PURPOSE

To investigate whether dynamic contrast -enhanced MRI (DCE-MRI) can distinguish the type of liver nodules in a rat model with N-nitrosodiethylamine- induced cirrhosis.

METHODS

Liver nodules in cirrhosis were induced in 60 male Wistar rats via 0.01 % N-nitrosodiethylamine in the drinking water for 35-100 days. The nodules were divided into three groups: regenerative nodule (RN), dysplastic nodule (DN), and hepatocellular carcinoma (HCC). DCE-MRI was performed, and parameters including transfer constant (K), rate constant (K), extravascular extracellular space volume fraction (V), and initial area under the contrast concentration versus time curve (iAUC) were measured and compared.

RESULTS

The highest K and iAUC values were seen in HCC, followed by DN and RN (all P < 0.05). The area under the receiver operating characteristic curve (AUROC) for DN and HCC were 0.738 and 0.728 for K and iAUC, respectively. The AUROC for HCC were 0.850 and 0.840 for K and iAUC, respectively. Ordinal logistic regression analysis showed that K had a high goodness of fit (0.970, 95 % confidence interval, 13.751-24.958).

CONCLUSION

DCE-MRI is a promising method to differentiate of liver nodules. Elevated K suggested that the nodules may be transformed into HCC.

KEY POINTS

• DCE-MRI is promising for differentiating among RN, DN, and HCC • K and iAUC positively correlated with malignancy degree of liver nodules • Elevated K suggests that the nodules may be transformed into HCC.