Abstract:

Abstract:Objective
To observe the growth characteristics and multi-time dynamic contrast-enhanced MR(DCE-MR) findings of rabbit VX2 liver tumor on MR imaging，and to provide a reliable basis for the values of MR in assessment of non-surgical treatment effect of rabbit VX2 liver tumor.Methods 10 rabbit VX2 liver tumor models were established by liver tissue embedding through laparotomy under direct vision  and DCE-MRI scaning was performed at the 2nd,3rd,4th and 5th week after establishment.The tumor volume (V) and tumor growth rate（TGR)  were calculated at different time points and the signal characteristics were analyzed on MR imaging;then all the rabbits were excuted and   HE staining were performed to observe the cancer cells in different places with microscope.Results The TGR at the  3rd week after establishment （404.16%±114.64%） was significantly higher than that at the  4th week （223.49%±65.90%）（t=3.417，P<0.05）.The tumors with well-boundary were rim-like enhanced significantly and the central parts were not enhanced on DCE-MR imaging,and the parts between the edge and centre of tumors were heterogeneously mild enhanced.The HE staining results showed that 6 cases of tumor were squamous cell carcinoma and the cells were distributed densely in the edge,the cancer cells and necrosis were distributed equally in the parts between the edge and centre of tumors and the centre of tumors were necrosis parts.Conclusion The rabbit VX2 liver tumor grows rapidly at the 3rd week after establishment,and its histological features can be better reflected by DCE-MRI.

Key words: VX2, liver neoplasms, magnetic resonance imaging, dynamic contrast-enhanced MR imaging