Continuous assessment of relative cerebral blood volume in transient ischemia using steady state susceptibility‐contrast MRI

Abstract

The utility of a noninvasive steady state susceptibility‐contrast MRI technique for continuous measurement of relative cerebral blood volume (rCBV) during global transient ischemia and subsequent hyperemia in a feline ischemia model is demonstrated. The measurements were obtained during a 10‐min period of occlusion and 1‐h period of reperfusion. Maximal hyperemic responses in gray matter, basal ganglia, and white matter (observed at 7,7, and 5 min, respectively) were 1.9 ± 0.5,1.8 ± 0.3, and 1.7 ± 0.6 times greater than baseline CBV (mean ± SEM). Thirty to forty minutes after onset of reperfusion, CBV returned to normal. Thereafter, it decreased below baseline, nearing the control level by 1 h after onset of reperfusion. Steady state susceptibility‐contrast MRI permits continuous, in vivo mapping of alterations in CBV.