Brain Tumor Enhancement In Magnetic Resonanc Imaging At 7 Tesla Intraindividual Comparison Of Two New Contrast Agents With A Conventional Contrast Agent Magnevist In A Mouse Brain Glioma Model

Objective:The aim of our study is to compare the enhancement properties of the two new gadolinium chelate(Gadospin-M and Gadospin-D)with a standard extracellular contrast agent(Magnevist)in an in-vivo study with a mouse brain glioma model in the 7 tesla MRI to compare two new relaxivity contrast media with a conventional contrast agent Magnevist.Method:Brucker 7.0T high field animal MRI is employed to scan.In our study,6 SPF nu-nu mouse is used to estamblished orthotopic model of the U87 glioma,All animals were first subjected to a high field 7.0 T MRI animal scanner(Brucker,Bio Spin,Germany),9 days and 11 days and 13 days after U87 tumor induction.The first time injection of contrast agent is Magnevist,the Gadospin-M,Gadospin-D.The contrast agent is administrated throuogh a tail vein catheter.All database images were reconstructed on post-processing workstation,the signal of the tumor and brain and background of the air are tested region-of-interest analysis to caculate the SNR,CNR,and LE.A veterinary histopathologist confirmed the presence of a glioma in each subject,after completion of the imaging study.Results:All the three contrast agents showed higher SNR than unenhanced.And the SNR of tumor was higer than normal brain after injection.The time to peak of SNR and LE with Gadospin M was earlier than Magnevist,and values of SNR and LE were always higer than Magnevist.The time to peak of SNR tumor with Gadospin D was earlier than the other two.But the LE with Gadospin D decreased most quickly and became less than Magnevist and Gadospin M in the late stage.The CNR of Gadospin M was the highest and Gadospin D was the lowest.The differences were statistically significant(p <0.05).Conclusions:The new contrast agent Gadospin M showed significantly more LE and CNR in comparison to Magnevist,suggesting that it showed better extravasation from tumor neocapillaries.The LE of Gadospin D is higher than Magnevist only in the early stage,though with higer SNR of tumor comparison with Magnevist.There was no significant difference of LE and CNR between Gadospin M and Gadospin D.Gd-Chelate contrast agent such as Gadospin M with low molecular weight and different three dimensional molecular structure is a promising preclinical and clinical contrast agent.