A primary study on the phagocytic activity of Kupffer cells with superparamagnetic iron oxide particles enhanced MR imaging in a rat nonalcoholic steatohepatitis model / 中华放射学杂志

ABSTRACT

Objective To investigate the feasibility of using superparamagnetic iron oxide(SPIO)as MRI contrast agent to assess rat nonalcoholic steatohepatitis Kupffer cells(KC)function.Methods Twenty male SD rats were randomly divided into A and B groups,group A(n=10)was the experimental group fed high fat diet,group B(n=10)was the control group fed normal diet After 8 weeks,plain MR and SPIO enhanced MR were performed in all the rats.Blood lipids were measured,and HE and Perl's blue staining in all livers specimen was done.The related results of the staining were analyzed with t test Results Group A TC and TG levels[(6.58±1.25)and(1.53±0.23)mmol/L respectively]were significantly higher than group B[(1.64±0.22)and(0.55±0.14)mmol/L respectively](t=11.716 and 11.588,P＜0.01).Group A and B groups hepatic signal intensity decreased in all sequences after SPIO enhanced,but in group A the level of decline[(34.78±4.51)% and(60.38±3.49)% respectively]was less than group B[(64.96±2.42)% and(81.08±1.66)% respectively]on PDWI and T_1WI,and statistically significant differences(t=-18.451 and-16.240,P＜0.01)were found.In group A the ratio of signal intensity of liver to spleen(1.002±0.141,5.000±0.516,20.004±1.490 and 2.601±0.077 respectively)was more than group B(0.400±0.102,1.500±0.115,0.503±0.105 and-0.300±0.058)before and after contrast enhancement on PDWI,T_2WI,T_2~* WI andT_1WI(t=10.745,19.800,39.168 and 92.785,P＜0.01).Typical histological hepatic lesions of NASH were observed in group A,Perl's staining-positive particles in group A(2.33±0.50)were fewer than in group B(4)(t=-10.000,P＜0.01).Conclusion The high-fat diet induced model of SD rats was close to the human NASH and was easy to establish.Clinical application of SPIO enhanced MR successfully assessed the phagocytic activity of KC in the study,and it suggested that the pathogenesis of NASH was related to the decreased phagocytic activity of KC.