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

PURPOSE: Magnetic resonance (MR) images were correlated with results o f fine-needle aspiration (FNA) to determine the role of MR imaging in evaluating hepatic neoplasms treated with percutaneous ethanol ablatio n therapy (PEAT). MATERIALS AND METHODS: Contrast material-enhanced an d unenhanced MR images were obtained in 11 patients with hepatic neopl asms 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 enhanc ement before therapy, four demonstrated persistent enhancement and fou r showed loss of enhancement. Six of these lesions had no viable tumor at FNA. T2-weighted sequences most often showed mixed signal intensit y regardless of T2-weighted imaging appearance before therapy. CONCLUS ION: The MR appearance of PEAT-treated hepatic lesions is not a reliab le indicator of residual or recurrent tumor.