Assessment of liver function using T1 mapping on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid enhanced MRI

Abstract

Objective To investigate the effectiveness of T1 mapping on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA-enhanced) MRI for the assessment of liver function. Methods One hundred and twenty six patients with clinically suspected focal liver lesions and chronic viral hepatitis B underwent MRI were prospectively enrolled. Patients were divided into four subgroups as follows: chronic viral hepatitis B (n=22), liver cirrhosis with Child-Pugh A (n=52), Child-Pugh B (n=41), Child-Pugh C (n=11). Twenty three healthy volunteers with normal liver function were enrolled as control group. Non-enhanced and Gd-EOB-DTPA enhanced MRI of liver were performed in all subjects. Look-Locker sequences with exactly the same scan parameters and geometry position (the level of porta hepatis) were performed pre and post-contrast separately at 5, 10, 15 and 20 minutes after Gd-EOB-DTPA administration. T1 relaxation times and reduction rates of T1 relaxation times [ΔT1(%)] of the liver parenchyma were measured and calculated. One-way ANOVA was used to compare T1 relaxation times and ΔT1(%) for control group, chronic viral hepatitis B group, liver cirrhosis with Child-Pugh A group, Child-Pugh B group, and Child-Pugh C group. ROC curve analysis was performed to compare the diagnostic performance of T1 relaxation times and ΔT1(%) values in discriminating control group+ chronic viral hepatitis B group+ liver cirrhosis with Child-Pugh A group from Child-Pugh B+ C group. Results T1 relaxation times and ΔT1(%) showed significant difference (P<0.05) among control group and different liver function groups. T1 relaxation times and ΔT1(%) of both liver cirrhosis with Child-Pugh B group and Child-Pugh C group were significantly different (P<0.05) in comparison with those of control group, chronic viral hepatitis B group and liver cirrhosis with Child-Pugh A group at all time points. T1 relaxation times of the control group, chronic viral hepatitis B group, liver cirrhosis with Child-Pugh A group and Child-Pugh B group reduced with the scanning time increase, ΔT1(%) raised with the scanning time increase. T1 relaxation times progressively increased from control group to Child-Pugh C group at every time point. ΔT1(%) showed a constant decrease from control group to Child-Pugh C group at all time points. The areas under ROC curve of T1 relaxation time pre and post-contrast at 5, 10, 15 and 20 minutes for assessment of liver function were 0.817, 0.952, 0.950, 0.946, and 0.949 respectively. The areas under ROC curve of ΔT1(%) post-contrast at 5, 10, 15 and 20 minutes for evaluation of liver function were 0.873, 0.876, 0.885, and 0.898, respectively. Conclusion Gd-EOB-DTPA-enhanced T1 mapping MRI is useful for the evaluation of liver function, and helpful for distinguishing patients with moderate and severe liver damage from normal and mild liver damage. Key words: Contrast media; Magnetic resonance imaging; Liver function