Transient peritumoral enhancement during dynamic MRI of the liver: Cavernous hemangioma versus hepatocellular carcinoma

Purpose: The purpose of this work was to compare the incidence and pattern of transient peritumoral parenchymal enhancement for cavernous hemangioma and hepatocellular carcinoma during dynamic MRI of the liver. Method: Two hundred seven hemangiomas and 155 hepatocellular carcinomas up to 4 cm in size were retrospectively assessed. The peritumoral enhancement was comparatively analyzed in terms of the shape, extent, signal intensity, and dependence on the size and degree of contrast enhancement of each tumor. Results: For small lesions (<2 cm), hemangiomas (16/141; 11.3%) showed a higher incidence (p = 0.026) of peritumoral enhancement than hepatocellular carcinomas (3/87; 3.5%). For larger lesions (2-4 cm), there was no significant difference (p > 0.05) in the incidence of peritumoral enhancement of hemangiomas (15/66; 22.7%) and hepatocellular carcinomas (15/68; 22.1%). Nineteen (61.3%) of the 31 hemangiomas showed contrast agent filling the entire tumor volume at the phase of peritumoral enhancement. Conclusion: In spite of the limited specificity, for a <2 cm small focal lesion with homogeneous contrast enhancement on early phase dynamic MR images in the liver, peritumoral enhancement could suggest a higher possibility of hemangioma rather than hepatocellular carcinoma.