Detection of blood volume changes in the rat kidney using an intravascular USPIO contrast agent
Storey P, Ji L, Li L, Prasad P
Evanston Northwestern Healthcare, Northwestern University Feinberg School of Medicine
Endothelial function is important in maintaining organ homeostasis, and can be assessed by monitoring vascular responses to mechanical and pharmacological maneuvers. In this study we investigated the potential of MRI in combination with an intravascular USPIO contrast agent ferumoxytol to monitor changes in blood volume noninvasively. Systemic vasodilation was induced in rats by intravenous infusion of adenosine, and the resulting R2 changes in the kidney were monitored using a CPMG sequence. Following injection of ferumoxytol (8mg Fe/kg) the R2 responses to adenosine infusion (500&[mu]g/kg/min) in the renal cortex, outer medulla and inner medulla were 8.3&[plusmn]1.7s-1, 15.8&[plusmn]3.7s-1 and 13.8&[plusmn]1.4s-1 respectively (mean&[plusmn]SEM).