Hepatic Enhancement on Gd-BOPTA-enhanced MR Imaging: Comparison between Cirrhotic and Normal Livers

ABSTRACT

PURPOSE: To compare the enhancement features of hepatic parenchyma between cirrhotic and normal liver, using Gd-BOPTA-enhanced delayed MR imaging. MATERIALS AND METHODS: The 60 patients (35 with cirrhotic and 25 with normal liver) included in our study underwent Gd-BOPTA-enhanced MR imaging using a 1.5T system with a phase-array multicoil. In all cases, T1-weighted in-phase and opposed-phase gradient-echo MR imaging was performed before and 60 minutes after intravenous administration of a bolus of Gd-BOPTA. All images were quantitatively analysed by comparing the signal-to-noise ratio (SNR) and signal enhancement (SE) of cirrhotic and normal liver before and after contrast enhancement, and in cirrhotic patients, SNR and SE were also compared in terms of the Child-Pugh classification. For qualitative analysis, the hepatic enhancement patterns of cirrhotic and normal liver were classified as homogeneous or heterogeneous according to the consensual findings of two radiologists. RESULTS: At contrast-enhanced imaging, both cirrhotic (p<0.001) and normal liver (p<0.001) showed substantially increased SNR relative to unenhanced images, and the SNR of cirrhotic liver was significantly lower than that of normal livers at both in-phase (p<0.001) and opposed-phase (p<0.001) imaging. The SE of cirrhotic liver was significantly lower than that of normal liver (in-phase: p=0.002; opposed phase: p=0.011). Both Child-Pugh class A (p<0.001) and B (p<0.001) cirrhotic liver showed a substantial increase in SNR at contrast-enhanced imaging relative to unenhanced imaging and the SNR of Child-Pugh class A was significantly higher than that of Child-Pugh class B at both in-phase (p<0.001) and opposed-phase (p=0.022) imaging. In addition, the SE of class A was significantly higher than that of class B at in-phase imaging (p=0.004). Cirrhotic liver showed heterogeneous enhancement in 20 of 35 patients (57%), whereas normal liver showed homogeneous enhancement in all patients. CONCLUSION: At Gd-BOPTA-enhanced delayed MR imaging, cirrhotic liver showed less enhancement than normal liver. In cirrhotic patients, hepatic enhancement and hepatic function decreased in tandem. Gd-BOPTAenhanced delayed MR imaging may be useful for evaluating the functional reserve of the liver.