Real-time Monitoring of Contrast-enhanced Ultrasound for Radio Frequency Ablation

BACKGROUND: This study compared the realtime monitoring effects of conventional ultrasound and contrast-enhanced ultrasound (CEUS) on evaluating radio frequency ablation (RFA) in a living swine liver model. METHODOLOGY: Liver RFA was performed on 10 young swine. Conventional ultrasound and CEUS were performed immediately. After the animals were sacrificed, ablation lesions were removed to histopathologically examine the range of the lesions. Ablation completeness based on three methods were compared using histopathology as the gold standard. RESULTS: Forty-three ablation lesions were produced in the animals. The horizontal diameter, vertical diameter and ablation lesion area based on conventional ultrasound were all significantly smaller than those based on the gross sample, but no significant differences existed between the results of the CEUS and the gross sample. Histopathology showed that 30 lesions were incompletely ablated and 13 were completely ablated, while CEUS showed that 28 lesions were incompletely ablated and 15 were completely ablated. Compared with histopathology, CEUS had an accuracy of 81.4%, a sensitivity of 83.3%, and a specificity of 76.9%. No significant difference in ablation completeness judgment between CEUS and histopathology was observed. CONCLUSION: CEUS provides a real-time radiological foundation for evaluating RFA lesion ranges and completeness in a living swine liver model.