Abstract #2907

Allegrini P, Weidensteiner C, McSheehy P

Small molecular contrast agent (CA) are less than ideal dynamic for contrast enhanced MRI since the rate limiting step of CA extravasation may be either vascular permeability or blood perfusion in the immature blood vessels. The influence of perfusion variations can be reduced by using macromolecular CA. In this study we measured the effect of anti-VEGF treatment on transfer constant Ktrans of two different tumor models with the small Gd chelate GdDOTA and the macromolecular CA Vistarem in the same animals. The effect of VEGF antagonist on Ktrans resulted in a higher dynamic range when measured with the macromolecular CA.