Ultrasmall Superparamagnetic Iron Oxides For Enhanced Magnetic Resonance Imaging To Detect Atheromatous Plaques Of Abdominal Aorta In Rabbits

Objective To investigate that whether USPIOs can be phagocytosed by macrophages within rabbit's abdominal aortic atheroma induced by high-cholestrol diet,if phagocytised, and whether magnetic susceptibility artifacts(MSAs) generated by SUPIOs particles within the atherosclerotic plaques is detectable and quantifiable by MRI.Material and methods The model of rabbit's abdominal aortic atheroma was made by means of balloon injury and high-cholestrol diet .After 4 months ,15 animals were randomly divided into group A1(n=10) and group A2(n=5).In addition, 5 healthy rabbits were used as a control group(groupB). SHU 555 C(200μmol/kg) was injected into rabbits of goup A1 and Group B,and 0.9% physiological saline into rabbits of group A2. Tridimensional gradient recall echo magenetic resonance angiography(3D-GRE MRA) was performed in group A1 befor and immediately and on days 1,3, 5 after an intavenous bolus of SHU 555 C.But in group A2 and group B,MRA was collected before and 5 days after injection. The Measurements of intraluminal signal to noise ratio(SNR) was performed on the precontrast image set as well as on the images collected immediately and on days ,1,3,5 after administation of SHU 555 C in group A1.The SNR of aortic walls was measured on the precontrast image set and on the images collected 5 days after injection in all 3 groups.The numerical value and percentage of reduction in transversal area were measured and calculated between precontrast and 5 days after injection in all 3 groups. After the last scan, all rabbits were executed to get aortic specimens,and stained with following: (1)hematoxylin and eosin (HE)stain;(2)Prussian blue stain.Rsults (1) Image analysis 3D MRA failed to reveal any visible difference between precontrast and 5 days after injection in group B and group A2.The aortic wall appeared...