Methods Twenty-one patients with 21 untreated liver metastases underwent CEUS with low mechanical index imaging.The characteristic appearances of CEUS in different vascular phases were observed.

• 方法 采用低机械指数实时灰阶谐波反相超声造影技术对21例共21个肝转移癌病灶进行超声造影， 分析研究其造影增强各时相的特征。