RESUMO
Objective To explore the fibrotic stroma characteristics of orthotopic liver cancer in rat and the relationship with MR delayed contrast enhancement.Methods 4 Wistar rats with orthotopic liver cancer underwent conventional triphasal and longer-de-layed contrast-enhancement MR scanning.12 HCC specimens obtained from the four Wistar rats were sliced and stained with HE, picric-sirius red,Verhoeff Van-Gieson elastic fiber,Gordon-Sweets reticular fiber and anti-α-SMA immunohistochemical staining.The relationshp between intratumoral fibrotic stroma and MR delayed phases of the 1 2 tumors were analyzed.Results Collagen fiber was expressed mainly in tumor fibrous septum.Elastic fiber distributed in tumor fibrous septum and the artery wall.Reticular fiber dis-tributed in fibrous septum of the regenerative nodules,portal area and tumor psuedocapsule.Integrated optical density (IOD)value of collagen fiber,elastic fiber and reticular fiber analyzed by Image-pro Plus6.0 were 0.102±0.020,0.063±0.018 and 0.109±0.032, respectively.As a result,the amount of collagen and elastic fibers were statistically different (P<0.01),and so were reticular fibers and elastic fibers (P<0.01).And there was a positive correlation between collagen fiber and MR delayed contrast enhancement (P<0.05).Conclusion MR delayed contrast enhancement of hepatic cancer in rat is closely associated with the collagen fiber,thus this fiber in liver cancer can be evaluated noninvasively by MRI.