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
Diffusion tensor imaging plays an important role in the accurate diagnosis and prognosis of spinal cord diseases. However, because of technical limitations, the imaging sequences used in this technique cannot reveal t...Diffusion tensor imaging plays an important role in the accurate diagnosis and prognosis of spinal cord diseases. However, because of technical limitations, the imaging sequences used in this technique cannot reveal the fine structure of the spinal cord with precision. We used the readout segmentation of long variable echo-trains（RESOLVE） sequence in this cross-sectional study of 45 healthy volunteers aged 20 to 63 years. We found that the RESOLVE sequence significantly increased the resolution of the diffusion images and improved the median signal-to-noise ratio of the middle（C4–6） and lower（C7–T1） cervical segments to the level of the upper cervical segment. In addition, the values of fractional anisotropy and radial diffusivity were significantly higher in white matter than in gray matter. Our study verified that the RESOLVE sequence could improve resolution of diffusion tensor imaging in clinical applications and provide accurate baseline data for the diagnosis and treatment of cervical spinal cord diseases.展开更多
目的:评估基于深度学习重建的半傅立叶采集单次激发快速自旋回波(HASTEDL)序列在肝脏检查中的应用价值。方法:使用3.0T MR对36例患者(男28例,女8例)行上腹部MRI扫描,扫描序列包括单次屏气HASTEDL和多次屏气刀锋伪影校正(BLADE)序列。由...目的:评估基于深度学习重建的半傅立叶采集单次激发快速自旋回波(HASTEDL)序列在肝脏检查中的应用价值。方法:使用3.0T MR对36例患者(男28例,女8例)行上腹部MRI扫描,扫描序列包括单次屏气HASTEDL和多次屏气刀锋伪影校正(BLADE)序列。由两位医师分别对肝脏成像质量(锐利度和伪影)进行五分制主观评分。分别在肝门水平肝脏的肝右叶和肝左叶、病灶显示最大层面及其相应层面同一相位方向的右侧背景区放置感兴趣区,测量两组图像上肝脏的信号强度(SI)及其标准差(SD,作为背景噪声),计算图像的信噪比(SNR)和对比噪声比(CNR)。测量病灶最大径(Dmax),观察和记录图像错层率及病灶检出率。对两组图像上肝右叶和肝左叶内肝实质的SNR、CNR,病灶的SNR、CNR、D值,以及图像错层率、图像质量评分结果分别使用Wilcoxon检验或卡方检验进行组间比较。结果:两位医师对两组图像(HASTEDL和BLADE序列)的主观评分和客观测量数据的一致性均为良好(Kappa和ICC值均大于0.75)。两组之间图像锐利度主观评分的差异无统计学意义(4.62±0.55 vs. 4.27±0.65,P=0.289),HASTE-DL组图像伪影的主观评分显著高于BLADE组(4.78±0.48 vs. 4.14±0.98,P<0.001)。HASTEDL组肝左叶和肝右叶内肝组织的SNR、病灶的SNR和CNR均显著高于BLADE组(P<0.001)。两组之间病灶Dmax的差异无统计学意义(P=0.978)。BLADE组的图像错层率明显高于HASTEDL组(P=0.014)。两组中病灶检出率均为100%。结论:基于深度学习重建的单次屏气HASTE序列能有效提高肝脏T2WI图像质量而不会遗漏病灶,并可显著缩短扫描时间,优化肝脏扫描效率,有较好的临床应用前景。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Diffusion tensor imaging plays an important role in the accurate diagnosis and prognosis of spinal cord diseases. However, because of technical limitations, the imaging sequences used in this technique cannot reveal the fine structure of the spinal cord with precision. We used the readout segmentation of long variable echo-trains（RESOLVE） sequence in this cross-sectional study of 45 healthy volunteers aged 20 to 63 years. We found that the RESOLVE sequence significantly increased the resolution of the diffusion images and improved the median signal-to-noise ratio of the middle（C4–6） and lower（C7–T1） cervical segments to the level of the upper cervical segment. In addition, the values of fractional anisotropy and radial diffusivity were significantly higher in white matter than in gray matter. Our study verified that the RESOLVE sequence could improve resolution of diffusion tensor imaging in clinical applications and provide accurate baseline data for the diagnosis and treatment of cervical spinal cord diseases.
文摘目的:评估基于深度学习重建的半傅立叶采集单次激发快速自旋回波(HASTEDL)序列在肝脏检查中的应用价值。方法:使用3.0T MR对36例患者(男28例,女8例)行上腹部MRI扫描,扫描序列包括单次屏气HASTEDL和多次屏气刀锋伪影校正(BLADE)序列。由两位医师分别对肝脏成像质量(锐利度和伪影)进行五分制主观评分。分别在肝门水平肝脏的肝右叶和肝左叶、病灶显示最大层面及其相应层面同一相位方向的右侧背景区放置感兴趣区,测量两组图像上肝脏的信号强度(SI)及其标准差(SD,作为背景噪声),计算图像的信噪比(SNR)和对比噪声比(CNR)。测量病灶最大径(Dmax),观察和记录图像错层率及病灶检出率。对两组图像上肝右叶和肝左叶内肝实质的SNR、CNR,病灶的SNR、CNR、D值,以及图像错层率、图像质量评分结果分别使用Wilcoxon检验或卡方检验进行组间比较。结果:两位医师对两组图像(HASTEDL和BLADE序列)的主观评分和客观测量数据的一致性均为良好(Kappa和ICC值均大于0.75)。两组之间图像锐利度主观评分的差异无统计学意义(4.62±0.55 vs. 4.27±0.65,P=0.289),HASTE-DL组图像伪影的主观评分显著高于BLADE组(4.78±0.48 vs. 4.14±0.98,P<0.001)。HASTEDL组肝左叶和肝右叶内肝组织的SNR、病灶的SNR和CNR均显著高于BLADE组(P<0.001)。两组之间病灶Dmax的差异无统计学意义(P=0.978)。BLADE组的图像错层率明显高于HASTEDL组(P=0.014)。两组中病灶检出率均为100%。结论:基于深度学习重建的单次屏气HASTE序列能有效提高肝脏T2WI图像质量而不会遗漏病灶,并可显著缩短扫描时间,优化肝脏扫描效率,有较好的临床应用前景。
