定量CT及超声诊断体检人群脂肪肝的比较

目的比较体检中定量CT(QCT)与超声检查对脂肪肝的诊断价值,探讨QCT中肝脏脂肪含量值诊断脂肪肝的阈值。方法筛选2019年10月至2020年10月胸部低剂量CT联合肝脏脂肪定量CT检查的健康体检者500例。统计受检者的BMI值及肝脏超声结果,QCT Pro系统测量肝脏脂肪含量值,常规CT纵隔窗测量计算肝/脾CT值之比,并根据该比值划分脂肪肝组及非脂肪肝组。分析脂肪肝组与非脂肪肝组BMI、肝脏脂肪含量值的差异及BMI肝脏脂肪含量值与肝/脾CT值之比的相关性。ROC曲线评估肝脏脂肪含量值诊断脂肪肝的效能及其阈值。结果体检人群中脂肪肝所占比例为8.6%。两组间BMI值、肝脏脂肪含量值差异有统计学意义(P<0.05),BMI、肝脏脂肪含量值与肝/脾CT值之比均呈负相关(P<0.05)。肝脏脂肪含量值诊断脂肪肝的ROC曲线下面积为0.996,阈值为3.13%(敏感度100%,特异度96.1%),高于超声的敏感度(93.0%)及特异度(81.2%)(P<0.05)。结论QCT诊断脂肪肝的效能高于超声,且能够定量评估肝脏脂肪化程度,使脂肪肝的诊断及后期随访更佳精准化。

Objective To compare the diagnostic value of quantitative CT and ultrasound in fatty liver in physical examination and explore the threshold of liver fat content in quantitative CT to diagnose fatty liver.Methods From October 2019 to October 2020,we screened 500 healthy people who voluntarily performed chest low-dose CT combined with fatty liver quantitative CT examination in the Eastern District of Ningbo Lihuili hospital.The liver fat content was measured by QCT PRO system.The ratio of liver/spleen CT value was calculated by routine CT mediastinal window measurement.According to the ratio,people examined were divided into fatty liver group and none fatty liver group.Independent sample t-test was used to analyze the statistical differences of BMI,liver fat content between fatty liver group and non-fatty liver group.Pearson correlation analysis was used to analyze the correlation of BMI,liver fat content and the ratio of liver/spleen CT value.ROC curve was used to evaluate the value of liver fat content and its threshold value.Results The proportion of fatty liver in the physical examination population in this study was 8.6%(43/500).There were statistical differences in BMI and liver fat content between the two groups(P<0.05).BMI and liver fat content were negatively correlated with the ratio of liver/spleen CT value(P<0.05).The area under ROC curve of diagnosing fatty liver with the fat content of liver was 0.996,and the threshold value was 3.13%(sensitivity 100%,specificity 96.1%),which was higher than the sensitivity(93.0%)and specificity(81.2%)of ultrasound.Conclusion QCT is more effective than ultrasound in diagnosing fatty liver,and it can evaluate the degree of fatty liver quantitatively,which makes the diagnosis and follow-up of fatty liver more accurate.