Evaluation Of Clinical Effect Of Optimized Scanning Parameters Gem Energy Spectrum CT In The Measurement Of Bone Mineral Density Of The Lumbar Vertebra

Objective: To investigate the clinical effect of optimized scanning parameters of gem energy spectrum CT in the measurement of bone mineral density(BMD)of human L2、L3 vertebral bodies.Methods: Study group: Select the person who underwent abdominal or lumbar energy spectrum CT(optimized scanning parameters:tube current 260 m A,ball tube rotation rate 0.8 s/r)and QCT simultaneously in Qingdao municipal hospital in April 2019 to October 2019,except for a history of cancer,lumbar injury history,history of lumbar spine surgery,blood disease and other metabolic disease affect bone mineral density of patients,a total of 126 patients,60 patients of men,66 patients of women;Ages 15-92.Energy spectrum CT adopted optimized scanning parameters,and the reconstructed 1.5mm images were transmitted to AW4.6 workstation,and the HAP(lipid)values of L2 and L3 vertebral bodies were measured.The QCT images were transmitted to the Mindways workstation,and the BMD values of L2 and L3 vertebral bodies were measured.Control group: Select the person who underwent abdominal or lumbar energy spectrum CT(default scanning parameters:tube current 375 m A,ball tube rotation rate 0.7s/r)and QCT simultaneously in Qingdao municipal hospital in October 2018-March 2019,except for a history of cancer,lumbar injury history,history of lumbar spine surgery,blood disease and other metabolic disease affect bone mineral density of patients,a total of 57 patients,32 patients of men,25 patients of women;Ages 27-92.Energy spectrum CT adopted default scanning parameters,and the reconstructed 1.5mm images were transmitted to AW4.6 workstation,and the HAP(lipid)values of L2 and L3 vertebral bodies were measured.The QCT images were transmitted to the Mindways workstation,and the BMD values of L2 and L3 vertebral bodies were measured.Statistical software SPSS 25.0 was used to analyze the Pearson correlation between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in the study group and the control group.Statistical software Med Calc was used to test the correlation coefficients of the study group and the control group.Results:(1)The correlation between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in study group of all were r=0.934、 P < 0.001,r=0.930、P <0.001.The correlation between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in study group of men were r=0.893 、P < 0.001,r=0.891 、 P <0.001.The correlation between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in study group of women were r=0.954、P < 0.001,r=0.950、 P <0.001.The HAP(lipid)of L2 and L3 vertebral bodies in the study group had significant correlation with the bone mineral density of QCT.(2)The correlation between HAP(lipid)and QCT bone mineral density in L2 and L3 vertebral bodies in control group of all were r=0.855 、 P < 0.001,r=0.786 、 P <0.001.The correlation between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in control group of men were r=0.837 、P < 0.001,r=0.762 、P <0.001.The correlation between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in control group of women were r=0.841,P < 0.001,r=0.790,P <0.001.The HAP(lipid)of L2 and L3 vertebral bodies in the control group had significant correlation with the bone mineral density of QCT.(3)The correlation between HAP(lipid)and QCT bone mineral density in the subgroups in study group was higher than that in control group(The correlation r=0.934,r=0.930 between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in the subgroups of all in study group were higher than that between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in the subgroups of all in control group r=0.855,r=0.786;the correlation r=0.893、r=0.891 between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in the subgroups of men in study group were higher than that between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in the subgroups of men in control group r=0.837 、r=0.762;the correlation r=0.954 、 r=0.950 between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in the subgroups of women in study group were higher than that between HAP(lipid)and QCT bone mineral density of L2 and L3 vertebral bodies in the subgroups of women in control group r=0.841 、r=0.790).The correlation coefficient comparison difference of L2 and L3 vertebral bodies in the subgroups of all were statistically significant(Z=2.539 、 P=0.011,Z=3.660 、 P<0.001).The correlation coefficient comparison difference of L2 and L3 vertebral bodies in the subgroups of women were statistically significant(Z=2.624 、P=0.009,Z=3.070、P=0.002).The correlation coefficient comparison difference of L2 and L3 vertebral bodies in the subgroups of men were no statistically significant(Z=0.990、P=0.323,Z=1.967、P=0.061).(4)CTDIvol of the study group was 10.30 mGy,and CTDIvol of the control group was15.02 mGy.CTDIvol of the study group was 4.72 mGy lower than that of the control group.Conclusions: Gem energy spectrum CT with optimized scanning parameters is more consistent with QCT.The radiation dose of gem energy spectrum CT with optimized scanning parameters is lower than that with default scanning parameters.