bland-Altman plots were used to assess inter- and intraobserver agreement.

For FNA measurements, the 95% limits of agreement were -30.74°and 48.56°,and -29.91° and 46.16° for intra- and inter-observer variability, respectively. For AI measurements,the 95% limits of agreement were -13.27° and 25.93°, and -15.03° and 26.17° for intra- and inter-observer variability, respectively. High CCCs (0.949–0.990) were observed in both FNA and AI measurement for inter- and intraobserver agreement.

CT measurements in DDH patients were found to be reproducible indicating a good visualization of dislocated hip and an accurate definition of the measurement protocol.

Using 3DCT with Mxview Workspace, intra- and interobserver reproducibility were excellent in evaluating femoral neck anteversion and acetabular index for children with developmental dysplasia of hip.

Chang, Z, Yin, X, Liu, Z, Reproducibility in the Assessment of Femoral Neck Anteversion and Acetabular Index by CT for Children's Developmental Dysplasia of the Hip.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11003876.html