目的　分析原发性肝细胞癌高强度聚焦超声 (highintensityfocusedultrasound ,HIFU )治疗后的MRI表现。 方法　 2 1例经病理或临床诊断的原发性肝细胞癌患者在HIFU治疗前、后行腹部的轴位T1WI ,轴位T2WI ,冠状位SPIR ,以及GD DTPA增强后T1WI的轴位、FFE序列的冠状位扫描。在MRI图像上观察肿瘤在HIFU治疗前、后的大小及信号改变。结果　HIFU治疗 2 9个癌灶 ,其中 2 4个缩小 ( 82 .76% ) ,5个增大 ( 17.2 4% ) ;在T1WI增强上 2 6个 ( 89.66% )出现无信号增强区 ,12个癌灶无增强区周围见环状强化 ,7个强化环内见低信号环 (T1WI、T2WI、SPIR)。无强化区大多在T1WI表现为低信号或高信号 ,T2WI为低、等信号或高信号 ,SPIR序列为低、等信号或高信号 ,FE序列为低信号。结论　HIFU治疗后 ,肝癌瘤灶内可出现多种MR信号改变 ,MR成像应成为肝癌HIFU治疗效果评估的一种无创而有效的方法 Objective To analyze the MRI findings of high intensity focused ultrasound (HIFU) treatment of primary hepatocellular carcinoma (HCC). Methods Twenty-one patients with pathologically or clinically diagnosed primary hepatocellular carcinoma before and after HIFU treatment underwent axial T1WI, axial T2WI, and coronal SPIR, and axial T1WI and FFE sequences after enhanced GD DTPA Coronal scan. The tumor size and signal change before and after HIFU treatment were observed on MRI images. Results HIFU treatment was performed in 29 cancerous lesions, of which 24 were narrowed (82.76%) and 5 were enlarged (17.2 4%). There were no signal enhancement regions in 26 (89.66%) of T1WI enhancement and 12 See no enhancement around the ring enhancement of the ring around the ring, seven enhanced ring see the low signal loop (T1WI, T2WI, SPIR). Most of the areas without enhancement showed low signal or high signal at T1WI, T2WI low signal and high signal, SPIR sequence was low, equal signal or high signal, and FE sequence was low signal. Conclusion After treatment with HIFU, many MR signals may appear in the tumor of liver cancer. MR imaging should be a noninvasive and effective method to evaluate the therapeutic effect of HIFU