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Abstract #0473

Measurement of Parenchymal Extravascular R2* Using Multi-Echo VASO MRI at 7T

Ying Cheng1, 2, Peter C. M. van Zijl, 23, Jun Hua, 24

1Dept. of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2F. M. Kirby Research Center for Functional Brain Imaging, KKI, Baltimore, MD, United States; 3Neurosection, Div. of MRI Research, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 4Neurosection, Div. of MRI Research, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore , MD, United States

Extravascular R2* is an important parameter for quantitative BOLD studies and has been previously determined at 1.5T and 3T. At 7T, only changes in R2* (ΔR2*) upon neuronal stimulation have been reported. In this study, we employed multi-echo vascular-space-occupancy (VASO) MRI to measure absolute parenchymal extravascular R2* values in human brain at 7T. Average extravascular R2* values in human visual cortex at 7T were 43.782.82 s-1 at baseline and 42.713.32 s-1 during visual stimulation (n=4). The extravascular BOLD contributions at 7T were estimated with the ratio of extravascular to total R2* changes during stimulation to be 9011%.

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Keywords

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