13:30 | 0981.
| Blood and CSF Dynamics During One Cardiac Cycle in the Healthy Brain Measured with Cine Phase-Contrast MRI Marco Muccio1,2, Zhe Sun1,2,3, Chenyang Li1,2,3, David Chu4, Lawrence Minkoff4, and Yulin Ge1,2 1Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York City, NY, United States, 2Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University Grossman School of Medicine, New York City, NY, United States, 3Vilcek Institute of Graduate Biomedical Sciences, New York University Grossman School of Medicine, New York City, NY, United States, 4FONAR Corporation, Melville, NY, United States Keywords: Neurofluids, Brain Motivation: Quantitative analysis of blood and CSF flow dynamics is vital to understand the intracranial pulsating fluid movement environment and its role in brain homeostasis. Goal(s): To characterize the correlation between blood (arterial/venous) and CSF flow within one cardiac cycle. Approach: Flow dynamic measurements in neck arteries and veins, cervical CSF (CSFc) and CSF in the aqueduct of Sylvius (CSFAq) were obtained using cine phase-contrast MRI from 18 healthy volunteers. Results: Net blood and CSFc flow wave curves depict a compensatory mechanism resulting in balance of total fluid inflow and outflow. CSFAq flow patterns mimic CSFc ones with some temporal delay. Impact: Understanding how blood and CSF flow influence each other in healthy subjects provides a reference frame to investigate alterations caused by neurological disease. We showed a dynamic interplay between neck blood and CSF flow at the cervical and aqueduct level. |
13:30 | 0982.
| Neuronal activity can drive cerebrospinal fluid flux via brain blood volume Benedikt Zott1,2,3, Juliana Zimmermann1,3,4, Clara Boudriot1, Christiane Eipert1, Gabriel Hoffmann1, Rachel Nuttall1,4, Sebastian Schneider1,3, Lena Schmitzer1, Jan Kufer1, Stefan Kaczmarz1, Dennis Martin Hedderich1, Andreas Ranft4, Daniel Golkowski5,6, Rüdiger Ilg5,7, Gerhard Schneider4, Josef Priller8,9,10, Claus Zimmer1, Christine Preibisch1,3, and Christian Sorg1,3,8 1Department of Neuroradiology, Technical University of Munich, School of Medicine and Health, Munich, Germany, 2TUM Institute for Advanced Study, Munich, Germany, 3TUM-Neuroimaging Center, Technical University of Munich, School of Medicine and Health, Munich, Germany, 4Department of Anesthesiology and Intensive Care, Technical University of Munich, School of Medicine and Health, Munich, Germany, 5Department of Neurology, Technical University of Munich, School of Medicine and Health, Munich, Germany, 6Department of Neurology, University of Heidelberg, Heidelberg, Germany, 7Department of Neurology, Asklepios Stadtklinik Bad Tölz, Bad Tölz, Germany, 8Deparment of Psychiatry and Psychotherapy, Technical University of Munich, School of Medicine and Health, Munich, Germany, 9Psychiatry, Charité - Universitätsmedizin Berlin and DZNE, Berlin, Germany, 10University of Edinburgh and UKI DRI, Edinburgh, United Kingdom Keywords: Neurofluids, Neurofluids Motivation: A driver of macroscopic CSF flux across ventricles and basal cisternae is hypothesized to be global cerebral blood volume, possibly induced by changes in brain-wide neuronal activity. Goal(s): We intended to test this hypothesis experimentally in healthy human subjects. Approach: We performed two experiments: (1) electro-encephalography and functional MRI (fMRI) during burst-suppression anesthesia, and (2) arterial spin labeling and fMRI during transient hypercapnic challenges in wakefulness. Results: Changes in brain blood volume, induced by neuronal activity switches during burst-suppression or brain blood flow during hyper-normocapnia transitions, cause fMRI signal changes in the basal cisternae which represent CSF flux from or into the brain. Impact: Two distinct experiments revealed a consistent and direct coupling
between macroscopic CSF flux and brain blood volume, which can be induced by
changes in global neuronal activity. This may contribute to perivascular CSF
flow and facilitate brain waste clearance. |
13:30 | 0983.
| Non-contrast MRI assessment of CSF drainage into superior sagittal sinus Dengrong Jiang1, Jie Song2, Yifan Gou3, Zhiyi Hu3, Wen Shi3, Zixuan Lin4, Abhay Moghekar5, and Hanzhang Lu1 1Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD, United States, 2Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States, 3Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, United States, 4Department of Biomedical Engineering, Zhejiang University, Hangzhou, China, 5Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, United States Keywords: Neurofluids, Neurofluids Motivation: The absorption of CSF into the superior-sagittal-sinus (SSS) is an important CSF drainage pathway and has been implicated in brain disorders like Alzheimer’s disease and idiopathic-intracranial-hypertension. However, we still lack non-invasive and non-contrast techniques to evaluate this CSF-venous drainage system. Goal(s): To develop a novel non-contrast MRI technique to assess the CSF drainage into the SSS. Approach: We propose to magnetically label the CSF spins and use a control-label subtraction to isolate signals from the CSF spins that have been absorbed into SSS. Results: In all subjects, we observed considerable signals from absorbed CSF spins in frontal SSS. Test-retest experiments demonstrated good reproducibility. Impact: We have
proposed a novel non-contrast MRI technique to assess the drainage of CSF into
the superior-sagittal-sinus, which may address an important technical gap in
evaluating the circulation of CSF. |
13:30 | 0984.
| Advancing Estimation of Microvascular Perfusion in the Choroid Plexus through Inversion Recovery Prepared IVIM MRI Chenyang Li1,2,3, Zhe Sun1,2,3, Eric E. Sigmund1,2, Jiangyang Zhang1,2, and Yulin Ge1,2 1Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States, 2Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States, 3Vilcek Institute of Graduate Biomedical Sciences, New York University Grossman School of Medicine, New York, NY, United States Keywords: Neurofluids, Diffusion/other diffusion imaging techniques, IVIM, diffusion, choroid plexus Motivation: Measuring vascular perfusion in the Choroid Plexus (ChP) is challenging due to its smaller size and the pronounced partial volume effects from CSF. Goal(s): To improve blood perfusion assessment of ChP utilizing Inversion recovery (IR) prepared IVIM imaging. Approach: Higher in-plane resolution (1.5x1.5mm2) IVIM diffusion MRI data with and without the IR preparation were acquired. The signal was analyzed using inverse Laplace transform (ILT) to estimate diffusion compartments within ChP for IVIM-derived perfusion fraction analysis.
Results: ILT analysis of IR-prepared IVIM revealed three diffusion compartments within the ChP and reported higher perfusion fraction observed in IR-prepared IVIM versus IVIM without IR-preparation. Impact: This study provides a novel approach to
investigate the microvascular perfusion in Choroid Plexus (ChP) with CSF signal
removed. IR preparation does not completely remove the free-diffusion
compartment but increases the microvascular perfusion fraction estimation in
ChP. |
13:30 | 0985.
| Artery-pulsation dependence of the paravascular cerebrospinal fluid flow measured by dynamic diffusion tensor imaging in human brain Guangxu Han1,2, Yinhang Jia1,2, Yi-Cheng Hsu3, and Ruiliang Bai1,2 1Key Laboratory of Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China, 2Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University School of Medicine, Hangzhou, China, 3MR Research Collaboration Team, Siemens Healthineers Ltd., Shanghai, China Keywords: Neurofluids, Neurofluids, Glymphatic system Motivation: There is still lack non-invasive methods to quantitative measure the paravascular cerebrospinal fluid (pCSF) flow speed and directions pulsations of arterial vessel . Goal(s): To explore whether dynamic DTIlow-b could capture the artery-pulsation dependence of pCSF flow in human and how DTIlow-b metrics are modulated by artery pulsation. Approach: Six-direction dynamic DTIlow-b was acquired simultaneously with finger pulse oximeter recording on eight subjects. Results: Both the axial and radial diffusivity of pCSF and whole-brain white matter is increased by artery dilation. DTIlow-b signal of pCSF at b = 0 mm2/s also shows artery-pulsation dependence but lags from diffusivity changes. Impact: The proposed dynamic DTIlow-b with ultra-long TE could potentially capture the volume and flow dynamics of MRI-visible and -invisible pCSF in artery pulsation. |
13:30 | 0986.
| Detection of vasomotion in the human brain using Fourier decomposition of T1-weighted Cine-FLASH MRI (FD-FLASH) Manuel Taso1, Humberto Mestre2, Geoffrey K Aguirre2, and John A Detre2,3 1Siemens Medical Solutions USA Inc, Malvern, PA, United States, 2Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States, 3Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States Keywords: Neurofluids, Neurofluids Motivation: Vasomotion has been hypothesized as a mechanism for brain paravascular clearance, which could be impaired in multiple neurodegenerative conditions. Goal(s): To measure vasomotion in vivo in human brains using MRI. Approach: A single-shot T1-weighted Cine-FLASH sequence was optimized to provide high temporal resolution in two adults, as well as during a visual stimulation paradigm in one. We performed a Fourier decomposition of the signal in brain vascular structures. Results: An ultra-low-frequency signal was observed consistent with vasomotion in posterior cerebral arteries while no such signal could be identified in the parenchyma. A substantial amplification of this signal could be observed during visual stimulation. Impact: This method could help
studying brain waste clearance and its dysfunction in humans in vivo. |
13:30 | 0987.
| Evaluation of the glymphatic system activity during sleep-wake states through quantitative CSF measurement using a three-pool water model Gawon Lee1 and Se-Hong Oh1 1Biomedical Engineering, Hankuk University of Foreign Studies, Yongin-si, Korea, Republic of Keywords: Alzheimer's Disease, Alzheimer's Disease, Glymphatic system, CSF Motivation: The glymphatic system plays a crucial role in brain waste clearance, and dysfunction has been linked to neurodegenerative diseases like Alzheimer's Disease. Understanding this system is essential for advancing our knowledge of brain health. Goal(s): We aim to develop a non-invasive method to assess glymphatic activity in the human brain. Approach: We utilize a quantitative CSF measurement technique with a three-pool model and multi-echo spin-echo images. Results: Significant variations in glymphatic activity were observed across different brain regions and found to be influenced by sleep. Impact: Our method can potentially reveal sleep-influenced
glymphatic activity variations, enabling early Alzheimer's Disease diagnosis. |
13:30 | 0988.
| Extracellular Volume Change in Human Brains during Sleep: A Simultaneous Sodium (23Na) MRI and EEG Study Xingye Chen1,2,3, Ying-Chia Lin1,2, Nahbila-Malikha Kumbella1, Simon Henin4, Zena Rockowitz5, Anli Liu4, Arjun Masurkar5, James Babb1,2, Yulin Ge1,2, Yvonne Lui1,2, and Yongxian Qian1,2 1Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States, 2Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States, 3Vilcek Institute of Graduate Biomedical Sciences, New York University Grossman School of Medicine, New York, NY, United States, 4Comprehensive Epilepsy Center, Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States, 5Alzheimer’s Disease Research Center, Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States Keywords: Neurofluids, Aging, Sodium MRI, EEG Motivation: Alzheimer's disease is associated with neurotoxic amyloid-beta(Aβ) plaques. Studies in mice demonstrate that impaired cerebrospinal fluid(CSF) clearance reduces Aβ clearance by 70%. Sleep enhances CSF clearance by expanding extracellular space. Goal(s): However, the impact of sleep on extracellular volume change remains unclear in human brains due to a lack of non-invasive technology. Approach: To address this gap, we use sodium(23Na) MRI to measure the extracellular volume fraction in 16 healthy human brains. We monitor the sleep stage with MRI-compatible Electroencephalography(EEG). Results: On average, a decrease in extracellular volume fraction was observed in the gray matter significantly, but not significant in the white matter. Impact: Our research may shed light on how sleep may
facilitate Aβ clearance in humans, bridging the gap between animal and human
studies. |
13:30 | 0989.
| Altered perivascular CSF mobility in human cerebral amyloid angiopathy Katerina Deike-Hofmann1,2, Paul Scheyhing1,2, Julia Nordsiek3, Andreas Decker2, Alexander Radbruch1,2, and Gabor Petzold2,3 1Clinic for Neuroradiology, Universityclinic Bonn, Bonn, Germany, 2German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany, 3Clinic for Neurology, Universityclinic Bonn, Bonn, Germany Keywords: Neurofluids, Neurofluids, Brain Clearance Motivation: Perivascular spaces (PVS) are mediating brain clearance, i.e. cerebrospinal fluid (CSF) - interstitial fluid exchange, and dilated PVS are a hallmark of cerebral amyloid angiopathy (CAA). However, until now, brain clearance function could not be assessed in humans in vivo. Goal(s): Goal of this study was to assess perivascular cerebrospinal fluid (CSF) mobility in CAA patients. Approach: A CSF mobility-specific 7-Tesla MRI sequence was applied for the first time in patients with CAA and healthy control (HC) subjects. Results: The study revealed perturbed CSF mobility in enlarged perivascular spaces in CAA compared to HC subjects, suggesting impaired perivascular clearance in CAA. Impact: With the finding of a perturbed CSF mobility in enlarged PVS in CAA patients, the study provides
proof-of-principal for in vivo measurements of perivascular CSF mobility
as a crucial component of the brain clearance pathway in health and disease. |
13:30 | 0990.
| CSF Outflow and Egress in Optic Nerve: Non-contrast MRI Revelations Diana Vucevic1, Vadim Malis1, Marin McDonald1, and Mitsue Miyazaki1 1Radiology, University of California San Diego, San Diego, CA, United States Keywords: Neurofluids, Neurofluids Motivation: The rose of cerebrospinal fluid (CSF) in neural health is recognized, yet its outflow and egress within the optic nerve, especially amidst new findings about the glymphatic system, remains less explored. Goal(s): Investigate CSF interactions within the optic nerve using advanced MRI techniques, highlighting implications for conditions like glaucoma. Approach: Utilized advanced Time-Slip sequences on a 3-T MR imager, targeting specific brain regions to study CSF outflow and egress. Results: Clear CSF egress pathways through the optic nerve were found, with distinct outflow influenced by participants’ optical attributes. Impact: Enhances understanding of CSF outflow and egress, providing pivotal insights for addressing neuro-ophthalmological disorders like glaucoma. |
13:30 | 0991.
| Dynamic measurement of concurrent BOLD and brain tissue displacement quantification in vivo at 7T using motion-encoded stimulated-echo EPI Amelia Strom1,2, Avery Berman2,3,4, Timothy G. Reese2, Zijing Dong1,2,5, Klaus Scheffler6, Laura D. Lewis2,7, and Jonathan R. Polimeni1,2,5 1Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 3Department of Physics, Carleton University, Ottawa, ON, Canada, 4University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Centre, Ottawa, ON, Canada, 5Department of Radiology, Harvard Medical School, Boston, MA, United States, 6Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 7Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States Keywords: Neurofluids, High-Field MRI, Tissue Characterization, Diffusion Acquisition, fMRI Analysis, Multi-Contrast Motivation: Understanding the spatiotemporal relationships between blood volume changes, tissue displacement, and CSF flow is important for elucidating brain waste clearance mechanisms, and measuring these compartments concurrently would enable effective analysis. Goal(s): To demonstrate the feasibility of leveraging both magnitude-valued and phase-valued data to measure BOLD fMRI and tissue motion simultaneously. Approach: We apply a combination of computer simulations and in vivo imaging with visual stimulation using the Displacement Encoding with Stimulated Echoes (DENSE) pulse sequence. Results: DENSE magnitude-valued data show significant response to visual stimulation in the visual cortex, while the phase-valued data show typical cardiac-gated motion in both cortex and brainstem. Impact: BOLD fMRI can be acquired simultaneously with brain tissue displacement quantification using the DENSE pulse sequence, enabling future spatiotemporal analyses of concurrent blood volume changes, tissue displacement, and CSF flow for understanding waste clearance mechanisms. |
13:30 | 0992.
| The effect of low frequency visual stimulation on CSF flow in the fourth ventricle measured with BOLD-fMRI Leon Munting1, Lydiane Hirschler1, Emiel Roefs1, Jasmin Keller1, Thijs van Harten2, Thijs van Osch1, Louise van der Weerd1, and Susanne van Veluw2 1Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Neurology, Massachusetts General Hospital, Boston, MA, United States Keywords: Neurofluids, fMRI (task based), CSF flow, brain clearance Motivation: Glymphatic clearance is impaired in neurodegenerative disease. Vasomotion has been suggested to drive CSF flow and influence clearance. Furthermore, low frequency sensory stimulation can enhance vasomotion. Whether low frequency visual stimulation can drive CSF flow in humans is still unclear. Goal(s): To study the effect of different visual stimulation frequencies on BOLD signal and CSF flow. Approach: 7T BOLD-fMRI scans were acquired in healthy volunteers watching a checkerboard flashing at 0.025, 0.05, or 0.1 Hz. Results: Visual cortex BOLD responses clearly oscillated at the stimulation frequencies, with increased power at lower frequencies. CSF flow responses observed in the fourth ventricle, however, were modest. Impact: This preliminary study confirms that BOLD
responses can be evoked locally in the brain with low frequency visual
stimulation, but that there is only modest effect on ventricular CSF flow. |
13:30 | 0993.
| Effect of visual stimulation on cerebrospinal fluid flow is impaired in glaucoma patients Ji Won Bang1, Carlos Parra1, Kevin Yu1, Gadi Wollstein1,2, Joel S Schuman1,3,4,5, and Kevin C Chan1,6 1Department of Ophthalmology, New York University Grossman School of Medicine, New York, NY, United States, 2Department of Biomedical Engineering, Tandon School of Engineering, New York University, New York, NY, United States, 3Wills Eye Hospital, Philadelphia, PA, United States, 4Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, United States, 5Department of Biomedical Engineering, Drexel University, Philadelphia, PA, United States, 6Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States Keywords: Neurofluids, Neurofluids Motivation: Glaucoma is an age-related neurodegenerative disease of the visual system. Recent studies suggested that glaucoma may lead to changes in cerebrospinal fluid (CSF) dynamics, which can be influenced by neural activity. However, it remains unclear how the CSF dynamics is altered in glaucoma. Goal(s): To test whether the impact of visual stimulation on CSF inflow is impaired in glaucoma. Approach: We used visually-evoked BOLD fMRI responses to compare the coupling between BOLD activity and CSF inflow across healthy individuals and glaucoma patients. Results: Our findings indicate that the influence of visual stimulation on CSF inflow decreases with glaucoma severity. Impact: Our findings suggest that CSF inflow is altered in glaucoma. Future studies should investigate whether this reduced impact of visual stimulation on CSF inflow is due to impaired neural activity or impaired interaction between cerebrovascular activity and CSF dynamics. |
13:30 | 0994.
| High-field contrast-enhanced magnetic resonance imaging demonstrates cerebrospinal fluid nasal efflux dynamics in vivo Kelley M. Swanberg1, Marios Kritsilis1, Nagesh Shanbhag1, Emily Johansson1, Jari Jukkola1, René In 't Zandt2, and Iben Lundgaard1 1Department of Experimental Medicine, Faculty of Medicine, Lund University, Lund, Skåne, Sweden, 2Bioimaging Centre, Faculty of Medicine, Lund University, Lund, Skåne, Sweden Keywords: Neurofluids, High-Field MRI, Cerebrospinal fluid efflux Motivation: The astroglia-mediated circulation of metabolites and waste between cerebrospinal fluid (CSF) and blood or lymph, recently termed the glymphatic system, is implicated in processes from autoimmunity to neurodegeneration. Goal(s): Many details of CSF dynamics, particularly efflux routes from brain to periphery including nasal pathways as we examine here, remain to be clarified. Approach: Here we investigate CSF efflux in living mice using 9.4-T in vivo dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Results: We show that gadolinium-based contrast agent injected into the cisterna magna (CM) of live mice dose-rate-dependently effluxes into the nasal mucosa in a manner affected by olfactory neuronal integrity. Impact: Controversy surrounds the current model of CSF efflux from brain ventricles to periphery. We show with high-field DCE-MRI in live mice that nasal efflux of CSF from cisterna magna adapts to both a flow rate challenge and olfactory neuronal damage. |
13:30 | 0995.
| Imaging GBCA enhancement in the periosteal and meningeal layers of dura mater using high resolution MRI at 7T Yinghao Li1,2,3, Yuanqi Sun1,2,3, Adrian Paez1, Linda Knutsson1,4, Peter C.M. Van Zijl1,2,3, and Jun Hua1,3 1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Kreiger Institude, Baltimore, MD, United States, 2Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Neurosection, Division of MRI Research, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States Keywords: Neurofluids, Neurofluids, CSF, dura mater Motivation: The GBCA enhancement detected in the parasagittal dura (PSD) is hypothesized to originate from the dura mater blood vessels lacking a blood-brain-barrier. The dura mater consists of two layers: periosteal and meningeal dura mater. No prior study has examined the pattern of GBCA enhancement within these layers. Goal(s): To visualize GBCA enhancement in the periosteal and meningeal layers of dura mater in the human brain. Approach: High-resolution black-blood and FLAIR MRI were performed at 7T. Results: The two layers and their GBCA-enhancement could be visualized. T1 and T2* values in each layer were measured. Impact: This work allows us investigate the relationship between GBCA-enhancement in the dura mater and GBCA-induced-signal-changes in the PSD and meningeal-lymphatic-vessels. This is of importance given that GBCA-enhanced MRI has been a gold-standard technique for investigating human brain clearance. |
13:30 | 0996.
| T2 selective saturation labeling for imaging of water exchange between tissues and CSF. David C Alsop1,2, Narjes Jaafar1,2, and Manuel Taso1,2 1Beth Israel Deaconess Medical Center, Boston, MA, United States, 2Harvard Medical School, Boston, MA, United States Keywords: Neurofluids, Neurofluids Motivation: Water exchange between tissue and CSF may contribute to CSF production and glymphatic clearance. The large difference in T2 between tissue and fluid suggests T2 saturation transfer can be used to image this exchange. Goal(s): We aimed to develop a method for water exchange imaging using T2 saturation. Approach: A novel strategy to control for systematic errors from direct effects of T2 saturation on fluid is proposed and evaluated in healthy volunteers. Results: Three dimensional images at longer TE show exchange signal surrounding the choroid plexus, but also more modest exchange near the cerebellar vermis and the cerebellar and cerebral cortices.
Impact: A new strategy for T2 selective water exchange
imaging can enable in vivo studies of CSF exchange that may reflect changes in glymphatic
clearance or CSF production with aging, Alzheimer’s disease, intracranial
hypertension and other disorders. |
13:30 | 0997.
| Distinct Effects of Respiratory Depth and Frequency on CSF Flow Makaila N Banks1,2,3, Harrison Fisher2,3,4, Baarbod Ashenagar2,4,5, Daniel E. P. Gomez2,3,6, Jonathan R. Polimeni2,6,7, Vitaly Napadow2,3, and Laura D. Lewis2,3,4 1Graduate Program for Neuroscience, Boston University, Boston, MA, United States, 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 3Institute for Medical Engineering and Science, Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 4Department of Biomedical Engineering, Boston University, Boston, MA, United States, 5Institute for Medical Engineering and Science, Electrical Engineering and Computer Science, Massachusetts General Hospital, Cambridge, MA, United States, 6Department of Radiology, Harvard Medical School, Cambridge, MA, United States, 7Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States Keywords: Neurofluids, Neurofluids, Cerebrospinal Fluid Flow, CSF, phase contrast, velocity Motivation: The flow of cerebrospinal fluid (CSF) is essential for maintenance of brain function. Goal(s): We aimed to understand the effects of respiration on CSF flow dynamics by quantitatively testing the change in CSF flow across varying paced breathing frequencies. Approach: Using flow-sensitive fMRI, phase contrast imaging, and physiological recordings, we measured changes in CSF flow and velocity during a visually guided paced breathing task. Results: We examined CSF flow across breath frequencies ranging from 0.1 Hz to 0.25 Hz, and found that slower frequencies of breathing increase CSF flow, independent of breath depth. Impact: Our results demonstrate that key features of human
respiration, its timing and its depth, induce
separate effects on CSF flow. Our identification of
respiratory frequency as a modulator of CSF flow provides an accessible mechanism
to modulate CSF flow. |
13:30 | 0998.
| Test-retest reliability of coupling between cerebrovascularoscillations and cerebrospinal fluid flow fluctuations Weiwei Zhao1, Tianxin Mao1, Yao Deng1, and Hengyi Rao1 1Center for Magnetic Resonance Imaging Research & Key Laboratory of Brain-Machine Intelligence for Information Behavior (Ministry of Education and Shanghai), Shanghai International Studies University, Shanghai, China Keywords: Neurofluids, Reproductive, gBOLD-CSF coupling, Glymphatics, Sleep deprivation Motivation: The coupling strength of global blood-oxygen-level-dependent (gBOLD) signals and cerebrospinal fluid (CSF) inflow have been suggested to be an indicator of glymphatic system function. However, few studies have validated its test-retest reproducibility. Goal(s): To assess the reproducibility of gBOLD-CSF coupling. Approach: Thirteen adults of the sleep deprivation (SD) group and 14 adults of the control group underwent three fMRI. The reliability of gBOLD-CSF coupling was evaluated by the intraclass correlation coefficient (ICC). Results: A higher ICC (0.525, P = 0.001) was observed in the control group compared with the SD group (0.137, P = 0.086). Impact: The gBOLD-CSF coupling shows good reproducibility, but care should be taken when interpreting longitudinal changes of the gBOLD-CSF coupling that may be influenced by participants’ drowsiness. Sleep should be considered an important factor in future studies exploring the glymphatic system. |
13:30 | 0999.
| Localized convolutional function regression: A computational method for measuring interstitial fluid flow and perfusion in DCE-MRI Ryan Woodall1, Cora Esparza2, Margarita Gutova1, Maosen Wang2, Jessica Cunningham2, Alexander B Brummer3, Caleb Stine2, Christine C Brown1, Jennifer M Munson2, Jennifer M Munson2, and Russell C Rockne1 1City of Hope, Duarte, CA, United States, 2Fralin Biomedical Institute, Virginia Polytechnic Institute, Roanoke, VA, United States, 3College of Charleston, Charlston, NC, United States Keywords: Neurofluids, Perfusion Motivation: Aggressive gliomas are known to migrate in the direction of interstitial fluid flow (IFF), though it is difficult to measure interstitial fluid flow using MRI. Goal(s): Our goal is to develop a computational method for measuring IFF using DCE-MRI. Approach: We developed localized convolutional function regression (LCFR), validated in silico, in porous hydrogel, and apply it to in vivo tumors. Results: LCFR accurately measures fluid flow and perfusion to less than 10% error in silico, and measures IFF in a mouse model of glioma to be 1.63E-3 mm/s. In a case study, the method tentatively predicts invasion across the corpus collosum. Impact: This method will allow physicians and researchers to investigate how highly aggressive gliomas invade healthy tissue, and can be further used to predict how therapeutic agents or cells will disperse throughout the tumor, predicting disease progression and response. |
13:30 | 1000.
| Detecting magnetization exchange between human brain tissue and CSF compartments using selective parenchyma spin labeling and CSF imaging Dahan Kim1, Yujia Huang1, and Jiaen Liu1,2 1Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 2Department of Radiology, UT Southwestern Medical Center, Dallas, TX, United States Keywords: Neurofluids, Neurofluids, CSF, MT, magnetization transfer Motivation: While challenging in humans, measuring fluid exchange between the brain parenchyma tissue and CSF compartments is essential for understanding the role of CSF-mediated metabolic waste clearance in neurodegeneration. Goal(s): We demonstrate the feasibility of detecting such fluid exchange in human brains, unaffected by CSF-flow and partial-volume artifacts. Approach: Free-water spins inside parenchyma were selectively saturated and labeled by magnetization transfer, and subsequent partial saturations were quantified within CSF compartments. Results: We found 3.6% saturation in subarachnoid space (SAS), significant saturation difference between SAS and lateral ventricles (1.3%), and higher saturations in slow-flowing, narrow compartments (e.g. SAS and longitudinal fissure) than larger ventricle spaces. Impact: We demonstrated feasibility of detecting fluid exchange between brain parenchyma and CSF compartments in human brains through selective parenchyma saturation and CSF saturation quantification. Measuring such exchange is important for understanding the role of CSF-mediated metabolic waste clearance in neurodegeneration. |