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Abstract #1634

An Alternative Technique for Measuring Cerebrovascular Reactivity; Comparing Cued Deep Breathing Hypocapnia with Inspiration of Carbon Dioxide

Molly Gallogly Bright1,2, Daniel P. Bulte2, Peter Jezzard2, Jeff H. Duyn1

1Advanced MRI Section, LFMI, NINDS, National Institutes of Health, Bethesda, MD, USA; 2FMRIB Centre, Department of Clinical Neurology, University of Oxford, Oxford, UK

Recently we introduced a novel respiratory technique, cued deep breathing (CDB), which induces robust BOLD signal decreases. The strong, short-lived response to CDB allows for whole-brain spatial and temporal characterization of cerebrovascular reactivity, and CDB is suitable for a broad range of clinical situations. We have directly compared the quantitative effects on end-tidal gas levels and BOLD signal of CDB and a traditional hypercapnia 4% CO2 gas challenge. CDB induced up to 7.00.7 mmHg decreases in end-tidal CO2 and the resulting reactivity maps show good correlation with the CO2 study, indicating CDB offers easy access to similar information.