Background:The accurate measurement of the femoral anteversion (FA) angle is always a topic of much debate in the orthopedic surgery and radiology research.We aimed to explore a new FA measurement method to acquire accurate results without radiation damage using piglet model.Methods:A total of thirty piglets were assigned to two groups based on the age.Bilateral femora were imaged with 3.0-T magnetic resonance (MR) and 64-slice computed tomography (CT) examinations on all piglets.FA was measured on MR-three-dimensional (3D) postprocessing software with a four-step method:initial validation of the femoral condylar axis,validation of the condylar plane,validation of the femoral neck axis,and line-plane angle measurement of FA.After MR and CT examinations,all piglets were sacrificed and their degree of FA was measured using their excised,dried femora.MR,CT,and dried-femur measurement results were analyzed statistically;MR and CT measurements were compared for accuracy against each other and against the gold standard dried femur measurement.Results:In both groups,the mean FA value measured by MR was lower than that measured by CT.A statistically significant difference was observed between CT-and dried-femur measurements but not between MR-and dried-femur measurements.A higher correlation (0.783 vs.0.408) and a higher consistency (0.863 vs.0.578) with dried-femur measurement results were seen for MR measurements than CT measurements in the 1-week age group.However,in the 8-week age group,similar correlations (0.707 vs.0.669) and consistencies (0.864 vs.0.821) were observed.Conclusions:Noninvasive MR-3D-Cube reconstruction was able to accurately measure FA in piglets.Particularly in the 1-week age group with a larger proportion of cartilaginous structures,the correlation and consistency between MR-and dried-femur measurement results were higher than those between CT-and dried-femur measurements,suggesting that MR may be a new useful examination tool for FA-related diseases in children.