Ultrahigh field MRI with field strengths at or above 7 Tesla, allows neuroscientists to collect detailed images of very small structures in the brain, such as subfields of the hippocampus, a key structure damaged in aging and neurodegenerative diseases. Ultrahigh field MRI also offers increased resolution and contrast for studying blood vessels in the brain from large arteries to very small lenticulostriate arteries with a diameter of less than one millimeter. This ability is critical for advancing studies of cerebrovascular disease, including stroke and cerebral small vessel disease. Another innovation of 7T MRI is visualization of perivascular spaces, fluid-filled regions surrounding the brain’s blood vessels, which are involved in waste clearance. Ultrahigh field MRI also offers an increased sensitivity to blood flow and blood oxygenation for functional imaging studies, revealing fine-grained microvascular blood flow and blood oxygenation signals across cortical layers. With its increased BOLD and perfusion signals, excellent visualization of cerebral vasculature from large arteries to very small lenticulostriate arteries, as well as perivascular spaces, ultrahigh field MRI can help researchers understand the physiological and functional changes in neurodegenerative diseases such as Alzheimer’s by studying the link between neuronal activity, vascular architecture, blood flow, and blood oxygenation.
ISMRM High Field Study Group 2021 Video Challenge Awardee