Application of Arterial Spin Labelling in Detecting Retinal Ischemia

Abstract

Purpose: Here, we have tried to quantify the chorioretinal blood perfusion in patients who are clinically identified to be suffering from retinal ischemia using arterial spin labelling (ASL) MRI. Method: Four participants, diagnosed with retinal ischemia based on their structural OCT and angiography test, were then scanned using anatomical MRI as well as ASL. We optimized MR parameters to maximize resolution and target fixation, blinking, and breathing ques to minimize motion artifacts. Results: Participants had a maximum of ∼50 mL/100 mL/min of blood perfusion, which is below the normal values of ∼200 mL/100 mL/min. It also appeared that thinning of the choroid contributes more to the measured decreased chorioretinal perfusion, compared to slowed arterial filling time. Conclusion: Decreased chorioretinal perfusion is a multifactorial event and has been implicated in several posterior eye pathologies. Based on our current results, it seems that ischemia of the eye could be due to anatomy (tissue volume) and/or functionality (arterial flow).