| Objective:This study aims to create a three-dimensional calcaneus model based on multi-slice spiral CT three-dimensional volume display technology,measure its related anatomical data,compare the differences between different genders,screen out the indicators with significant differences,establish the judgment function equation for inferring gender by Fisher discriminant analysis,and verify the accuracy of the function equation by leaving a cross.Also,it is designed to investigate the feasibility and accuracy of calcaneal CT three-dimensional imaging in inferring adult gender.Methods:Data of 320 patients aged 18-80 years old who underwent CT scan of foot and ankle in the Department of radiology of Qingdao Municipal Hospital from June 1,2019 to February 1,2020 were collected.There were 160 males with an average age of 44.45±12.47 years and 160 females with an average age of 43.50±13.83 years.The total length of calcaneus,the highest calcaneus,the widest calcaneus,the posterior calcaneus width,Bohler’s angle and Gissane’s angle were measured and statistically analyzed.Results:The mean values of the five length indexes(X1,X2,X3,X4,X5)in male group were 77.82±4.31 mm,28.06±2.30 mm,44.60±2.88 mm,43.38±3.00 mm,32.63±2.11 mm respectively;in female group were 72.06±3.14 mm,25.04±1.87 mm,40.84±2.16 mm,40.20±2.53 mm,29.38±2.11 mm respectively The mean values of Bohler’s angle and Gissane’s angle were 32.92±5.38 degrees and 118.32±5.88 degrees in male group and 35.50±4.87 degrees and 118.82±5.09 degrees in female group,respectively.The mean value of Bohler’s angle in male was less than that in female,and there was significant difference between the two sexes(P=0.027),but there was no significant difference in Gissane’s angle between the two sexes(P>0.05).The accuracy of gender determination of single measurement index is 70%-82.5%,and the highest is the total length of calcaneus;the comprehensive accuracy of gender determination equation of full length index is 80-95%,and the comprehensive accuracy is 87.5%;the accuracy of stepwise inference function equation is 80-95%,and the highest is the female.The accuracy rate of gender determination was 80%-92.5%,and the highest accuracy rate of female classification was 92.5%.Conclusion:The measurement software of CT post-processing workstation can realize the quantitative analysis of image meridian,angle and so on,with high accuracy and repeatable operation.Calcaneus can be used as a choice to infer gender in forensic medicine,especially when there is no more accurate bone selection. |
