Peripheral low intensity sign in hepatic hemangioma: diagnostic pitfall in hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI of the liver.

PURPOSE To describe the presence of "peripheral low intensity sign" in hepatic hemangioma in the hepatobiliary phase (HP) of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and to compare the frequency of this sign between hepatic hemangiomas and hepatic metastases. MATERIALS AND METHODS The Institutional Review Board approved this study and waived the requirement for informed consent. Sixty-four patients with 51 hepatic hemangiomas (n = 31 patients) and with 58 hepatic metastases (n = 33 patients) underwent Gd-EOB-DTPA-enhanced MRI. In all hepatic hemangiomas, 41 lesions were the typical type and 10 were the high flow type. HP images were qualitatively evaluated for the frequency of peripheral low intensity sign in hepatic hemangiomas and hepatic metastases using a four-point scale. Statistical evaluations were performed with a Mann-Whitney U-test. RESULTS Peripheral low intensity signs were demonstrated in 24 (47%) of 51 hepatic hemangiomas, while they were seen in 27 (47%) of 58 hepatic metastases. There was no significant difference in the mean visual score of peripheral low intensity sign between all hepatic hemangiomas (0.84 ± 1.03) and hepatic metastases (0.76 ± 0.92). The mean visual score of peripheral low intensity sign in typical hemangiomas (1.02 ± 1.06) was significantly higher than that in high flow hemangiomas (0.10 ± 0.32) (P = 0.008). CONCLUSION Peripheral low intensity sign is not specific for malignant tumors, and can be seen even in hepatic hemangiomas on HP of Gd-EOB-DTPA-enhanced MRI.