ABSTRACT
Objective To evaluate the value of T1 mapping in Gd-EOB-DTPA-enhanced MRI for the assessment of liver function with HBV-related cirrhosis according to the model for end-stage liver disease (MELD) score.Methods 158 patients with HBV-related cirrhosis were included in this prospective study,and divided into MELD score ≤10 (n =103) group and MELD score ＞ 10 (n =55) group.All patients un derwent non-enhanced and Gd-EOB-DTPA enhanced MRI of liver,and T1 mapping was performed using Look-Locker sequences with the same scan parameters and geometry position (the level of porta hepatis) preand post-contrast at 5,10,15 and 20 minutes after Gd-EOB-DTPA administration.T1 relaxation times of the liver were measured and reduction rates of T1 relaxation times (△T1) were calculated.Independent samples t test was performed to compare T1 relaxation times and △T1 between MELD score≤ 10 and MELD score ＞ 10 groups.Receiver operating characteristic curve (ROC) analysis were done to differentiate the diagnostic performance of T1 relaxation times and △T1 between MELD score ≤ 10 and MELD score ＞ 10 groups.Pearson correlation analysis was used to analyse the correction between T1 relaxation times,△T1 and MELD scores.Results T1 relaxation times pre-and post-contrast at 5,10,15 and 20 minutes and △T1 post-contrast at 5,10,15 and 20 minutes of MELD score≤10 group were (889.3 ±91.2) ms,(377.5 ± 55.0) ms,(350.8±61.2)ms,(328.0±69.4)ms,(302.7±73.7)ms,(57.4±5.6)％,(60.4± 6.5) ％,(63.0 ± 7.3) ％ and (65.9 ± 7.8) ％,respectively,and those of MELD score ＞ 10 group were (936.6 ±95.4) ms,(460.2 ±68.5) ms,(457.5 ±94.5) ms,(453.4 ± 116.4) ms,(444.6 ± 134.6) ms,(50.8 ± 5.7) ％,(51.3 ± 7.9) ％,(51.8 ± 10.3) ％ and (52.8 ± 12.2) ％,respectively,and T1 relaxation times and △T1 at all time points were significantly different (P ＜ 0.05) between the two groups.The areas under ROC curve of T1 relaxation time pre-and post-contrast at 5,10,15,20 minutes and △T1 post-contrast at 5,10,15,20 minutes for differentiating MELD score ≤ 10 and MELD score ＞ 10 groups were 0.638,0.824,0.832,0.832,0.830 and 0.795,0.814,0.820,0.825,respectively.The correlation coefficients between T1 relaxation time pre-and post-contrast at 5,10,15,20 minutes,△T1 post-contrast at 5,10,15,20 minutes and MELD scores were 0.256,0.499,0.540,0.538,0.548,-0.412,-0.495,-0.507 and-0.527,respectively.Conclusions T1 mapping on Gd-EOB-DTPA-enhanced MRI is helpful for evaluating liver function with HBV-related cirrhosis.T1 relaxation times post-contrast on different time points were equally accurate as △T1.T1 relaxation times post-contrast and △T1 were superior to T1 relaxation times pre-contrast.
ABSTRACT
Objective To investigate the utilization of liver enhancement in hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI for liver function evaluation.Methods Fifty-five patients who received enhanced MRI with Gd-EOB-DTPA were retrospectively analyzed.Images were obtained before injection and in hepatobiliary phase (5,10,and 20 minutes after Gd-EOB-DTPA injection).The patients were assigned into two subgroups according to individual liver function (n =35 in Group 1:normal liver and Child-Pugh class A; n =20 in Group 2:Child-Pugh class B and C).The relative liver enhancement (RE) was calculated at different time point.The general data (age,sex) and relevant laboratory results were recorded.Independent sample t-test was conducted to compare the RE between two groups at different time point.ROC curve was used to determine the best time point and RE threshold that can reflect the differences between two groups.Univariate analyses was performed to analyze the relationship between RE at the best time point and laboratory results.Multivariate analyses was performed to screen the independent influencing factor for RE at the best time point.Results The differences of RE between two groups were statistically significant at all time points (P ＜ 0.0001).10 minutes was the best time point for detecting the differences of liver function between two groups.When an RE cutoff value (＞ 1.52) was applied,normal or Child-Pugh class A could be predicted with sensitivity of 74.3％ and specificity of 90％.RE at the best time point was significantly related with total serum bilirubin level (TBil),serum albumin level (Alb) and prothrombin time (PT).And TBil was an independent influencing factor.Conclusion RE can be used to evaluate the liver function,and 10 minutes is the best time point that can be used to differentiate patients with normal or mild liver damage from those with moderate or severe liver damage.