ULTRAFAST PERFUSION-WEIGHTED MRI OF FUNCTIONAL BRAIN ACTIVATION IN RATS DURING FOREPAW STIMULATION - COMPARISON WITH T-ASTERISK(2)-WEIGHTEDMRI

A fast version of the arterial spin tagging technique for the detectio n of cerebral perfusion is presented, Based on adiabatic spin inversio n in combination with snapshot FLASH imaging, our technique allows the recording of perfusion changes with a temporal resolution of about 3 s. Differences of cerebral perfusion dependent on the choice of anesth esia were observed in rat brain, Furthermore, with this arterial spin tagging method we demonstrated perfusion increases in the somatosensor y cortex of anaesthetized rats during forepaw stimulation, Comparison of the activated areas in the T-2-weighted BOLD images and the perfus ion-weighted images showed good spatial correspondence, but the sensit ivity to the functional activation was more than ten times higher in t he perfusion technique.