基于CT值及三维重建的股骨骨段骨密度值快速求解研究

A quick solution for segmental femur bone density based on CT value and three-dimensional reconstruction

目的探讨基于CT值及三维重建的股骨、股骨头、股骨颈、股骨髁骨密度值快速求解方法。方法采用12侧成人尸体下肢标本为实验材料,实验分成实验组及真实测量组。实验组按0.5mm层距进行股骨CT扫描、三维重建、读取像素CT值数据;将股骨三维模型骨段分为股骨头、股骨颈、股骨干及股骨髁,分别读取股骨及各段三维模型的像素CT值数据。真实测量组经标本制作、分别测量整体股骨及各段的质量及体积,计算骨密度值。实验组三维模型像素CT值均值与真实测量组骨密度值进行相关分析,获得像素CT值均值与骨密度值的数学函数关系,通过函数计算出来的骨密度值与真实测量组进行单因素方差分析。结果 (1)骨密度真实测量值与CT值均值的相关分析:整体股骨y=0.2535x0.2901,R2=0.9464;股骨头y=0.027x0.6085,R2=0.915;股骨颈y=0.0324x0.5849,R2=0.862;股骨髁y=0.0245x0.614,R2=0.8492。(2)骨密度计算值与真实测量值的单因素方差分析:整体股骨P=0.987;股骨头P=0.984;股骨颈P=0.962;股骨髁P=0.971。结论 (1)股骨三维重建后通过像素CT值均值可以快速求解骨密度值;(2)骨段进行股骨骨密度值测量结果精确,质量控制良好;(3)为临床快速骨密度值求解提供实践手段及理论依据。

Objective To investigate a fast solution method for bone density of femur, the femoral head, femoral neck and femoral condyle based on CT value and three-dimensional reconstruction. Methods Twelve sides of lower extremity specimens of adult corpses were used for our experiments. Experiment were divided into experimental group and measurement group. The femurs of experimental group was treated with 0. 5 mm thin-slice CT scan, three-dimensional reconstruction, harvest the CT value of pixels. The femoral three-dimensional models were divided into four segments of femoral head, femoral neck, femoral shaft and femoral condyle. The CT value data of femoral three-dimensional models and segments were harvested respectively. Measurement group was treated to prepare specimens, measure mass and the volume of entire femur and segments, then calculate the bone density. The mean CT value of three-dimensional model of experimental group and the bone density of measurement group were treated with correlation analysis to obtain mathematical functions between bone density and the mean CT value. The calculated bone density values and that of measurement group were treated with one-factor analysis of variance. Results （ 1 ） Correlation analysis between bone density values of measurement group and the mean CT value： femur y = 0. 2535 x^0.2901, R^2 = 0. 9464 ; femur head y = 0. 027x^0.6085, R^2 = 0. 915 ; femur neck y = 0. 0324x^0. 5849,R^2= 0. 862 ; femoral condyle y = 0.0245x^0.614, R^2 = 0. 8492. （2）One-factor analysis of variance between calculated bone density values and that of measurement group ： femur P = 0. 987 ; femur head P = 0. 984 ; femur neck P = 0. 962 ; femoral condyle P = 0. 971. Conclusions （ 1 ） The bone density of femur could be quickly harvested through the mean CT value after three-dimensional reconstruction; （2） Segmental femur bone density measurement could obtain a more precise result and better quality control;（3 ）To provide a practical method and theoretical tbundation of fast solutionmethod of bone density for clinical orthopedics.