Morphological Evaluation Of Avascular Necrotic Femoral Head

Objective:To determine the consistency of morphological measurement parameters of ischemic necrosis femoral head between synthetic CT based on MR and traditional CT.Materials and methods:Two experienced radiologists measured and evaluated the morphological characteristics of the femoral head and the degree of necrosis of the femoral head on the MR-based synthetic CT and traditional CT images of 18 patients(52 ± 10 years old,6 women),including the femoral offset,the diameter of the femoral head,the angle of the neck axis,the maximum sectional area of necrosis and the degree of collapse.The consistency between synthetic CT and CT and between radiologists was analyzed by intra-group correlation coefficient,paired sample t-test and Bland-Altman diagram.Results:The ICCs between sCT and CT range from 0.924 to 0.987;(FO:ICCs 0.960 [0.933 – 0.976];DFH: ICCs 0.987 [0.979 – 0.992];NSA:ICCs 0.924 [0.875 – 0.954];maximum necrotic sectional area: ICCs0.986 [0.977-0.992];collapse degree of femoral head: ICCs 0.983[0.956-0.994];).The paired sample t-test showed that there was a difference between FO and maximum necrotic sectional area CT and sCT(p=0.02,0.003<0.05);DFH,NSA and the degree of collapse of femoral head had no difference between CT and sCT(p>0.05);The inter-reader ICCs range from 0.750 to 0.989,and the intra-reader ICCs range from 0.934 to 0.999;The Bland-Altman diagram shows that CT and sCT have good consistency.Conclusion:The morphological parameters of ischemic necrotic femoral head measured by synthetic CT based on MR and traditional CT have good consistency.