CONTRAST-ENHANCED MR-IMAGING OF HEPATIC-LESIONS TREATED WITH PERCUTANEOUS ETHANOL ABLATION THERAPY

PURPOSE: Magnetic resonance (MR) images were correlated with results of fine-needle aspiration (FNA) to determine the role of MR imaging in evaluating hepatic neoplasms treated with percutaneous ethanol ablation therapy (PEAT). MATERIALS AND METHODS: Contrast material-enhanced and unenhanced MR images were obtained in 11 patients with hepatic neoplasms before PEAT (13 studies) and at intervals after PEAT (25 studies). FNA was performed at each follow-up visit. RESULTS: After PEAT, the MR appearance of the lesions was extremely variable. Also, the signal characteristics of most lesions did not change significantly with any sequence over time. Of eight lesions that demonstrated contrast enhancement before therapy, four demonstrated persistent enhancement and four showed loss of enhancement. Six of these lesions had no viable tumor at FNA. T2-weighted sequences most often showed mixed signal intensity regardless of T2-weighted imaging appearance before therapy. CONCLUSION: The MR appearance of PEAT-treated hepatic lesions is not a reliable indicator of residual or recurrent tumor.