Quantitative MRI analysis of normal development of anterior and posterior acetabulum in children / 中国医学影像技术

ABSTRACT

Objective To investigate the normal development of anterior and posterior acetabulum in children through measuring anterior and posterior acetabular indexes with the baseline from the thinnest point of acetabulum to the center of femoral head.Methods MRI data in 165 normal children aged 0-12 years were collected.The baselines were drawn from the center of the femoral head to the thinnest point of acetabulum (method 1) and from the one midpoint of Y cartilage to the contralateral (method 2),then the anterior or posterior bony acetabular index (A/PBAI) and anterior or posterior cartilaginous acetabular indexes (A/PCAI) were measured.The consistency of above parameters measured using two methods and between two observers was observed,and the correlation with parameters-gestational ages was analyzed.Results The consistency of ABAI (ICC=0.832) measured with two methods was good,and the consistency of ACAI (ICC=0.535),PBAI (ICC=0.565) and PCAI (ICC=0.472) was fair.The consistency between two observers was good (all ICC＞0.75).ABAI,ACAI and PBAI were negatively correlated with age (r=-0.762,-0.475,-0.368,all P＜0.001),and PCAI had no correlation with age (r=-0.190,P＜0.005).Before 4 years old,ABAI gradually decreased with age and gradually stabilized after 4 years of age.ACAI and PBAI decreased slightly with aging.PCAI did not change obviously with aging.Conclusion The measuring method of anterior and posterior acetabular indexes with the baseline from the thinnest point of acetabulum to the center of femoral head can accurately evaluate the normal development of anterior and posterior acetabulum in children.