SENSITIVITY ASSESSMENT OF QSM+qBOLD (or QQ) IN DETECTING ELEVATED OXYGEN EXTRACTION FRACTION (OEF) IN PHYSIOLOGICAL CHANGE

Motivation: Oxygen extraction fraction (OEF) is critical for assessing brain metabolism in neurological disorders. A recent QQ mapping technique successfully identified decreased OEF in chronic ischemia and hypercapnia, yet it's sensitivity to high OEF remains unexplored, which is crucial for investigating cerebrovascular disorders, including vascular dementia, where high OEF is expected. Comparing with a previous QSM-OEF method, we evaluated QQ's sensitivity to increased OEF values. Goal(s): Our goal is to investigate QQ's sensitivity to elevated OEF. Approach: We compared QQ-based OEF with QSM-OEF between resting state and hyperventilation in 11 healthy adults. Results: QQ showed significantly higher OEF in hyperventilation than in resting state. Impact: This study demonstrates QQ's sensitivity to physiologically increased OEF during hyperventilation. With high OEF expected in various cerebrovascular disorders, including vascular dementia and Parkinson's disease, this finding suggests that QQ can help in understanding abnormal brain metabolism in such disorders.