Abstract #0757

Does VASO Contrast Really Allow Measurement of CBV at High Field ( &[ge]7T)? An In-Vivo Quantification Using Concurrent Optical Imaging Spectroscopy.

Aneurin James Kennerley¹, Laurentius Huber², Toralf Mildner², John Edward Mayhew¹, Robert Turner³, Harald E. Mller², Jason Berwick¹

¹Faculty of Science, University of Sheffield, Sheffield, South Yorks., United Kingdom; ²Nuclear Magnetic Resonance Unit, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; ³Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany

This in-vivo study quantifies a slice-selective-saturation (SSS) vascular space occupancy (VASO) fMRI sequence for measurement of Cerebral Blood Volume (CBV), at high field (7T). We compare SSS-VASO signal contrast with concurrent measurements of total hemoglobin (HbT) using 2-dimensional optical imaging spectroscopy (2D-OIS) in rat somatosensory cortex. VASO derived CBV changes are in good agreement in terms of both magnitude and temporal dynamics with HbT changes during both electrical stimulation and hypercapnic challenge. We observe 5-10% changes in CBV to stimulation in the rodent model - much lower than previously reported changes in human visual cortex (30-40%).