脂肪肝:MRI影像表现及MRI序列选择

Hepatic fatty infiltration:MR findings and choice of MR sequences

目的 :选择评估脂肪肝的MRI序列和认识脂肪肝的MRI影像表现以帮助鉴别诊断。方法 :18例脂肪肝病人进行了肝脏平扫和增强MRI ,采用屏气同、反相位T1加权梯度回波序列、2DFLASH加脂肪抑制T1WI以及HASTET2 WI。结果 :18例肝脂肪变中伴有 7例肝癌 ,2例血管瘤 ,1例囊肿 ,5例肝硬化 ;弥漫型脂肪浸润 6例 ,局灶型脂肪浸润 12例。脂肪肝影像表现 :T1WI同相位表现为稍高或等信号 ,反相位或加压脂T1WI呈低信号 ;T2 WI呈稍高或等信号。部分脂肪肝伴肝内肿块在反相位或加压脂T1WI上可见低信号肿块周边全周或部分环状高信号带。在增强MRI上无明显强化 ,有时见少量小血管进入其内。结论 :同与反相位MRI能较好鉴别诊断脂肪肝。两者互补 ,缺一不可 ,可避免脂肪肝的误诊或漏诊 ,建议对疑有脂肪肝患者行同、反相位T1加权MRI扫描。

Objective:To analyze MR appearance of hepatic fatty infiltration in order to differentiate it with hepatic space occupying lesions and to evaluate MRI sequence as a method of choice for fatty infiltration.Methods:Eighteen patients with hepatic fatty infiltration underwent liver scanning with plain and contrast enhanced MRI.The sequences of MR scanning included in phased and oppose phased and 2D FLASH with fat suppression T 1WI and HASTE T 2WI breath hold MR imaging.Results:Eighteen cases with hepatic fatty infiltration were accompanied with 7 hepatic malignant tumors,2 hepatic heamangiomas,1 hepatic cyst and 5 hepatic cirrhosis.Among which were there 6 with diffuse hepatic fatty infiltration and 12 with focal hepatic fatty infiltration.MRI demonstrated hepatic fatty infiltration slightly high signal intensity or isointensity on in phased and low intensity on oppose phased and 2D FLASH Fat suppression T 1WI as well as slightly high signal intensity on oppose phased T 1WI.Hepatic fatty infiltration was not enhanced on cotrast enhanced T 1WI.Conclusion:The combined use of in phased and oppose phased T 1WI is helpful for diagnosing hepatic fatty infiltration and may provide complementary diagnostic information for hepatic imaging.