The aim of the study was to compare the first-passage profiles of
dysprosium diethylenetriamine penta-
acetic acid bis(methylamide) (
DTPA BMA) and the superparamagnetic
iron oxide particles
NSR 0430 in regions with severe and moderate
cerebral ischemia. In seven rats subjected to
middle cerebral artery occlusion, two dynamic MR perfusion imaging series were acquired after intravenous bolus
injections of .5 mmol/kg
dysprosium DTPA BMA and .06 mmolFe/kg
iron oxide particles, respectively. The doses were chosen to obtain similar maximum signal change in normally perfused brain. The first-passage profiles were compared in a region of interest (ROI) in the core area with severe
ischemia and in a ROI in the penumbra area of moderate
ischemia. The results were compared both as the calculated mean signal intensity versus time curves for all seven rats and statistically for an estimated mean transit time (MTT) after gamma variate fitting of the calculated concentration versus time curves. The first-passage profiles for the two
contrast agents were similar, both in the core area of severe
ischemia and in the penumbra area of moderate
ischemia. In this rat
stroke model,
dysprosium DTPA BMA and the superparamagnetic
iron oxide particles
NSR 0430 were found to be equally efficacious for the diagnosis of the perfusion deficit, but if safe for human investigations,
iron oxide particles would have an advantage as equal susceptibility effect may be achieved with smaller injection volumes.