Gd-EOB-DTPA增强MRI对慢性乙型病毒性肝炎肝纤维化分期的评估价值

Value of Gd-EOB-DTPA-enhanced MRI in the evaluation to liver fibrosis stage of chronic HBV

目的:探讨钆塞酸二钠(Gd-EOB-DTPA)增强MRI对各期肝纤维化的评估价值。方法:共纳入79例慢性乙型病毒性肝炎(乙肝)患者,均取得纤维化分期的病理结果,其中肝纤维化S1期19例(S1组)、S2期21例(S2组)、S3期23例(S3组)、S4期16例(S4组)。收集20例无肝炎病史者(S0期)作为对照组。MRI检查采用Look-Locker序列并于Gd-EOB-DTPA增强扫描前及肝胆期采集标准T_(1) mapping图像,测量肝组织肝胆期增强扫描后的T_(1)值(T_(1)post),同时计算肝细胞分数(HeF)、摄取系数(KHeP)、肝胆期T_(1)弛豫时间减低率(ΔT_(1))。采用单因素方差分析比较肝纤维化各期的T_(1)post、HeF、KHeP、ΔT_(1),并使用ROC曲线分析T_(1)post、HeF、KHeP、ΔT_(1)对肝纤维化≥S2期、≥S3期的诊断效能。采用Spearman相关分析评价上述参数与肝纤维化分期的相关性,采用组内相关系数(ICC)评价2名医师测量各参数的一致性。结果:S0、S1、S2、S3、S4期组间T_(1)post、HeF、KHeP和ΔT_(1)值比较差异均有统计学意义(均P<0.05)。S0组T_(1)post、HeF、KHeP、ΔT_(1)分别为(241.94±45.51)ms、(81.78±5.32)%、(13.07±2.57)min^(-1)、(67.24±7.73)%,S1组为(273.21±38.91)ms、(80.27±4.67)%、(11.28±1.95)min^(-1)、(63.45±4.13)%,S2组为(296.51±63.17)ms、(75.85±5.90)%、(10.59±2.64)min^(-1)、(61.54±3.07)%,S3组为(371.48±157.23)ms、(68.80±19.12)%、(8.75±3.90)min^(-1)、(43.61±6.72)%,S4组为(474.36±79.59)ms、(53.61±11.83)%、(3.51±1.81)min^(-1)、(35.12±4.39)%。2名医师对T_(1)post、HeF、KHeP、ΔT_(1)的测量均有较好的一致性(ICC=0.985、0.993、0.987、0.638,均P<0.001)。T_(1)post与肝纤维化呈正相关(r=0.700,P<0.001),HeF、KHeP、ΔT_(1)与肝纤维化均呈负相关(r=-0.634、-0.658、-0.847,均P<0.001)。结论:Gd-EOB-DTPA增强MRI的HeF、T_(1)post、KHeP、ΔT_(1)对乙肝各期肝纤维化的评估有一定价值。

Objective:To investigate the diagnostic value of hepatocyte fraction(HeF)in Gd-EOB-DTPA-enhanced MRI for liver fibrosis stage of chronic HBV.Methods:A total of 79 patients with chronic HBV and liver fibrosis were classified into 4 groups as follows:19 cases in liver fibrosis stage 1(S1),21 cases in stage 2(S2),23 cases in stage 3(S3),16 cases in stage 4(S4).And 20 patients without hepatitis were collected as the control group(S0).Look-Locker sequence was used in MRI scanning.Standard T_(1) mapping images were obtained before Gd-EOB-DTPA enhancement and in hepatobiliary phase.T_(1) relaxation time of the liver parenchyma in hepatobiliary phase(T_(1)post)was measured,and HeF,KHeP and reduction rate of T_(1) relaxation time(ΔT_(1))were calculated.One way ANOVA was used to compare T_(1)post,HeF,KHeP and ΔT_(1) among the 5 groups,and then ROC curve analysis was performed to evaluate the diagnostic values of T_(1)post,HeF,KHeP and ΔT_(1) to liver fibrosis stages(≥S2 and≥S3).Spearman correlation analysis was utilized to assess the correlation between the parameters and liver fibrosis stage.Intraclass correlation coefficient(ICC)was used to estimate the consistency of the parameters between the two observers.Results:There were statistically significant differences in T_(1)post,HeF,KHeP and ΔT_(1) among the five groups(all P<0.05).T_(1)post,HeF,KHeP and ΔT_(1) were(241.94±45.51)ms,(81.78±5.32)%,(13.07±2.57)min^(-1),(67.24±7.73)%each in S0 group;(273.21±38.91)ms,(80.27±4.67)%,(11.28±1.95)min^(-1),(63.45±4.13)%each in S1 group;(296.51±63.17)ms,(75.85±5.90)%,(10.59±2.64)min^(-1),(61.54±3.07)%each in S2 group;(371.48±157.23)ms,(68.8±19.12)%,(8.75±3.90)min^(-1),(43.61±6.72)%each in S3 group;(474.36±79.59)ms,(53.61±11.83)%,(3.51±1.81)min^(-1),(35.12±4.39)%each in S4 group respectively.There were good agreements between the two observers on T_(1)post,HeF,KHeP and ΔT_(1) measurements(ICC=0.985,0.993,0.987,0.638,all P<0.001).T_(1)post was positively correlated with liver fibrosis(r=0.700,P<0.001).HeF,KHeP and ΔT_(1) were negatively correlated with liver fibrosis(r=-0.634,-0.658,-0.847,all P<0.001).Conclusion:HeF in Gd-EOB-DTPA-enhanced MRI has good value in the assessment of liver fibrosis.