EXPERIMENTAL ACUTE CEREBRAL-ISCHEMIA WITH REPERFUSION - EVALUATION WITH GADOLINIUM-TEXAPHYRIN

RATIONALE AND OBJECTIVES. The authors explore the potential usefulness of the new contrast medium gadolinium (Gd)-texaphyrin (PCI-0101) in m agnetic resonance imaging of experimental acute cerebral ischemia with reperfusion. METHODS. Four New Zealand white rabbits underwent 2 hour s of transorbital occlusion of the left internal carotid, anterior, an d middle cerebral arteries, followed by 2 hours of reperfusion with no rmal saline, Immediately thereafter, the rabbits were injected with 25 mu mol/kg of 2 mmol/L Gd-texaphyrin and killed by barbiturate overdos e, Postmortem T1- and T2-weighted coronal scans were performed at 1.5 Tesla and correlated with histopathologic findings. RESULTS. Postcontr ast T1-weighted images showed high signal within extensive cortical an d basal ganglia infarcts, Areas of high signal on T1-weighted images w ere less extensive than on T2-weighted images, and corresponded to onl y a portion of the region of neuronal damage seen histologically, Sign al intensity of infarcted brain on postcontrast T1-weighted images was significantly greater than normal brain in the contralateral hemisphe re (P < 0.0014). CONCLUSIONS. Experimental reperfused infarcts only 2 hours old demonstrate contrast enhancement with Gd-texaphyrin.