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| 4919.
 | The relation between sleep indices and indices for brain interstitial fluid dynamics by MRI and the effects of orexin antagonists: a FLUID study. Toshiaki Taoka1,2, Kunihiro Iwamoto3, Seiko Miyata3, Ippei Okada3, Rintaro Ito1,2, Rei Nakamichi2, Toshiki Nakane2, Kazushige Ichikawa4, Hirohito Kan5, Koji Kamagata6, Junko Kikuta6, Shigeki Aoki6, Akihiro Fujimoto7, Yuki Kogo7, Nobuyasu Ichinose1,8, Shinji Naganawa2, and Norio Ozaki9
1Department of Innovative Biomedical Visualization (iBMV), Nagoya University, Nagoya, Japan, 2Department of Radiology, Nagoya University, Nagoya, Japan, 3Department of Psychiatry, Nagoya University, Nagoya, Japan, 4Department of Radiological Technology, Nagoya University, Nagoya, Japan, 5Department of Integrated Health Sciences, Nagoya University, Nagoya, Japan, 6Department of Radiology, Juntendo University of Medicine, Tokyo, Japan, 7Medical Headquarters, Eisai Co., Ltd., Tokyo, Japan, 8Department of CT-MR Solution Planning, Canon Medical Systems Corporation, Otawara, Japan, 9Pathophysiology of Mental Disorders Nagoya University Graduate School of Medicine, Nagoya University, Nagoya, Japan Keywords: Neurofluids, Neurofluids Motivation: The motivation is to investigate the relationship between sleep and interstitial fluid dynamics influenced by the administration of lemborexant, a dual orexin receptor antagonist. Goal(s): The goal is to identify changes in indices of interstitial fluid dynamics related to sleep before and after the administration of lemborexant. Approach: ALPS-index, Ktrans by DSC method, and choroid plexus volume were assessed as indicators of interstitial fluid dynamics. Results: The sleep indexes on a night were found to correlate with the ALPS-index measured in the evening before that night's sleep. In multiple regression analysis, the ALPS-index was lower when sleep parameters were poor at baseline. Impact: The sleep indexes on a night were found to correlate with the ALPS-index measured the evening before. The evaluation of the ALPS-index before and after
lemborexant administration revealed that the baseline sleep status played a
role in improving the index. |
| 4920.
 | Altered blood pulsatility & small vessel disease marker associations in obstructive sleep apnoea post-continuous positive airway pressure Michael S Stringer1, Lizzie Hill2, Alasdair Morgan1, Dany Jaime Garcia1, Lucia Ballerini3, Will Hewins4, Rosalind Brown1, Roberto Duarte Coello1, Bradley Macintosh5,6, Jose Bernal7, Andrew Lim6,8, Rosa Sommer6,8, Maria Valdes Hernandez1, Francesca Chappell1, Sandra Black6, Ian Marshall1, Fergus Doubal1, Renata Riha9, Michael J Thrippleton1, and Joanna M Wardlaw1
1Centre for Clinical Brain Sciences and UK Dementia Research Institute, University of Edinburgh, Edinburgh, United Kingdom, 2School of Applied Sciences, University of the West of England, Bristol, United Kingdom, 3University for Foreigners of Perugia, Perugia, Italy, 4School of Health in Social Science, University of Edinburgh, Edinburgh, United Kingdom, 5Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 6Hurvitz Brain Sciences Program, Sunnybrook Research Institute, Toronto, ON, Canada, 7Institute of Cognitive Neurology and Dementia Research, Otto-Von-Guericke University and DZNE Magdeburg, Madgeburg, Germany, 8Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada, 9Department of Sleep Medicine, Royal Infirmary of Edinburgh, NHS Lothian, Edinburgh, United Kingdom Keywords: Neurofluids, Blood vessels, Phase contrast MRI Motivation: Sleep affects vascular health and brain waste clearance. Sleep disorders, including obstructive sleep apnoea (OSA), are associated with higher small vessel disease (SVD) burden increasing stroke/dementia risk. OSA treatment relies on continuous positive airway pressure (CPAP). Goal(s): We aimed to assess the effect of CPAP on MRI-based blood pulsatility index (PI) measures and associations with SVD burden. Approach: We assessed arterial/venous PI using phase-contrast MRI in patients with moderate/severe OSA before and after 4 months CPAP. Results: Arterial PI tended lower post-CPAP, consistent with better vascular health. Post-CPAP patients with higher venous PI had less severe basal ganglia perivascular space burden. Impact: Few studies have investigated MRI-based blood pulsatility
index (PI) in obstructive sleep apnoea (OSA). We found effective treatment may
improve brain vascular health, altering blood PI. Higher venous PI
post-treatment may link to brain waste clearance, but requires further study. |
| 4921.
 | The role of glymphatic function and CSF circulation in patients with glioma Xiaodan Liu1, Angela Jakary1, Oluwaseun Adegbite1, Tracy Luks1, Reza Eghbali1, Villanueva-Meyer Javier1, Susan Chang2, Duan Xu1, and Janine Lupo1
1Radiology and Biomedical imaging, University of California, San Francisco, San Francisco, CA, United States, 2neurological surgery, University of California, San Francisco, San Franciso, CA, United States Keywords: Neurofluids, Tumor, CSF circulation, glymphatic system, Diffusion tensor imaging analysis along the perivascular space (ALPS) Motivation: Limited research has been performed on the role of CSF circulation in the glymphatic transport in patients with glioma. Goal(s): To evaluate the relationship between CSF circulation disturbance and glymphatic dysfunction in different glioma subtypes. Approach: A novel measure of glymphatic function (ALPS index) was quantified and compared among 100 patients with different genetic subtypes and associated with CSF circulation related factors and tumor volume. Results: We found that lower ALPS index in the tumor hemisphere was found in IDH-wildtype glioblastomas and with increasing grade in IDH-mutant gliomas. CSF circulation related factors were correlated with disruptions in glymphatic function. Impact: Our promising results provide a novel insight of glymphatic dysfunction in patients with glioma. |
| 4922.
 | Improvement of Glymphatic System Using Low-Intensity Focused Ultrasound (LIFU) for Lymphatic Enhancement Hyochul Lee1,2, Taekyu Jang1,2, Ok kyu Park2,3, Taewon Choi4, Seoyun Chang4, Jinhyoung Park4, and Seung Hong Choi1,2,3
1Interdisciplinary Program in Cancer, Seoul National University, Seoul, Korea, Republic of, 2Department of Radiology, Seoul National University Hospital, Seoul, Korea, Republic of, 3Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, Korea, Republic of, 4Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do, Korea, Republic of Keywords: Neurofluids, Brain, Glymphatic system, Low-Intensity Focused Ultrasound, Lymphatic Enhancement, Contrast-enhanced MRI Motivation: Enhanced lymphatic flow may improve the glymphatic system for metabolic waste clearance from the brain. Goal(s): Our goal was to demonstrate that stimulating the lymphatics can enhance the glymphatic system. Approach: We introduced low-intensity focused ultrasound (LIFU) to enhance the lymphatics and assessed the glymphatic system in rats by visualizing signal changes in contrast-enhanced MRI. Results: The LIFU group exhibited a more rapid increase and decrease in signal intensity compared to the control group. Impact: Lymphatic enhancement using LIFU could influence the improvement of the glymphatic system. This enhancement could positively affect cognitive function, with potential implications for preventing and treating neurodegenerative diseases. |
| 4923.
 | How Breathing and Cardiac functions interact with Cerebral arterio-venous blood flows: Origin of CSF oscillations Pan LIU1, Kimi Owashi2, Heimiri Monnier2, 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: Neurofluids, Neurofluids, Real time, phase contrast, CSF, CBF Motivation: The main drivers of CSF oscillations are currently controversial. Goal(s): To investigate whether the breathing or cardiac regulated Cerebral blood flow are the major driver of CSF dynamics. Approach: Investigate Cerebral blood and CSF flows through the intracranial compartment during free and deep breathing using real-time phase-contrast sequence. To quantify the neurofluids volume displacement along the cardiac cycle. Results: Both cardiac and breathing cycles influenced neurofluids volume displacements. CSF dynamics is significantly correlated with intracranial blood volume change. CSF dynamic acts as a compensatory mechanism of intracranial blood volume dynamics. Impact: This study confirms that intracranial blood volume change due to cardiac and breathing activities are the main drivers of CSF dynamic. This study provides valuable insights for understanding CSF circulation's complex mechanism and investigating idiopathic cerebral diseases. |
| 4924.
 | MR Elastography as a Potential Imaging Biomarker and Non-Invasive Method for Diagnosing Spontaneous Intracranial Hypotension Ian Mark1, Pragalv Karki2, Jeremy Cutsforth-Gregory2, Waleed Brinjikji2, Ajay Madhavan2, Steven Messina2, Petrice Cogswell2, John Chen2, Richard Ehman2, John Huston2, and Matthew Murphy2
1Radiology, Mayo Clinic, Rochester, MN, United States, 2Mayo Clinic, Rochester, MN, United States Keywords: Neurofluids, Elastography, SIH; CSF Leak Motivation: Spontaneous intracranial hypotension (SIH) is a debilitating disease with a normal brain MRI in 20% of cases. Goal(s): Our goal was to use MR elastography (MRE) to identify unique viscoelastic patterns in SIH patients. Approach: We performed brain MRE in 15 SIH patients and compared their mechanical properties to 65 healthy controls. Results: SIH patients exhibited significant differences in both stiffness and damping ratio compared to healthy controls. Impact: We demonstrate MRE as a potential imaging biomarker and a
non-invasive method for diagnosing SIH, including patients with a normal brain
MRI. |
| 4925.
 | Interaction of neurofluids flow dynamics studied by PC-MRI Kimi Piedad Owashi1,2, Pan Liu1,2, Serge Metanbou3, Cyrille Capel2,4, and Olivier Balédent1,2
1Medical Image Processing, University Hospital, Amiens, France, 2CHIMERE UR 7516, Jules Verne University of Picardy, Amiens, France, 3Radiology, University Hospital, Amiens, France, 4Neurosurgery, University Hospital, Amiens, France Keywords: Neurofluids, Neurofluids Motivation: Cervical-level is often chosen to estimate Cerebral Blood-Volume Change (CB-VC) during cardiac cycle. Due to the heterogeneity in extracranial cerebral veins anatomy and their high compliance, we hypothesize that the intracranial level could be a better choice to investigate blood and CSF interactions. Goal(s): To determine the best level for studying the interaction of neurofluids flow dynamics. Approach: Using PC-MRI, CB-VC and CSF-Volume Change (CSF-VC) were calculated in 36 volunteers at intracranial and extracranial levels, and their interactions were compared by linear regressions. Results: The interaction between CSF-VC and CB-VC dynamics at intracranial level (R2:0.82±0.16) was higher (p<0.001) than at extracranial level (R2:0.46±0.36). Impact: This study highlights the greater consistency of spinal CSF-VC response to vascular volume dynamics measured intracranially rather than at the cervical level. These findings are valuable to consider for studying cranio-spinal neurofluids flow dynamics interactions, pressure and compliance. |
| 4926.
 | Exploring the development of glymphatic system function in very preterm infants through the diffusion along perivascular space index Congcong Liu1,2, Chunxu Da1,2, Xinyi Huang1,2, Tianjiao Chen1,2, Miaomiao Wang1,2, Xianjun Li1,2, and Jian Yang1,2
1Department of Radiology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China, 2Shaanxi Engineering Research Center of Computational Imaging and Medical Intelligence, Xi'an, China Keywords: Normal Development, Neonatal Motivation: Despite white matter perivascular spaces visual grades in preterm was not different from term infants, whether the glymphatic system function differently with preterm and term infants remains unclear. Goal(s): Exploring development of glymphatic system function in very preterm (VP) infants, comparing with term infants. Approach: The diffusion along perivascular space index (ALPS) was used to evaluate the glymphatic system function via diffusion tensor images (DTI). Results: The DTI-ALPS index was significantly lower in VP neonates than VP infants at term equivalent age (TEA) or term neonates. However, the DTI-ALPS index in VP infants at TEA was not found differences with term neonates. Impact: The glymphatic system function was developing with gestational age, while very preterm infants presented “catch-up” growth pattern up to TEA. |
| 4927.
 | Diffusion tensor imaging analysis along the perivascular space in different burdens of cerebral small vessel disease Na Wang1, Meng Li2, Jing Li3, Xinyue Zhang1, Changhu Liang1, and Lingfei Guo1
1Key Laboratory of Endocrine Glucose & Lipids Metabolism and Brain Aging, Ministry of Education; Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China, 2Department of Psychiatry and Psychotherapy, Jena University Hospital, Jena, Germany; Center for Intervention and Research on adaptive and maladaptive brain Circuits underlying mental health (C-I-R-C), Jena-Magdeburg-Halle, Germany, Jena, Germany, 3Department of Radiology, Beijing Tsinghua Changgung Hospital, Beijing, China Keywords: DWI/DTI/DKI, Diffusion Tensor Imaging, Diffusion Tensor Imaging along the Perivascular Space Motivation: Cognitive decline is associated with the impairment of glymphatic clearance, which can be investigated noninvasively using diffusion tensor imaging along the perivascular space (DTI-ALPS). Goal(s): To investigate the linkage of cerebral small vessel disease (CSVD) burdens with left/right glymphatic function based on DTI-ALPS. Approach: Glymphatic system function was assessed using diffusion tensor imaging along the perivascular space. Results: The DTI-ALPS indexes in the CSVD groups were lower than the HC group. Hazard factors for right DTI-ALPS included CSVD severity and sex. Although the right DTI-ALPS index was associated with cognition in univariate analysis, it was not significant in regression analysis. Impact: The DTI-ALPS
technique provides a new opportunity for exploring the damage of CSVD burdens. |
| 4928.
 | Comparing cerebral blood flow and cerebrospinal fluid flow during breath-holding and motor tasks in the human brain. JaeGeun Im1, JunHee Kim1, and SungHong Park1
1KAIST, Daejeon, Korea, Republic of Keywords: Neurofluids, Neurofluids Motivation: Recent studies highlight the significant impact of arterial pulsation on CSF movements in animal studies, but direct comparison in awake humans is still limited. Goal(s): This study aims to concurrently measure CSF and CBF, excluding the influence of breathing, to analyze their correlation. Additionally, it investigates changes in CSF movement during the motor task. Approach: Simultaneously measuring CBF and CSF by applying pCASL, and comparing how they change during breath-holding and motor tasks. Results: During breath-holding, we observed a positive correlation between CBF and CSF. Furthermore, we confirmed reduced CSF inflow during the motor task compared to the resting state. Impact: The relationship between CSF movement and CBF was analyzed during
breath-holding and motor tasks in humans for the first time. This study offers
a new way to study CBF and CSF movement, providing a better understanding of CBF-CSF
physiology. |
| 4929.
 | Glymphatic dysfunction in patients with Chronic kidney disease is associated with cognitive decline Lijun Song1, Wenbo Yang1, Mingan Li1, Boyan Xu2, Zhenghan Yang1, Hao Wang1, and Zhen-chang Wang1
1Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China, 2GE HealthCare, MR Research, Beijing, China, Beijing, China Keywords: fMRI Analysis, Kidney, glymphatic system Motivation: The relationship between CSF inflow, which is an essential physiological activity of the glymphatic system, and cognitive decline in patients with chronic kidney disease (CKD) is unclear. Goal(s): Our goal was to explore the patterns of CSF inflow changes in patients with CKD and its relationship with cognitive decline. Approach: The CSF in the the subarachnoid space along the middle cerebral were analyzed with ultra-long echo time and low-b diffusion tensor imaging. Results: Disturbed CSF inflow patterns is associated with cognitive decline in patients with CKD. Impact: A novel approach to measure the CSF inflow of the glymphatic system exhibits the potential for detecting brain glymphatic dysfunction in patients with CKD, which may be one of the pathogenic mechanisms of cognitive decline. |
| 4930.
 | Glymphatic function as a predictor of mild cognitive impairment to dementia conversion in Parkinson’s disease Huize Pang1, Juzhou Wang1, Yueluan Jiang2, and Guoguang Fan1
1the first hospital of China Medical University, Shenyang, China, 2MR Research Collaboration, Siemens Healthineers, Beijing China, Beijing, China Keywords: Diffusion Analysis & Visualization, Diffusion Tensor Imaging, DTI-ALPS Motivation: Impaired glymphatic function is reported to be associated with cognitive function in Parkinson’s disease (PD). However, an evaluation of the role of the glymphatic dysfunction contributing to the dementia conversion of mild cognitive impairment (MCI) with use of MRI remains lacking. Goal(s): To evaluate the value of glymphatic function to predict the dementia conversion in PD with MCI. Approach: We calculated the water diffusion in the periventricular white matter using DTI-ALPS to evaluate the glymphatic function in PD with cognitive impairment during the follow-up. Results: The left DTI-ALPS is significantly lower in dementia converters, and is valuable for prediction of PD dementia conversion. Impact: The
reduction of glymphatic activity, assessed by DTI-ALPS, was more severe in PD
with MCI convert to dementia. Therefore, DTI-ALPS may assist in identifying PD with
MCI at a high risk of dementia conversion before the onset of dementia
symptoms. |
| 4931.
 | Diffusion-weighted imaging-based fluidography for assessing cerebrospinal fluid dynamics in the brains Shunrou Fujiwara1, Kuniaki Ogasawara1, Kohei Chida1, Yosuke Akamatsu1, Takahiro Koji1, Kenya Miyoshi1, Kohki Oikawa1, Jun Yoshida1, Yoshitaka Kubo1, and Yoshichika Yoshioka1
1Iwate Medical University, Yahaba, Japan Keywords: Neurofluids, Brain Motivation: Few study has developed the 3-D image like DTI-tractography to show tendency of CSF dynamic through the whole brain. Goal(s): To develop DWI-fluidography for demonstrating tendency of CSF dynamic through the whole brain. Approach: DWI with multiple b values and MPGs was scanned, and calculated a statistical variation of DWI signals obtained by different MPGs at each b value. The normalized value of the summation of all variations was defined as a value in a voxel for DWI-fluidography. Results: The 3-D DWI-fluidography clearly showed differences of CSF dynamics at anatomical spaces filled with CSF, and the fluidography could reflect quantitative results with ADCs. Impact: The DWI-fluidgraphy has the potential to help us to diagnose/find/investigate CSF-related diseases in the brain. Then, it may open the door to new research area. |