Power Doppler ultrasonography with time-signal intensity curves in monitoring hepatocellular carcinoma and liver metastases after intralesional therapy.

PURPOSE: Analysis of time-intensity curves allows evaluation of the patterns of lesion enhancement before and after treatment. The aim of this study was to evaluate the diagnostic accuracy of time-intensity curves in monitoring intralesional therapy of focal hepatic lesions. MATERIALS AND METHODS: Twenty patients underwent intralesional therapy with either radiofrequency thermal ablation or percutaneous ethanol injection. Contrast-enhanced power Doppler ultrasound with analysis of time-intensity curves was performed one day before and one day after treatment. Targeted biopsy was then obtained to confirm the imaging findings. RESULTS: Before treatment, all lesions showed time-intensity curves characterised by high peaks of signal intensity and plateaus. Complete tumour necrosis, confirmed by targeted biopsy, was observed in patients showing no intralesional flow signals and time-intensity curves with low peak of signal intensity and absence of plateau after treatment. Biopsy confirmed the presence of residual neoplastic tissue in one patient exhibiting perilesional vascularity, absence of intralesional flow signals, and a time-intensity curve with high peak of signal intensity and plateau. CONCLUSIONS: According to our findings, time-intensity curves characterised by high peak of signal intensity and plateau might reflect the presence of perilesional or intralesional neoplastic tissue and provide important information on the effectiveness of the treatment.