Abstract: Abstract Objective: To analyze the correlation with contrast enhanced ultrasonography (CEUS), contrast enhanced CT (CECT) and histopathology through observing the findings of hepatic VX2 tumor in rabbits after RFA on CEUS, CECT and histopathology, and explore the reliability of CEUS in assessing the response of hepatic tumors after RFA. Methods: RFA was applied to rabbit hepatic VX2 tumors. Both CEUS and CECT were performed 1 week after RFA in rabbit models with hepatic VX2 tumor and followed with histopathologic examination. The results of CEUS, CECT and histopathologic examinations were compared. Results: Residual viable tumors were found in 22 models and no residual tumors were seen in 8 models after RFA according to histopathology. The average largest diameter and perpendicular diameter and area of ablation areas were 1.37±0.34 cm, 1.02±0.37 cm and 1.52±0.90 cm on CEUS, respectively. Those of ablation areas were 1.32±0.37 cm, 0.95±0.37 cm, 1.38±0.88 cm and 1.27±0.35 cm, 0.94±0.34 cm, 1.31±0.77 cm on CECT and sample, respectively. According to the results of histopathology, the sensitivity, specificity and accuracy for evaluating therapeutic effect were 90.9％, 75.0％, 86.7％ for CEUS and 86.4％, 87.5％, 86.7％ for CECT, respectively. Conclusion: CEUS is sensitive to capillary vessel. It can accurately discriminate the coagulation necrosis from residual tumors after RFA and offer the reliable foundation for subsequent treatment.

Key words: Ultrasonography, Contrast agent, Radiofrequency ablation, VX2 tumor, Tomography, X-ray computed