To explore the value of contrast-enhanced ultrasound (CEUS) in therapeutic evaluation of microwave ablation for hepatic alveolar echinococcosis (HAE).

Clinical data of 45 patients with early HAE who received microwave ablation in the Affiliated Hospital of Qinghai University from June 2019 to January 2021 were retrospectively analyzed. Among them, 25 patients were male and 20 female, aged from 17 to 56 years, with a median age of 36 years. The informed consents of all patients were obtained and the local ethical committee approval was received. Before and after microwave ablation, CEUS was performed to observe the changes of lesion size, imaging features and contrast parameters. CEUS was performed at postoperative 3 d and 3, 6 and 12 months to assess the clinical efficacy of microwave ablation. The postoperative lesion diameter were compared by one-way ANOVA. The blood perfusion indexes between two groups were compared by t test.

All 45 lesions from 45 cases were completely ablated by microwave ablation. The complete ablation rate was 100%(45/45) at postoperative 3 d. The effective ablation rates were 100%(45/45), 96%(43/45) and 88%(23/26) at postoperative 3, 6 and 12 months, respectively. Before ablation, no enhancement was observed within the lesions during the arterial phase, portal vein phase and delayed phase. Ring-shaped hyperenhancement was observed at the margins of lesions in 19 cases and 26 cases with homogeneous nodular hyperenhancement. The average preoperative blood perfusion index at the margins of lesions was (100±22) db, significantly higher than (70±27) d in the normal liver tissue (t=8.704, P<0.05). The lesions were completely ablated by microwave ablation, and the blood perfusion index was 0. All patients were followed up for more than 6 months. At postoperative 6 and 12 months, non-homogeneous hyperenhancement was observed at the margins of lesions in 2, 3 cases, respectively, and the blood perfusion index was higher than that of normal liver tissues. The possibility of recurrence was considered. 26 patients were followed up for more than 12 months. The lesion diameter was (4.6±0.6), (3.7±0.5), (3.5±0.4), (2.9±0.4) cm at postoperative 3 d and 3, 6, 12 months, which tended to gradually decrease (F=175.980, P<0.05).

CEUS can dynamically observe the lesion size and arterial blood supply at the margins of lesions in HAE patients, which can accurately evaluate clinical efficacy of microwave ablation and predict the risk of recurrence during follow-up.