| 08:15 | 1181.
 | T1 measurement in CSF: Intrinsic compartmental differences and tracer concentration assessment in the healthy brain Tryggve Holck Storås1, Siri Fløgstad Svensson1, Sofie Lysholm Lian2, Geir Ringstad3,4, Ingrid Mossige1,2, Grethe Løvland5, Ragnhild Marie Undseth5, Kyrre Eeg Emblem1, and Kaja Nordengen2,6
1Department for Physics and Computational Radiology, Oslo University Hospital, Oslo, Norway, 2Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway, 3Department of radiology, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway, 4Department of Geriatrics and Internal Medicine, Sorlandet Hospital, Arendal, Norway, 5The Intervention Center, Oslo University Hospital, Oslo, Norway, 6Department of Neurology, Oslo University Hospital, Oslo, Norway Keywords: Neurofluids, Neurofluids Motivation: T1 mapping facilitates assessment of brain waste clearance by assessing native solutes or detection of endogenous tracers. Goal(s): To provide a method for accurate measurement of T1 in CSF, to investigate variations in intrinsic T1 of CSF and to measure tracer in CSF after intrathecal administration. Approach: A T2-weighted mixed spin-echo/inversion recovery sequence was implemented to measure T1 in CSF. Five healthy subjects were imaged prior to and four times after intrathecal gadobutrol injection. Results: Baseline R1 is lower in the ventricles than in the subarachnoid space. At 72 hours after injection, there is still gadobutrol in the subarachnoid space. Impact: Accurate T1 measurements in CSF facilitate quantitative study of brain clearance as concentration of Gd-based tracers in CSF can be established. Observed compartmental differences in intrinsic T1 of CSF indicate information on solute concentrations can be measured without endogenous tracer. |
| 08:27 | 1182.
 | Pre-surgical assessments of CSF flow and brain motion are indicative of improved cerebral dynamics following surgery in Chiari Malformation I Grace McIlvain1, Saeed Mohsenian2, Mohamad Motaz Al Samman2, Daniel L. Barrow1, Francis Loth2, and John N Oshinski 1
1Emory University, Atlanta, GA, United States, 2Northeastern University, Boston, MA, United States Keywords: Neurofluids, Neurofluids, Neurosurgery, Posterior Fossa Decompression, Chiari Malformation, DENSE, CSF Flow Motivation: Chiari Malformation I (CM-I) is a condition characterized by cerebellar tonsil herniation, leading to reduced cerebrospinal fluid (CSF) flow and various neurological symptoms. Posterior fossa decompression (PFD) surgery can relieve symptoms, but surgical decision making is often unclear. Goal(s): Tonsillar descent poorly correlates with symptoms and surgical outcomes. We seek to better characterize the cerebral dynamic effects of CM-I and PFD surgery. Approach: Measure CSF flow using PCMR, and brain motion using DENSE, before and after PFD surgery. Results: Surgery showed best improvement in patients with significantly restricted pre-surgical CSF flow or severely increased pre-surgical brain motion, regardless of amount of tonsillar descent. Impact: Presurgical indicators of an individual’s likelihood of surgical improvement are critical in developing informed care plans. We find that direct measures of cerebral dynamics outperform standard measures of tonsillar decent at predicting improvement from posterior fossa decompression surgery in CM-I. |
| 08:39 | 1183.
 | Distribution of intravenous Gadolinium-based contrast agents (GBCA) in human olfactory regions in healthy subjects Xinyi Zhou1,2,3, Sofia Garcia Del Barrio Cervera1,2,3, Yuanqi Sun1,2,3, Wei Li1,2, Licia Pacheco-Luna4, Haris I. Sair4, Adrian Paez1, Linda Knutsson1,5, Peter C.M. van Zijl1,2,3, Vidyulata Kamath6, Arnold Bakker5,6, Bryan Ward7, and Jun Hua1,2
1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 2Neurosection, Division of MRI Research, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States, 4Division of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 5Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 6Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 7Department of Otolaryngology - Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States Keywords: Neurofluids, Neurofluids, olfactory, DSC/DCE perfusion Motivation: Animal studies show that the olfactory pathway is a primary CSF clearance route. However, human studies using intrathecal-GBCA show that the olfactory route may be less involved in CSF clearance in humans. As most GBCA-enhanced MRI exams are still performed using intravenous-GBCA, it is essential to investigate GBCA dis-tribution in human olfactory regions after intravenous GBCA administration. Goal(s): To measure intravenous-GBCA-induced signal changes in olfactory regions. Approach: Dynamic-susceptibility-contrast-in-the-CSF (cDSC) MRI was performed in 25 healthy subjects. Results: Significant MR signal changes were detected in the olfactory regions following intravenous-GBCA. Extracranial regions showed more significant GBCA-induced changes than intracranial regions. Impact: GBCA-induced cDSC signal
changes were detected in olfactory regions of healthy subjects following
intravenous GBCA administration. Extracranial regions showed more significant
changes than intracranial regions, stressing the importance of separating these
areas when studying GBCA distribution using intravenous injection. |
| 08:51 | 1184.
 | Simultaneous arterial, venous, and CSF flow dynamics using interleaved multi-Venc spiral imaging Kevin M Johnson1 and Leonardo A Rivera Rivera1
1University of Wisconsin-Madison, Madison, WI, United States Keywords: Neurofluids, Neurofluids Motivation: Neurofluids dynamics are hypothesized to enable brain metabolite waste clearance pathways for healthy brain function including coupling between arterial, venous, and CSF fluid flow. Goal(s): To enable quantification of arterial, venous and CSF flow simultaneously leveraging interleaved multi-Venc phase contrast encoding and spiral sampling. Approach: A four-point velocity encoding scheme was integrated into a 2D golden angle spiral phase contrast sequence and used in studies of healthy subjects. The flow encoding collects multiple first moments at a fixed echo time. Results: The multi-Venc encoding scheme allowed for simultaneous measures of cardiac-resolved arterial, venous, and CSF flow. Impact: This work demonstrates a method for simultaneous arterial, venous, and CSF flow imaging for imaging neurofluid dynamics and their response to stimuli, challenges, and transient patient states. |
| 09:03 | 1185.
 | Impact of jugular vein ligation on cerebrospinal fluid clearance from G-lymphatic system in mice Anthony Ruze1,2, Laura Mouton1,2, Ruchith Singhabahu1, Joshua Gottschalk 1, Myriam Spajer1, Jean-Léon Thomas1,3, Stéphanie Lenck1,4, and Mathieu David Santin1,2
1Institut du Cerveau – Paris Brain Institute - ICM, Sorbonne Université, INSERM, CNRS, Paris, France, 2Centre de NeuroImagerie de Recherche – CENIR, Paris, France, 3Department of Neurology, Yale University School of Medicine, New Haven, CT, United States, 4Department of Neuroradiology, AP-HP, Pitié-Salpetrière, Paris, France Keywords: Neurofluids, Neurofluids Motivation: Cerebral venous outflow abnormalities have been linked to various neurological disorders, necessitating a detailed understanding of their impact on brain and lymphatic perfusion. This study aimed to investigate the G-lymphatic system change following bilateral jugular vein ligation (JVL) in mice. Goal(s): Deeper understanding of the venous system's role in CNS fluid homeostasis. Approach: JVL was performed in mice. 2D-TOF, DCE-FLASH and 3D-MGE imaging were acquired at baseline, 2, 7 and 14-days post-surgery. Quantitative analysis was used to assess changes in lymphatic flow, brain volumetry. Results: JVL induced hypertension, bigger brain and veinous system. The permeability in the brain reduced before returning to baseline. Impact: Our study demonstrated progressive alterations in cerebral blood flow in
mice following jugular vein ligation, highlighting the utility of MRI for
studying the G-lymphatic system in brain. These findings contribute to a better
understanding of cerebrovascular changes in living conditions. |
| 09:15 | 1186.
 | Monitoring pulsatile CSF motion in the subarachnoid space using MRI Zhiyi Hu1, Dengrong Jiang2, Yimei Cao1, Hongli Fan1, Wen Shi1, and Hanzhang Lu1,2,3
1Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD, United States Keywords: Neurofluids, Neurofluids Motivation: The characterization of pulsatile cerebrospinal fluid (CSF) flow within the subarachnoid space remains insufficiently understood, presenting a challenge in distinguishing CSF flow from blood flow. Goal(s): Our goal was to develop a time-efficient approach to monitor pulsatile CSF motion, independent of the pulsatile blood signal. Approach: We introduced a cardiac-gated BOLD sequence with flow-sensitive bipolar gradients to characterize CSF motion, and evaluated blood contamination using cardiac-gated arterial-spin-labeling. Results: We demonstrated that the main cause of the signal fluctuation is pulsatile CSF. The fluctuation patterns could be characterized by two components (hump and trough), which were consistently observe across subjects. Impact: The pulsatile CSF motion in the subarachnoid space can now be efficiently monitored with our method. This technique complements the ventricular CSF motion methods and together they may provide a better understanding of CSF and glymphatic circulation in the brain. |
| 09:27 | 1187.
 | Quantitative phase-contrast CSF-flow interleaved with cortical BOLD to measure glymphatic function via BOLD-CSF coupling Ingmar Eiling1,2, Emiel C.A. Roefs1,2, Jeroen de Bresser1, Matthias J.P. van Osch1, and Lydiane Hirschler1
1Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Equal contribution, ., Netherlands Keywords: Neurofluids, Neurofluids, Glymphatics Motivation: CSF-mediated brain waste clearance is implicated in proteinopathies such as Alzheimer’s disease. A better understanding of clearance mechanics is needed to understand pathological processes. Goal(s): To quantify flow- and pulsatility dynamics of CSF-motion in the 4th-ventricle using real-time phase contrast (rtPC) with interleaved BOLD-imaging while manipulating flow. Approach: rtPC is first interleaved with inflow-sensitized EPI to prove the same CSF-fluctuations are captured. Then, we show BOLD-CSF coupling between rtPC and cortical BOLD as well as between inflow-EPI and cortical BOLD during breathing and visual-stimulation paradigms. Results: rtPC improves characterization of CSF-flow in the 4th-ventricle compared to traditional BOLD-sequences, showing more coherent BOLD-CSF coupling. Impact: Clinical MR studies are increasingly looking at changes in BOLD-CSF coupling in patient populations as a measure of brain clearance efficiency. By interleaving phase contrast acquisitions with BOLD, we quantify CSF flow dynamics and obtain more robust BOLD-CSF measurements. |
| 09:39 | 1188.
 | Simultaneous 4D CSF flowmetry and BOLD fMRI using EPTI for investigation of neural activity evoked CSF flow responses Fuyixue Wang1,2, Timothy G. Reese1,2, Bruce R. Rosen1,2,3, Lawrence L. Wald1,2,3, Laura D. Lewis1,2,4, Jonathan R. Polimeni1,2,3, and Zijing Dong1,2
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Department of Radiology, Harvard Medical School, Boston, MA, United States, 3Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, 4Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States Keywords: Neurofluids, Neurofluids, Data Acquisition, fMRI Acquisition, CSF Flow Motivation: To investigate brain-wide CSF flow dynamics and how neural activity drives it. Goal(s): Develop a novel tool to simultaneously map CSF flow and T2*-BOLD fMRI with high sensitivity/specificity and effectively measure neural-activity-evoked CSF flow. Approach: Single-shot PGSE-EPTI is developed with high sensitivity to slow flow to acquire distortion-free phase-contrast flow velocity and directions, while simultaneously obtaining clean T2*-BOLD, T2, S0 contrasts with improved specificity. Results: Using the EPTI CSF flowmetry technique, brain-wide CSF dynamics were measured with high spatiotemporal details, and visual-task-evoked CSF flow responses were observed in both ventricles (global-response) and visual cortex subarachnoid space (local-response), synchronized with the simultaneously-acquired T2*-BOLD-fMRI signal. Impact: We developed a novel EPTI CSF-flowmetry technique to simultaneously map whole-brain CSF flow and T2*-BOLD-fMRI with high sensitivity/specificity for investigation of neural-activity-driven CSF flow. It successfully measured both global and local visual-task-evoked CSF flow responses in ventricles and visual-cortex subarachnoid-space. |
| 09:51 | 1189.
 | Using Real Time Phase contrast MRI to investigate CSF oscillations and aqueductal pressure gradients during free breathing Pan LIU1, Kimi Owashi2, Cyrille Capel3, Serge Metanbou4, and Olivier Balédent1,2
1Amiens Picardy University Hospital, CHIMERE UR.7516, Amiens, France, 2Jules Verne University of Picardy, CHIMERE UR 7516, Amiens, France, 3Amiens Picardy University Hospital, Neurosurgery Department, Amiens, France, 4Amiens Picardy University Hospital, Radiology Department, Amiens, France Keywords: Head & Neck/ENT, Brain, aquduct, respiratory effects, real time imaging, phase contrast, intracranial pressure Motivation: CSF dynamics is complex and regulates intracranial pressure. Pressure difference dynamics between the third and fourth ventricles (ΔPt) drives CSF oscillations in the aqueduct. MRI can quantify aqueduct anatomy and CSF oscillations. Goal(s): To quantify ΔPt during free-breathing by combining MRI anatomical imaging with real-time phase-contrast MRI. Approach: We developed a dedicated software to obtain: CSF flows dynamics Q(t), morphology of the aqueduct, its flow resistance (R) and ΔPt which equal R·Qt. Cardiac and breathing contributions to ΔPt were investigated in volunteers. Results: Contributions to ΔPt were 12.3 Pa and 9.5 Pa from cardiac and breathing respectively. Impact: Dedicated post-processing of real-time phase-contrast MRI allows quantification of CSF oscillations in the aqueduct and the pressure gradient between the third and fourth ventricles. Furthermore, continuous flow acquisition allows calculation of the cardiac and breathing influence on the pressure gradient. |
| 10:03 | 1190.
 | Fast 3D-EPI for characterization of CSF motion during the cardiac cycle. Pål Erik Goa1,2, Simon Blömer3, Rüdiger Stirnberg3, and Tony Stöcker3,4
1Department of Physics, NTNU, Trondheim, Norway, 2Clinic of Radiology and Nuclear Medicine, St.Olavs University Hospital HF, Trondheim, Norway, 3DZNE, Bonn, Germany, 4Department of Physics and Astronomy, University of Bonn, Bonn, Germany Keywords: Neurofluids, Brain Motivation: Individual variation in CSF dynamics may affect the efficiency of waste clearance from the brain. Goal(s): To develop a fast and sensitive MRI method for measurement of CSF motion during the cardiac cycle. Approach: Whole brain 3D-EPI at 3mm resolution and volTR=187ms was acquired at 7T for 94 seconds and retrospectively sorted into 20 cardiac phases based on pulse oximeter. Results: CSF dynamics was observed in all ventricles as well as in sub-arachnoid space, in addition to arterial pulsation. Both magnitude and phase pulsations were present in the 3 subjects acquired. Highest sensitivity to motion was observed along the phase-encoding direction. Impact: We show that fast 3D-EPI at 7T is very sensitive to the motion of CSF during the cardiac cycle. This method may be used to characterize CSF dynamics on individual patient level and aid understanding of brain diseases. |