BOLD Calibration:Arterial Spin Labeling (ASL)

Measurement of CBF

Motivation• Cerebral Blood Flow (CBF) influences the

BOLD Signal• Provide a measure of vascular reactivity

ASL(Arterial Spin Labeling)

• Uses RF inversion to “tag” blood and measure where it goes.

Proposed Work Plan

• Year 1: select, implement and test an ASL method

• Year 2: Parametric assessment of ASL variables

• Year 3: Develop algorithms for using baseline CBF in BOLD activation calculation

• Year 4: Validate at sites• Year 5: Incorporate into the fBIRN protocol

Cocaine

• Observed brain hypoperfusion after 6 months of abstinence

• May be to due to impaired cerebral vascular response

• Measure CBF during a vascular challenge (breathhold) to assess vascular reactivity