3.0 T MRI扩散加权成像ADC值与SD大鼠肝癌分化程度的相关性研究

3.0 T MR Imaging for Hepatocellular Carcinoma in SD Rats:Correlation with the Histologic Differentiation and Apparent Diffusion Coefficient Value of Diffusion-Weighted

目的探讨3.0 T MRI扩散加权成像(DWI)表观扩散系数(ADC)值与SD大鼠小肝癌分化程度的相关性。方法取SD大鼠80只,注射肝癌诱导试剂,3个月后建立SD大鼠肝癌模型40只,行MRI。常规行T1WI和T2WI定位,DWI采用单次激发自旋回波-回波平面成像(SE-EPI),取b=50 s/mm2和b=100 s/mm2两组,在DWI像上取直径>5 mm高信号结节在相应ADC图上分别测量其ADC值;检查完毕取相应部位结节行HE染色。结果 40个小肝癌病灶中,27个病灶的组织分化类型单一,其中高分化5个,中分化11个,低分化11个,b=50 s/mm2时其对应ADC值分别为(2.31±0.13)×103mm2/s、(2.03±0.18)×103 mm2/s、(1.64±0.24)×103 mm2/s;b=100 s/mm2时其对应ADC值分别为(2.25±0.04)×103mm2/s、(2.11±0.27)×103mm2/s、(1.89±0.20)×103mm2/s;余13个病灶具有中、低分化两种不同的组织分化类型,其中5个病灶主要以低分化为主,另8个病灶主要以中分化为主。不同肝癌等级之间的ADC值比较差异具有统计学意义(P<0.05)。b=50 s/mm2组中,中分化组ADC值高于低分化组(P<0.05),高分化组ADC值均高于低分化组与中分化组(P<0.05);b=100 s/mm2组中,中分化组与高分化组ADC值均高于低分化组(P<0.05),而高、中分化之间差异无统计学意义(P>0.05)。b=50 s/mm2时其相关系数r值为0.863,b=100 s/mm2时其相关系数r值约0.696。结论 DWI ADC值与SD大鼠肝癌的病理分级之间有明显相关性,且b=50 s/mm2时相关性更高。

Objective To establish SD rat models of hepatocellular carcinoma（HCC） and to evaluate the correlation between histopathologic grade and apparent diffusion coefficient. Methods Eighty SD rats were injected HCC mutagens medicine and only 40 HCC SD rat models were established after 3 monthes. The HCC rat models underwent conventional MRI and DWI examination. DWI was obtained with a single shot, echo planar imaging sequence in the axial plane（ b val- ues 50 and 100）. On DWI, the ADC value of the HCC, which larger than 5mm diameter was measured. The lesions were HE stained for histopathologic examination after MRI exanimation. Results Among the 40 HCC lesions, histopathologic results showed high differentiated HCC in 5, moderate differentiated HCC in 11, poor differentiated HCC in 11, moderate and poor differentiated HCC in 13. The mean ADC value of high differentiated HCC were （2.31± 0.13 ） ×103 mm2/s （b = 50 ） and （2.25± 0.04 ） × 103 mm2/s （ b = 100 ） ; the ADC value of moderate differentiated HCC were （ 2.03 ±0. 18 ）× 103 mm2/s （ b = 50） and （2.11± 0.27 ）×103 mm2/s （ b = 100） ; the ADC value of poorly differentiated HCC were （ 1.64± 0.24） × 103mm2/s（ b = 50） and（ 1.89 ± 0.20） × 103mm2/s（ b = 100）. The ADC values（ b = 50） of moderate differentiated HCC were higher than that of poor differentiated HCC （ P 〈 0.05 ）. The ADC values （ b = 50） of high differentiated HCC were higher than that of moderate and poor differentiated HCC （P 〈 0.05 ）. The ADC values （ b = 100） of high and moder- ate differentiated HCC were higher than that of poor differentiated HC （P 〈 0.05 ）, but there was no significant differenceof ADC values（ b = 100） between high and moderate differentiated HCC （P 〉 0.05 ）. The correlation coefficient r value was 0. 863 and 0.696 when b value was 50 and 100. Conclusion The ADC value has significant correlation with histopatho- logical differentiation in HCC SD rat models.