Abstract: Developmental dysplasia of the hip (DDH) is a common hip disease that seriously affects children's growth, impairing limb development and quality of life. Early diagnosis and treatment of DDH are crucial. Magnetic resonance imaging provides rich morphological information of the hip during development. Clinically DDH is usually diagnosed by visual inspection of the medical images, thus requiring high professional expertise of the doctors. In this work, a quantitative morphological evaluation method for examining the hip images and diagnosing DDH in children is proposed. This method evaluates morphological parameters of the hip quantitatively by automatically measuring the morphological parameters relevant to DDH pathological changes. The magnetic resonance images were first preprocessed, followed by segmentation of the femur and pelvis. A three-dimensional (3D) model of the hip joint was then reconstructed, which was then used to measure the center-edge angle (CEA), acetabular index (AI) and femoral neck anteversion (FNA)'s automatically with algorithms such as thickness search, 3D Hough transform, and least squares fitting. The quantitative morphological evaluation method developed may have great value in preliminary screening of DDH in children, formulation of surgical plans, and longitudinal follow-ups after DDH surgery.

Key words: magnetic resonance imaging (MRI), morphological quantification, developmental dysplasia of the hip