Small hepatocelluler carcinoma and dysplastic nodules in cirrhotic livers: Differantiation with dynamic MR imaging

To evaluate the usefulness of spin-echo T2 and T1-weighted images and contrast-enhanced dynamic gradient-echo images in differentiating between hepatocellular carcinoma and dysplastic nodules in cirrhotic livers. Method: Thirty-eight patients with liver cirrhosis underwent spin-echo T2 and T1-weighted and contrast-enhanced dynamic gradient-echo imaging. 16 small hepatocellular carcinomas (< 3 cm) in 16 patients and 12 dysplastic nodules (> 1 cm) in 12 patients were included in this study. Spin-echo sequences and dynamic examination were compared for characterisation of liver lesions. Results: On combined SE T2 and T1-weighted images and dynamic MR images, the most common appearances were hyperintensity on T2-weighted images (63%), hyperintensity on T1-weighted images (50%) and hypervascularity (88%) for hepatocellular carcinomas. All of the dysplastic nodules were isointense on T2-weighted images and except one, all dysplastic nodules enhanced similar to the liver parenchyma. Conclusion: In the differential diagnosis of focal lesions in cirrhotic liver, contrast enhancement features are as diagnostic as the signal intensity of the lesions on spin-echo sequences. Hyperintensity on T2-weighted images and hypervascularity on dynamic contrast- enhanced MR imaging are statistically significant features of HCCs developing in cirrhotic livers.