AIM:To establish and validate a simple quantitative assessment method for nonalcoholic fatty liver disease(NAFLD)based on a combination of the ultrasound hepatic/renal ratio and hepatic attenuation rate.METHODS:A tota...AIM:To establish and validate a simple quantitative assessment method for nonalcoholic fatty liver disease(NAFLD)based on a combination of the ultrasound hepatic/renal ratio and hepatic attenuation rate.METHODS:A total of 170 subjects were enrolled in this study.All subjects were examined by ultrasound and 1H-magnetic resonance spectroscopy(1H-MRS)on the same day.The ultrasound hepatic/renal echointensity ratio and ultrasound hepatic echo-intensity attenuation rate were obtained from ordinary ultrasound images using the MATLAB program.RESULTS:Correlation analysis revealed that the ultrasound hepatic/renal ratio and hepatic echo-intensity attenuation rate were significantly correlated with 1HMRS liver fat content(ultrasound hepatic/renal ratio:r=0.952,P=0.000;hepatic echo-intensity attenuation r=0.850,P=0.000).The equation for predictingliver fat content by ultrasound(quantitative ultrasound model)is:liver fat content(%)=61.519×ultrasound hepatic/renal ratio+167.701×hepatic echo-intensity attenuation rate-26.736.Spearman correlation analysis revealed that the liver fat content ratio of the quantitative ultrasound model was positively correlated with serum alanine aminotransferase,aspartate aminotransferase,and triglyceride,but negatively correlated with high density lipoprotein cholesterol.Receiver operating characteristic curve analysis revealed that the optimal point for diagnosing fatty liver was 9.15%in the quantitative ultrasound model.Furthermore,in the quantitative ultrasound model,fatty liver diagnostic sensitivity and specificity were 94.7%and 100.0%,respectively,showing that the quantitative ultrasound model was better than conventional ultrasound methods or the combined ultrasound hepatic/renal ratio and hepatic echo-intensity attenuation rate.If the 1H-MRS liver fat content had a value<15%,the sensitivity and specificity of the ultrasound quantitative model would be 81.4%and 100%,which still shows that using the model is better than the other methods.CONCLUSION:The quantitative ultrasound model is a simple,low-cost,and sensitive tool that can accurately assess hepatic fat content in clinical practice.It provides an easy and effective parameter for the early diagnosis of mild hepatic steatosis and evaluation of the efficacy of NAFLD treatment.展开更多
为更好地发挥星地闪电探测资料在中尺度对流系统中的监测预警应用潜力,本文以2018年6月27日山东地区的一次中尺度对流系统为例,利用云顶温度、云顶降温率、雷达等资料与FY-4A闪电成像仪LMI(Lightning Mapping Imager)、ADTD(Advanced TO...为更好地发挥星地闪电探测资料在中尺度对流系统中的监测预警应用潜力,本文以2018年6月27日山东地区的一次中尺度对流系统为例,利用云顶温度、云顶降温率、雷达等资料与FY-4A闪电成像仪LMI(Lightning Mapping Imager)、ADTD(Advanced TOA and Direction system)闪电定位系统星地闪电探测资料,分析了星地闪电数据在中尺度对流系统中闪电分布特征及其与对流演变的关系,结果表明:星地探测闪电一致性较好,LMI相对位于对流云前方,星地闪电与降水区域吻合度较高。在系统发展初期,LMI超前于ADTD探测到闪电,且位于回波中心和前侧,回波垂直方向呈现出向前倾斜特征,这对于判识对流移动和演变趋势有较好的指示作用,在预报业务中可采用LMI的位置来辅助制作强对流落区预报。在成熟阶段,星地闪电频次出现跃增,正地闪比例较高,该时段山东多地发生冰雹灾害,LMI多出现在对流系统移动方向前方的弱回波或无回波区内,ADTD则更接近回波中心位置。合并阶段,部分LMI位于前方强回波区后部,与强回波区相对应。展开更多
文摘AIM:To establish and validate a simple quantitative assessment method for nonalcoholic fatty liver disease(NAFLD)based on a combination of the ultrasound hepatic/renal ratio and hepatic attenuation rate.METHODS:A total of 170 subjects were enrolled in this study.All subjects were examined by ultrasound and 1H-magnetic resonance spectroscopy(1H-MRS)on the same day.The ultrasound hepatic/renal echointensity ratio and ultrasound hepatic echo-intensity attenuation rate were obtained from ordinary ultrasound images using the MATLAB program.RESULTS:Correlation analysis revealed that the ultrasound hepatic/renal ratio and hepatic echo-intensity attenuation rate were significantly correlated with 1HMRS liver fat content(ultrasound hepatic/renal ratio:r=0.952,P=0.000;hepatic echo-intensity attenuation r=0.850,P=0.000).The equation for predictingliver fat content by ultrasound(quantitative ultrasound model)is:liver fat content(%)=61.519×ultrasound hepatic/renal ratio+167.701×hepatic echo-intensity attenuation rate-26.736.Spearman correlation analysis revealed that the liver fat content ratio of the quantitative ultrasound model was positively correlated with serum alanine aminotransferase,aspartate aminotransferase,and triglyceride,but negatively correlated with high density lipoprotein cholesterol.Receiver operating characteristic curve analysis revealed that the optimal point for diagnosing fatty liver was 9.15%in the quantitative ultrasound model.Furthermore,in the quantitative ultrasound model,fatty liver diagnostic sensitivity and specificity were 94.7%and 100.0%,respectively,showing that the quantitative ultrasound model was better than conventional ultrasound methods or the combined ultrasound hepatic/renal ratio and hepatic echo-intensity attenuation rate.If the 1H-MRS liver fat content had a value<15%,the sensitivity and specificity of the ultrasound quantitative model would be 81.4%and 100%,which still shows that using the model is better than the other methods.CONCLUSION:The quantitative ultrasound model is a simple,low-cost,and sensitive tool that can accurately assess hepatic fat content in clinical practice.It provides an easy and effective parameter for the early diagnosis of mild hepatic steatosis and evaluation of the efficacy of NAFLD treatment.
文摘为更好地发挥星地闪电探测资料在中尺度对流系统中的监测预警应用潜力,本文以2018年6月27日山东地区的一次中尺度对流系统为例,利用云顶温度、云顶降温率、雷达等资料与FY-4A闪电成像仪LMI(Lightning Mapping Imager)、ADTD(Advanced TOA and Direction system)闪电定位系统星地闪电探测资料,分析了星地闪电数据在中尺度对流系统中闪电分布特征及其与对流演变的关系,结果表明:星地探测闪电一致性较好,LMI相对位于对流云前方,星地闪电与降水区域吻合度较高。在系统发展初期,LMI超前于ADTD探测到闪电,且位于回波中心和前侧,回波垂直方向呈现出向前倾斜特征,这对于判识对流移动和演变趋势有较好的指示作用,在预报业务中可采用LMI的位置来辅助制作强对流落区预报。在成熟阶段,星地闪电频次出现跃增,正地闪比例较高,该时段山东多地发生冰雹灾害,LMI多出现在对流系统移动方向前方的弱回波或无回波区内,ADTD则更接近回波中心位置。合并阶段,部分LMI位于前方强回波区后部,与强回波区相对应。
