Abstract #1543

Quarles C, Price R, Gore J

In this study we evaluate the utility of gas-filled, encapsulated microbubbles as an intravascular first pass susceptibility contrast agent for DSC-MRI in normal rat brain tissue. Microbubbles have a diameter and vascular distribution similar to that of red blood cells. On average, the maximum measured &[Delta]R2* following microbubble injection was 1/3 of that produced by 3 mg/kg of the iron oxide agent, ferumoxytol, at 9.4T. Unlike the rapid passage of ferumoxytol through cerebral tissue the duration of the microbubble signal enhancement was greatly prolonged, which prevented the calculation of microbubble flow using standard first pass tracer kinetic methods.