Differential Diagnosis of Hepatic Malignant Tumors and Hemangiomas by Using Dynamic Magnetic Resonance Imaging

ABSTRACT

PURPOSE: The purpose of this study is to assess the usefulness of dynamic MR imaging after contrast enhancement with Gd-DTPA in the differential diagnosis of hepatic focal lesions. MATERIALS AND METHODS: The population consists of 22 cases of hepatocellular carcinoma, 44 cases of hemangioma, and five cases of metastasis. Diagnosis of hepatocellular carcinoma was made by surgery, fine needle biopsy, ultrasonography, CT and conventional angiography. Hemangioma was diagnosed on the basis of ultrasonography, CT, conventional spin-echo MRI and clinical data. Diagnosis of metastasis was done by fine needle aspiration biopsy. Dynamic and delayed images were obtained using 1.5T superconductive magnetom after Gd-DTPA(0.1mmol/kg) intravenous injection. Quantitative and qualitative evaluation was done for each lesion. RESULTS: Early contrast enhancement with rapid or gradual washout was noted in 15 lesions of hepatocellular carcinoma(68.2%) ;on the delayed images, no contrast enhancement was noted in 18 lesions(81. 8%). Peripheral contrast enhancement pattern was predominantly(86.4%) observed in hemangiomas during dynamic phase. On the delayed images, homogeneous and persistent contrast enhancement of masses were noted in all hemangiomas. Characteristic centripetal fill-in pattern was observed in 32 lesions of hemangioma (72.7%). Contrast inversion of masses during contrast enhancement study was noted in all hemangiomas, while continuous negative contrast was noted in hepatocellular carcinomas and metastases. CONCLUSION: Dynamic MR imaging after contrast enhancement with Gd-DTPA is an useful method in the differential diagnosis of hepatic focal lesions.