Purpose: MRI methods sensitive to functional changes in cerebral blood volume (CBV) may map neural activity with better spatial specificity than standard functional MRI (fMRI) methods based on blood oxygen level dependent (BOLD) effect. The purpose of this study was to develop and investigate a vascular space occupancy (VASO) method with high sensitivity to CBV changes for use in human brain at 7 Tesla (T).
Methods: To apply 7T VASO, several high-field-specific obstacles must be overcome, e.g., low contrast-to-noise ratio (CNR) due to convergence of blood and tissue T1 , increased functional BOLD signal change contamination, and radiofrequency field inhomogeneities. In the present method, CNR was increased by keeping stationary tissue magnetization in a steady-state different from flowing blood, using slice-selective saturation pulses. Interleaved acquisition of BOLD and VASO signals allowed correction for BOLD contamination.
Results: During visual stimulation, a relative CBV change of 28% ± 5% was measured, confined to gray matter in the occipital lobe with high sensitivity.
Conclusion: By carefully considering all the challenges of high-field VASO and filling behavior of the relevant vasculature, the proposed method can detect and quantify CBV changes with high CNR in human brain at 7T.
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http://dx.doi.org/10.1002/mrm.24916 | DOI Listing |
Physiol Rep
January 2025
Department of Cardiovascular Medicine, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Ishikawa, Japan.
While autonomic dysregulation and repolarization abnormalities are observed in subarachnoid hemorrhage (SAH), their relationship remains unclear. We aimed to measure skin sympathetic nerve activity (SKNA), a novel method to estimate stellate ganglion nerve activity, and investigate its association with electrocardiogram (ECG) alterations after SAH. We recorded a total of 179 SKNA data from SAH patients at three distinct phases and compared them with 20 data from controls.
View Article and Find Full Text PDFFluids Barriers CNS
January 2025
Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, ON, Canada.
Background: Iduronate-2-sulfatase (IDS) deficiency (MPS II; Hunter syndrome) is a disorder that exhibits peripheral and CNS pathology. The blood brain barrier (BBB) prevents systemic enzyme replacement therapy (ERT) from alleviating CNS pathology. We aimed to enable brain delivery of systemic ERT by using molecular BBB-Trojans targeting endothelial transcytosis receptors.
View Article and Find Full Text PDFJ Intensive Care
January 2025
Medical and Infectious Diseases, ICU, Hospital Bichat-Claude Bernard, Université Paris Cité, AP-HP, Paris, France.
Background: Sepsis-associated encephalopathy (SAE) may be worsened by early systemic insults. We aimed to investigate the association of early systemic insults with outcomes of critically ill patients with severe SAE.
Methods: We performed a retrospective analysis using data from the French OUTCOMEREA prospective multicenter database.
Mol Brain
January 2025
Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu, 215006, China.
J Neuroinflammation
January 2025
Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
The thrombolytic protease tissue plasminogen activator (tPA) is expressed in the CNS, where it regulates diverse functions including neuronal plasticity, neuroinflammation, and blood-brain-barrier integrity. However, its role in different brain regions such as the substantia nigra (SN) is largely unexplored. In this study, we characterize tPA expression, activity, and localization in the SN using a combination of retrograde tracing and β-galactosidase tPA reporter mice.
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