Abstract #1535

Assessment of Retinal and Choroidal Vascular Reactivity in Humans with Arterial Spin Labeling Perfusion Imaging

Nasim Maleki¹, David C. Alsop², Weiying Dai², Chris Hudson^3,4, David Mikulis¹, Jay Han⁵, Joseph A. Fisher^5,6

¹Department of Medical Imaging, University of Toronto, Toronto, ON, Canada; ²Department of Radiology, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, MA, USA; ³School of Optometry, University of Toronto, Waterloo, ON, Canada; ⁴Department of Ophthalmology & Vision Science, University of Toronto, Toronto, ON, Canada; ⁵Department of Anesthesiology, University of Toronto, Toronto, ON, Canada; ⁶Thornhill Research Inc., Toronto, ON, Canada

Some of the major causes of irreversible vision loss are characterized by a pathophysiologic vascular dysfunction element. The feasibility of measurement of the total blood flow to the retina with an optimized arterial spin labeling method has been described previously. In the current study, we hypothesized that ASL can be used to measure the changes in flow to the combined retinal and choroidal system induced by hypercarbic and hyperoxic stimuli in human. Our results indicate that a CO2 provocation challenge in combination with the ASL may be a promising approach to investigate choroidal vascular reactivity under normal and disease states.