Computed tomography appearances of hypervascular hepatic tumors after percutaneous radiofrequency ablation therapy

A retrospective review of the computed tomography (CT) findings of patients with hypervascular liver tumors (26 hepatocellular carcinomas and 2 metastases [1 periampullary carcinoma and 1 neuroendocrine tumor]) who underwent percutaneous ultrasound-guided radiofrequency ablation (RFA) was performed. CT images consisted of nonenhanced and dual-phase contrast-enhanced helical CT images performed on a multidetector CT scan. Findings indicative of adequate tumor ablation on multidetector CT scanwere complete nonenhancement of the treated tumor with or without faint, thin, peripheral rim enhancement. Ablated lesions that showed complete nonenhancement on initial and subsequent follow-up CT examinations either remained stable or became progressively smaller. Thick rim or nodular peripheral enhancement was indicative of tumor residual or recurrence.