Functional and metabolic magnetic resonance imaging (MRI) techniques have been rapidly evolving and have tremendous potential for clinical brain disorders research. Clinical activation functional fMRI studies are performed at 1.5 and at 3.0 Tesla using blood oxygenation level dependent (BOLD) contrast method and arterial spin tagging (AST) techniques. Reproducible alterations cerebral blood flow (CBF) have been performed having healthy controls inhale carbogen at 6 percent carbon dioxide with an approximate increase of 20 to 30 percent in CBF. These preliminary studies will allow us to perform pharmacological challenges and demonstrate the effects on CBF over multiple trials and doses that presently can not be performed using standard imaging techniques. Because of improvements in pulse sequences and phase array head coils for the 1.5 Tesla, single event functional MRI trials using AST pulse sequences can be performed. The results of these preliminary studies indicate that changes in CBF can be detected within 1 second when the healthy control performs a sensorimotor task. Future work will focus on improving the AST pulse sequences with background suppression to provide coverage over the whole head and also move the techniques to higher field strengths.
