肝硬化和慢性肝炎后小肝癌筛选的有效方法:MR DWI和多期动态增强相结合

Effective screening method of small hepatocellular carcinoma in cirrhosis or chronic hepatitis:combining MR DWI with multiphase dynamic enhanced MRI

目的：探讨MR DWI和多期动态增强诊断肝硬化和慢性肝炎后小肝癌（SHCC）的影像特点和诊断价值。方法：125例肝硬化和慢性肝炎行常规T2WI、T1WI,DWI和4-6期动态增强,所有病例均经手术、介入、定期复查（包括AFP检查）证实。结果：125例肝硬化和慢性肝炎伴再生结节（RN）时DWI未见异常高信号,多期动态增强10例合并动脉期肝脏不均匀强化,静脉期均匀强化,2例合并小动静脉瘘,呈动脉期供血,但静脉期信号不降低。肝发育不良结节（DN）12例14个结节DWI呈等信号或稍高信号,多期动态增强14个结节4个动脉期均匀强化,10个不均匀强化,静脉期及延迟期9个结节信号下降,呈相对低信号,5个结节与肝组织信号一致。28例33个小肝癌结节（SHCC）DWI呈高信号,多期动态增强26个动脉期均匀强化,5个不均匀强化,2个边缘强化,静脉期及延迟期32个信号下降,呈低信号,1个因结节中心合并出血信号未下降,呈等信号,周边信号下降,呈低信号。结论：利用MR DWI和多期动态增强相结合能够比较明确区分RN、DN和SHCC,是肝硬化和慢性肝炎后小肝癌筛选的有效方法,为肝癌的早期发现和治疗提供了明确依据。

Objective To analyze the imaging features of small hepatocellular carcinoma（≤3mm） in cirrhosis or chronic hepatitis by MRI DWI and multiphase dynamic enhanced MRI（3D LAVA）.Method T1WI,T2WI,DWI（SE-EPI,b values=500,600,1 000mm2/s） and 4~6 phase dynamic enhanced（3D LAVA） imaging of the liver were performed on 125 patients with cirrhosis or chronic hepatitis.All of cases were confirmed by postoperative pathology,interventional and regular reexamination（including AFP）.Results The regenerative nodules（RN） in 125 cases with cirrhosis or chronic hepatitis didn＇t show abnormal high signal on MRI DWI imaging, 10 cases with no -iso -hyperintense in arterial phase, but iso -hyperintense in portal venous phase,2 cases with small arteriovenous shunts had arterial blood supply ,hut their intensity were not weaken in portal venous phase. Fourteen dysplastic nodules （DN） intensity of 12 cases were identical or strong slightly with normal liver tissue on MRI DW1,4 of 14 dysplastie nodules were iso - hyperintense and 10 of 14 were no - iso - hyperintense in arterial phase ,9 dysplastie nodules intensity were weaken and 5 of 14 dysplastic nodules intensity were identical with normal liver tissue around in portal venous phase and delayed phases. Thirty -three small hepatocellular carcinoma （SHCC） of 28 cases were strong intensity on MRI DWI,in multiphase dynamic enhanced 26 of 33 malignant nodules were iso -hyperintense,5 of 33 were no -iso- hyperintense ,2 of 33 malignant nodules were border- hyperintense in arterial phase, in portal venous and delayed phases ,32 of 33 were weaken lower intensity and because of center of nodule with hemorrhage 1 of 33 was identical intensity. Conclusion The method of combining DWI with multiphase dynamic enhanced MRI can clearly distinguish among RN, DN and SHCC. It is an effective screening method of small hepatoeellular carcinoma in cirrhosis or chronic hepatitis, and provides definite basis for the early diagnosis and treatment of hepatoeellular careinoma.