| 08:15 | | IntroductionClaudia Gandini Wheeler-Kingshott UCL Institute of Neurology, United Kingdom |
| 08:27 | 0796.
 | Characterizing blood and cerebrospinal fluid flow by D* tensor derived from intravoxel-incoherent-motion-diffusion-tensor-imaging Paulien Voorter1,2, Gerald Drenthen1,2, Merel van der Thiel1,2,3, Julie Staals4,5, Oliver Gurney-Champion6,7, Alida Postma1,2, Robert van Oostenbrugge2,4,5, Jacobus Jansen1,2,8, and Walter Backes1,2,5
1Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands, 2School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands, 3Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, Netherlands, 4Department of Neurology, Maastricht University Medical Center, Maastricht, Netherlands, 5School for Cardiovascular Disease, Maastricht University, Maastricht, Netherlands, 6Department of Radiology and Nuclear Imaging, Amsterdam UMC location University of Amsterdam, Amsterdam, Netherlands, 7Imaging and Biomarkers, Cancer Center Amsterdam, Amsterdam, Netherlands, 8Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands Keywords: IVIM, Diffusion/other diffusion imaging techniques Motivation: A deeper understanding of brain physiology and pathology can be provided with an intravoxel-incoherent-motion-diffusion-tensor-imaging (IVIM-DTI) MR scan, which simultaneously measures blood and cerebrospinal fluid (CSF) flow and flow directions; parenchymal anisotropy; and microvascular perfusion. Goal(s): To demonstrate the feasibility of IVIM-DTI to provide a proxy for blood and CSF flow. Approach: A tensor of the pseudo-diffusion component (D*) was derived from IVIM-DTI and related to arterial and ventricular physiology. Results: D* ellipsoids align well with arterial blood and CSF flow. D*’s magnitude and anisotropy correspond to the expected flow in arteries and ventricles, indicating the technique's ability of characterizing flow dynamics. Impact: Assessing blood
and cerebrospinal fluid flow with intravoxel-incoherent-motion-diffusion-tensor-imaging
(IVIM-DTI) alongside traditional IVIM and DTI measures can provide comprehensive
pathophysiological insights into neurological conditions. The finding that
these physiological processes contribute to IVIM-derived f and D*
is important for their interpretation. |
| 08:39 | 0797.
 | Exploring radial asymmetry in MR diffusion tensor imaging and its impact on the interpretation of glymphatic mechanisms Adam M Wright1,2, Yu-Chien Wu2,3, Nan-Kuei Chen4, and Qiuting Wen2
1Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 2Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States, 3Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States, 4Department of Biomedical Engineering, University of Arizona, Tucson, AZ, United States Keywords: Neurofluids, Neurofluids Motivation: Researchers have used diffusion tensor imaging along the perivascular space (DTI-ALPS) to investigate glymphatic function, but the influence of white matter properties on the ALPS-index remains unstudied. Goal(s): Establish whether a reduction in the ALPS-index could be influenced by axonal changes. Approach: A key assumption underlying the ALPS-index is that axons demonstrate symmetric radial diffusivities, such that eigenvalue-2 and eigenvalue-3 are equal (λ2=λ3). We investigated this assumption and evaluated λ2/λ3 changes in white matter tracts. Results: Contrary to the DTI-ALPS assumption, widespread radial asymmetry (λ2/λ3≈1.5) was observed within all white matter tracts, the extent of which decreased with aging and neurodegeneration. Impact: This study unveils widespread radial asymmetry of white matter tracts — a phenomenon that has been overlooked in DTI studies. The results provide evidence of axonal contributions to the ALPS-index, prompting researchers to consider axonal influences when interpreting this metric. |
| 08:51 | 0798.
 | Investigation of Feasibility of Measurement of Neurofluid Movement by Propagator Analysis based on Q-space Imaging Satoshi Yatsushiro1,2, Keita Murayama3, Hideki Atsumi4, Tomohiko Horie5, and Kagayaki Kuroda1,3
1Human and Information Science, Tokai University, Kanagawa, Japan, 2BioView, Inc., Tokyo, Japan, 3Course of Electrical and Electronic Engineering, Tokai University, Kanagawa, Japan, 4Department of Neursurgery, School of Medicine, Tokai University, Kanagawa, Japan, 5Department of Radiological Technology, Tokai University Hospital, Kanagawa, Japan Keywords: Neurofluids, Neurofluids Motivation: To quantitatively measure neurofluid movement in the brain parenchyma of mouse and human by propagator analysis of q-space imaging (QSI). Goal(s): The accuracy of the propagator analysis to measure the neurofluid movement including the pulsation and the blood flow was investigated by Bloch simulation. Approach: The propagator analysis of pulsatile neurofluid or capillary blood flow in a voxel was conducted by Bloch simulation. The accuracy of the technique in the constant flow was validated by experiments. Results: The propagator analysis indicated the high accuracy of the velocity measurement of the pulsatile neurofluid movement and the blood flow. Impact: The high accuracy of the velocity measurement of QSI-based propagator analysis of pulsatile movement and blood flow in the voxel was validated by Bloch simulation. The technique may reveal neurofluid movement and clearance mechanism of neurowastes in human brain. |
| 09:03 | 0799.
 | Optimization of Simultaneous Coherent/Incoherent Motion Imaging (SCIMI): Combined Diffusion and Velocimetry for Glymphatic Circulation Isabelle Heukensfeldt Jansen1, Nastaren Abad1, Afis Ajala1, J Kevin DeMarco2,3, H. Doug Morris2, Vincent B Ho2,3, Kent Werner2, Angeliki Pollatou2, Gail Kohls3, Haymanot Yalewayker2, Maureen Hood2,3, Sonja Skeete2,3, Elizabeth Metzger2,3, Robert Shih2,3, Thomas K.F. Foo1, and Luca Marinelli1
1GEHC Technology and Innovation Center, Niskayuna, NY, United States, 2Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 3Walter Reed National Military Medical Center, Bethesda, MD, United States Keywords: Neurofluids, Neurofluids, Glymphatic, MRI Velocimetry, Phase-Sensitive Diffusion Motivation: To study glymphatic circulation in the brain parenchymal tissue, methods to measure sub-millimeter velocities of fluid flow in tissue must be developed.
Goal(s): We evaluate the feasibility of imaging both coherent and incoherent motion (SCIMI) in brain tissue using phase-sensitive reconstruction of dMRI. Approach: Approach: By modifying a DTI sequence to achieve physiologically relevant low VENC, we demonstrate the simultaneous reconstruction of diffusion metrics highlighting incoherent motion in the brain and velocity data showing coherent motion by leveraging phase and magnitude information. Results: We measure velocity maps in the whole brain in conjunction with clinically relevant diffusion metrics. Impact: SCIMI acquisition and reconstruction of velocity in brain parenchymal
tissue shows to be an important addendum that can be run parallel to existing
DTI methods and provides novel insights into glymphatic circulation. |
| 09:15 | 0800.
 | Dynamics of Respiratory Motion in Slow Flow Measurement using Simultaneous Coherent and Incoherent Motion Imaging Method Afis Ajala1, Isabelle Heukensfeldt Jansen1, Seung-Kyun Lee1, Nastaren Abad1, Thomas KF Foo1, J Kevin DeMarco2,3, Robert Y Shih2,3, Gail Kohls3, H Doug Morris2, Angeliki Pollatou2, Haymanot Yalewayker2, Maureen N Hood2,3, Sonja Skeete2,3, Elizabeth Metzger2,3, Vincent B Ho2,3, J Kent Werner2, and Luca Marinelli1
1GE HealthCare, Niskayuna, NY, United States, 2Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 3Walter Reed National Military Medical Center, Bethesda, MD, United States Keywords: Neurofluids, Neurofluids Motivation: The impact of respiration on fluid flow in brain parenchyma is poorly understood and remains an on-going research topic in MRI velocimetry. Goal(s): To analyze the sensitivity of the simultaneous coherent and incoherent motion imaging (SCIMI) method to respiratory-induced phase in the brain parenchyma and to regress this phase contribution from the underlying slow-flow-induced phase. Approach: Prospectively cardiac-gated SCIMI acquisitions were obtained during three different breathing schemes. Results: Existence of strong correlations (p<0.005) between the breathing profiles and measured phase in various brain regions indicated the presence of respiration-induced phase in the SCIMI acquisition, and regression of such phases showed promising results. Impact: This study showed the sensitivity
of simultaneous coherent and incoherent motion imaging method to respiration-induced
phase in the brain, and an initial attempt to regress such phase accrual from the
desired brain slow flows$$$–$$$an important biomarker of glymphatic function. |
| 09:27 | 0801.
 | Brain Clearance Assessment Using the DTI-ALPS Index and Intrathecal Contrast Enhanced Magnetic Resonance Imaging Ingrid Mossige1,2, Tryggve Holck Storås1, Kyrre Eeg Emblem1, Per Kristian Eide2,3, and Geir André Ringstad4
1Division of Radiology and Nuclear Medicine, Department of Physics and Computational Radiology, Oslo University Hospital, Oslo, Norway, 2Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway, 3Department of Neurosurgery, Oslo University Hospital-Rikshospitalet, Oslo, Norway, 4Department of Radiology, Oslo University Hospital-Rikshospitalet, Oslo, Norway Keywords: Neurofluids, Neurofluids Motivation: To investigate if DTI-ALPS as a non-invasive method compared to intrathecal contrast enhanced magnetic resonance (gMRI) imaging can be used for evaluating human brain clearance function. Goal(s): To investigate whether or not DTI-ALPS can be used as a non-invasive alternative to gMRI. Approach: This study compared the ALPS index with brain clearance parameters derived from gMRI in a reference group (REF). Results: No significant relationships were found between the ALPS index and change in normalized T1w signal intensity from the gMRI data in both the distribution phase and clearance phase. Impact: The proposed DTI-ALPS index may not be a valid
marker of glymphatic function. |
| 09:39 | 0802.
 | Locus Coeruleus Influence on Cognitive Function via the Glymphatic System in Parkinson's Disease Xinhui Wang1, Ewart Mark Haacke2,3, Naying He4, Yu Liu4, Peng Wu5, and Fuhua Yan3,6
1Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, 2Wayne State University, Detroit, MI, United States, 3Radiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China, 4Shanghai Jiao Tong University School of Medicine, Shanghai, China, 5Philips Healthcare, Shanghai, China, 6College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, Shanghai, China Keywords: Parkinson's Disease, Parkinson's Disease Motivation: The underlying mechanism of locus coeruleus (LC) in cognitive function of Parkinson’s disease (PD) has not been clearly elucidated. Goal(s): To investigate the relationship among LC degeneration, cognitive function, and the glymphatic system in PD. Approach: All participants underwent neuromelanin-sensitive magnetic resonance imaging (NM-MRI) and diffusion tensor image scanning. The whole brain glymphatic activity was measured using diffusion along the perivascular space (ALPS) index, while LC degeneration was estimated using the NM contrast-to-noise ratio of LC (CNRLC). Results: Mediation analysis demonstrated that the ALPS index acted as a significant mediator between CNRLC and the MoCA score in PD subjects. Impact: These
findings enhance our grasp of how the LC noradrenergic system influences
cognitive function through the glymphatic system. This research offers a
promising starting point for exploring potential therapies and further research
into cognitive impairment in Parkinson's disease. |
| 09:51 | 0803.
 | Human Umbilical Cord Blood-Mononuclear Cell Transplantation Improves Glymphatic System Activity in Patients with Multiple System Atrophy Chuanying Shi1, Dianrong Gong2, Peng Wu3, Xiance Zhao3, and Peiji Song4
1Department of radiology, Liaocheng People’s Hospital, Liaocheng, China, 2Department of neurology, Liaocheng People’s Hospital, Liaocheng, China, 3Philips Healthcare, Shanghai, China, 4Department of radiology, Jinan Central Hospital, Jinan, China Keywords: Parkinson's Disease, Parkinson's Disease, Diffusion tensor image Motivation: Glymhatic system as a therapeutic target for multiple system atrophy (MSA) lacks imaging markers. Goal(s): Our goal was to determine changes in imaging parameters after human umbilical cord blood mononuclear cells (hUCB-MCs) transplantation. Approach: Diffusion tensor image analysis along the perivascular space (DTI-ALPS) of MSA patients were compared with healthy controls and the ALPS indices of patients were compared before and after hUCB-MCs transplantation. Results: We found that MSA patients had lower ALPS values than health controls and that ALPS values increased after treatment. Impact: Our demonstration of a detectable decline in MSA patients and an uptick after treatment utilizing ALPS metrics provides an imaging marker to monitor the glymphatic system after hUCB-MCs transplantation. |
| 10:03 | 0804.
 | Aberrant interstitial fluids may be associated with cognitive impairment in patients on chronic kidney disease Wenbo Yang1, Lijun Song1, Mingan Li1, Boyan Xu2, Zhenghan Yang1, Hao Wang1, and Zhen-chang Wang1
1Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China, 2MR Research, GE Healthcare, Beijing, China Keywords: Neurofluids, Neurofluids Motivation: Chronic kidney disease (CKD) leads to cognitive impairment; however, the pathophysiology remains unclear. Goal(s): This study aims to evaluate differences in interstitial fluids (ISF) between patients with CKD and healthy controls, and investigate correlation between ISF circulation with cognitive impairment. Approach: Spectral diffusion analysis was applied to measure the ISF fraction (fint). Results: A significant difference in fint was detected between the HD and HC groups in the right basa gangliaand biliteral centrum semiovale(CSO). In the CKD group, MoCA scores were negatively correlated with fint in the biliteral CSO. Impact: A novel approach to measure ISF exhibits the potential for detecting brain glymphatic dysfunction in patients with CKD, which provides unique insights into the pathological mechanisms of patients on CKD with cognitive impairment. |