肝脏局限性脂肪沉积CT诊断

CT Diagnosis of Local Liver Fat Deposition

目的探讨肝局限性脂肪沉积的发生机制、CT表现特征及临床意义。材料与方法选择2008年1月-2011年8月间,CT检查发现肝局限性脂肪沉积症37例,其中男23例、女14例,平均年龄47.1岁。采用Aquilion16层螺旋CT机,自右膈顶向肝下缘连续平扫及四期增强扫描,37例均符合CT诊断标准。结果肝局限性脂肪沉积症37例病灶分别位于S4段背侧15例、镰状韧带附着部14例、S1段4例、S2段2例、S7段2例;病灶大小为8mm-27mm,平均14.8mm;S4段背侧病灶主要为结节状9例和斑片状5例,镰状韧带附着部病变多为结节状12例;边缘清楚的病灶32例,部分边缘清楚的病灶5例。增强后37例病灶动脉期均未见强化,CT平扫+增强扫描复查,病灶均无明显的变化。局限性脂肪沉积的动脉期能谱曲线向下,而静脉期曲线明显向上,但仍低于正常肝实质曲线。结论肝局限性脂肪沉积症主要与异位静脉引流有关,根据本病的CT表现特征诊断不难,但要注意排除肝内其他类似的占位性病变,定期复查具有决定意义。

Objective To investigate the mechanism of local fatty deposition in the liver,characteristics of CT apparence and clinical significance.Materials and Methods 37 cases which have been reported with the limitations of fat deposition in liver by CT examination from January 2008 to August 2011 were chosen.Among 37 cases,there were 23 males and 14 females,with the average age of 47.1 years old.By using Aquilion 16-slice spiral CT machine,the liver was examined from the top diaphragm to the right lower edge with CT scan and contrast enhanced scan.Results showed 37 cases all met the CT diagnostic criteria.Results Of the 37 cases which have been diagnosed with the limitations of fat deposition in liver,the lesion sites were reported located in the dorsal side of S4（15cases）,the falciform ligament adhere to the liver（14cases）,S1 segment（4cases）,S2 segment（2cases）,and S7 segment（2cases）.The sizes of lesion are from 8mm to 27mm,with an average of 14.8mm.Liver lesions located in the dorsal side of the S4 segment are mainly nodular lesions（9cases） and patchy lesions（5cases）,and the falciform ligament attached to the liver are mostly classified as nodular lesions（12cases）.32 cases have been reported with well-defined lesion edges and the other 5 cases with partially well-defined edges.CT enhancement scan showed no evidence of enhancement in the arterial phase in 37 cases.The spectrum curves of local fat deposition was downward in arterial phase,and in venous phase,the curve significantly upward,but still lower than the curve of normal liver parenchyma.In addition,reexamination using both plain CT scan and contrast enhancement CT scan showed no significant changes to the lesions.Conclusion The limitation of fat deposition in the liver mainly related to the ectopic venous drainage.It not difficult to diagnose this disease if based on characteristics of the CT appearance.However,it is important to rule out other similar space-occupying lesion in liver.Periodic re-examination plays a crucial role in this case.