目的探讨小儿泌尿系结石CT豪恩斯菲尔德单位(hounsfield unit,HU)在结石成分判断中的应用价值。方法本研究为回顾性研究,以2009年4月至2022年4月在湖南省儿童医院诊断为泌尿系结石符合入选标准的422例患儿为研究对象,基于术后结石成分...目的探讨小儿泌尿系结石CT豪恩斯菲尔德单位(hounsfield unit,HU)在结石成分判断中的应用价值。方法本研究为回顾性研究,以2009年4月至2022年4月在湖南省儿童医院诊断为泌尿系结石符合入选标准的422例患儿为研究对象,基于术后结石成分分析结果将患儿分为4组:草酸钙结石组(n=273)、尿酸结石组(n=89)、鸟粪石组(n=38)、胱氨酸结石组(n=22)。收集所有患儿的尿pH值、结石核心HU值、结石外围HU值、结石平均HU值、HU密度(Hounsfield units density,HUD)等,进行统计学分析。结果4组患儿中结石外围HU值对比,尿酸结石组为399±158、草酸钙结石组为529±223、鸟粪石组为556±312、胱氨酸结石组为566±154,尿酸结石组较草酸钙结石组、鸟粪石组、胱氨酸结石组均小,差异均有统计学意义(P<0.05)。4组中结石平均HU值对比,尿酸结石组为425±166、草酸钙结石组为585±251、鸟粪石组为597±326、胱氨酸结石组为589±155,尿酸结石组较草酸钙结石组、鸟粪石组、胱氨酸结石组均小,差异均有统计学意义(P<0.05)。4组中结石核心HU值对比,尿酸结石组为476±201、草酸钙结石组为697±324、鸟粪石组为681±371,尿酸结石组较草酸钙结石组和鸟粪石组均小,差异均有统计学意义(P<0.05)。4组中HUD对比,草酸钙结石组为65±27、尿酸结石组为39±16、鸟粪石组为54±25、胱氨酸结石组为41±17,草酸钙结石组较尿酸结石组、鸟粪石组、胱氨酸结石组均大,差异均有统计学意义(P<0.05);尿酸结石组较鸟粪石组小,差异有统计学意义(P<0.05)。4组中尿pH值对比,胱氨酸结石组6.5(6.0,7.13),草酸钙结石组6.0(6.0,6.5),尿酸结石组6.0(6.0,6.5);胱氨酸结石组较草酸钙结石组和尿酸结石组均大,差异均有统计学意义(P<0.001)。经计算受试者工作特征曲线下面积(area under curve,AUC),草酸钙结石组与非草酸钙结石组HUD的AUC为0.755,灵敏度为0.722,特异度为0.705,最佳截断值为48;非尿酸结石组与尿酸结石组的核心HU值AUC为0.700,灵敏度为0.607,特异度为0.764,最佳截断值为566;胱氨酸结石组与非胱氨酸结石组中位尿pH值AUC为0.704,灵敏度为0.682,特异度为0.657,最佳截断值为6.25。结论通过CT HU值测量,可以为判定草酸钙结石和尿酸结石成分提供参考;结石核心HU值小于566时,提示尿酸结石;HUD大于等于48时,提示草酸钙结石。展开更多
In order to further study the reliability of macro evaluation indexes,molecular dynamics (MD) was applied to the evaluation of asphalt binder.Micro evaluation indexes (potential energy,surface free energy,solubility p...In order to further study the reliability of macro evaluation indexes,molecular dynamics (MD) was applied to the evaluation of asphalt binder.Micro evaluation indexes (potential energy,surface free energy,solubility parameter and diffusion coefficient) of asphalt binder in different service phases (virgin,modified,aged and rejuvenated) were simulated.Combined with the variation characteristics of asphalt binder macro evaluation indexes (permeability,ductility,viscosity and softening point) in different service phases,the cross-scale correlation of macro-micro evaluation indexes was explored.The results show that the macro and micro evaluation indexes of asphalt binder have different characteristics in different service phases.The essence of the variation in the properties of asphalt binders is the difference in micro composition.In addition,there is a certain correlation between macro and micro evaluation indexes,which can be described by the gray relation theory.The cross-scale correlation of macro-micro evaluation indexes can provide a certain theoretical basis for the development of asphalt binder.展开更多
文摘目的探讨小儿泌尿系结石CT豪恩斯菲尔德单位(hounsfield unit,HU)在结石成分判断中的应用价值。方法本研究为回顾性研究,以2009年4月至2022年4月在湖南省儿童医院诊断为泌尿系结石符合入选标准的422例患儿为研究对象,基于术后结石成分分析结果将患儿分为4组:草酸钙结石组(n=273)、尿酸结石组(n=89)、鸟粪石组(n=38)、胱氨酸结石组(n=22)。收集所有患儿的尿pH值、结石核心HU值、结石外围HU值、结石平均HU值、HU密度(Hounsfield units density,HUD)等,进行统计学分析。结果4组患儿中结石外围HU值对比,尿酸结石组为399±158、草酸钙结石组为529±223、鸟粪石组为556±312、胱氨酸结石组为566±154,尿酸结石组较草酸钙结石组、鸟粪石组、胱氨酸结石组均小,差异均有统计学意义(P<0.05)。4组中结石平均HU值对比,尿酸结石组为425±166、草酸钙结石组为585±251、鸟粪石组为597±326、胱氨酸结石组为589±155,尿酸结石组较草酸钙结石组、鸟粪石组、胱氨酸结石组均小,差异均有统计学意义(P<0.05)。4组中结石核心HU值对比,尿酸结石组为476±201、草酸钙结石组为697±324、鸟粪石组为681±371,尿酸结石组较草酸钙结石组和鸟粪石组均小,差异均有统计学意义(P<0.05)。4组中HUD对比,草酸钙结石组为65±27、尿酸结石组为39±16、鸟粪石组为54±25、胱氨酸结石组为41±17,草酸钙结石组较尿酸结石组、鸟粪石组、胱氨酸结石组均大,差异均有统计学意义(P<0.05);尿酸结石组较鸟粪石组小,差异有统计学意义(P<0.05)。4组中尿pH值对比,胱氨酸结石组6.5(6.0,7.13),草酸钙结石组6.0(6.0,6.5),尿酸结石组6.0(6.0,6.5);胱氨酸结石组较草酸钙结石组和尿酸结石组均大,差异均有统计学意义(P<0.001)。经计算受试者工作特征曲线下面积(area under curve,AUC),草酸钙结石组与非草酸钙结石组HUD的AUC为0.755,灵敏度为0.722,特异度为0.705,最佳截断值为48;非尿酸结石组与尿酸结石组的核心HU值AUC为0.700,灵敏度为0.607,特异度为0.764,最佳截断值为566;胱氨酸结石组与非胱氨酸结石组中位尿pH值AUC为0.704,灵敏度为0.682,特异度为0.657,最佳截断值为6.25。结论通过CT HU值测量,可以为判定草酸钙结石和尿酸结石成分提供参考;结石核心HU值小于566时,提示尿酸结石;HUD大于等于48时,提示草酸钙结石。
基金Funded by the Fundamental Research Funds for the Central Universities (No. 2572021AW10)。
文摘In order to further study the reliability of macro evaluation indexes,molecular dynamics (MD) was applied to the evaluation of asphalt binder.Micro evaluation indexes (potential energy,surface free energy,solubility parameter and diffusion coefficient) of asphalt binder in different service phases (virgin,modified,aged and rejuvenated) were simulated.Combined with the variation characteristics of asphalt binder macro evaluation indexes (permeability,ductility,viscosity and softening point) in different service phases,the cross-scale correlation of macro-micro evaluation indexes was explored.The results show that the macro and micro evaluation indexes of asphalt binder have different characteristics in different service phases.The essence of the variation in the properties of asphalt binders is the difference in micro composition.In addition,there is a certain correlation between macro and micro evaluation indexes,which can be described by the gray relation theory.The cross-scale correlation of macro-micro evaluation indexes can provide a certain theoretical basis for the development of asphalt binder.