Lydiane Hirschler¹, Bobby A Runderkamp², Suzanne L Franklin^1,3, Thijs van Harten¹, Aart Nederveen², Matthan WA Caan⁴, and Matthias JP van Osch^1
1Leiden University Medical Center, Leiden, Netherlands, ²Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands, ³University Medical Centre Utrecht, Utrecht, Netherlands, ⁴Department of Biomedical Engineering & Physics, Amsterdam University Medical Center, Amsterdam, Netherlands

Recently, flow of cerebrospinal fluid (CSF) has been shown to play an important role in the waste clearance of the brain, ushering in the concepts of glymphatics and intramural periarterial drainage. Despite the importance of brain waste removal, the exact clearance mechanisms such as its driving force are still poorly understood and remain highly controversial. In this study, we image how the cardiac cycle influences the CSF-mobility in the human brain, in the perivascular spaces of the basal ganglia as well as in large CSF-filled spaces, i.e. ventricles and subarachnoid space around large arteries.

Kristina Sonnabend¹, Elena Jäger¹, David Maintz¹, Kilian Weiss^1,2, and Alexander Bunck^1
1University of Cologne, Faculty of Medicine and University Hospital Cologne, Institute for Diagnostic and Interventional Radiology, Cologne, Germany, ²Philips GmbH, Hamburg, Germany

Cerebrospinal fluid (CSF) flow dynamics are relevant parameters in the diagnosis of neurological diseases and can be accessed by three-dimensional time-resolved phase-contrast MRI (4D flow MRI). However, these measurements are accompanied by long scan times making acquisition acceleration necessary to accomplish clinical feasibility. The aim of this study was to evaluate the feasibility of compressed sensing (CS) acceleration in 4D flow MRI of the CSF. CS factors 4 to 10 were compared against the conventional SENSE in 16 healthy subjects. Preliminary results show feasibility of CS factor 6 with comparable image and velocity data quality.

Robert Y Shih^1,2, J Kevin DeMarco^1,2, J Kent Werner^1,2, Justin E Costello^1,2, Isabelle Heukensfeldt Jansen³, Luca Marinelli³, Thomas K Foo³, and Vincent B Ho^1,2
1Uniformed Services University of the Health Sciences, Bethesda, MD, United States, ²Walter Reed National Military Medical Center, Bethesda, MD, United States, ³GE Global Research, Niskayuna, NY, United States

A combination of pressure gradients from arterial pulsatility, respiratory cycles, and resistance changes is thought to drive convective influx of CSF into paraarterial spaces for rapid exchange with ISF, followed by efflux into paravenous spaces toward arachnoid granulations, meningeal lymphatics, or cranial nerves. Visualization of this phenomenon was attempted with peripheral-pulse-gated phase contrast sequences at VENC = 5 mm/s (gradient echo) and 0.24 mm/s (spin echo) in four healthy adults using an ultra-high-performance MAGNUS gradient coil. Very slow intracerebral coherent motion was depicted, cerebropetal during systole, cerebrofugal during diastole, possibly reflecting bulk flow in paravascular spaces of the glymphatic system.
 

Karin Markenroth Bloch¹, Tekla M. Kylkilahti^2,3, Olle Haglund¹, Linn C. Lingehall^2,3, Nils Fregne^2,3, Johannes Töger⁴, and Iben Lundgaard^2,3
1National 7T facility, LBIC, Lund University, Lund, Sweden, ²Department of Experimental Medical Science, Lund University, Lund, Sweden, ³Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden, ⁴Department of Clinical Sciences, Lund University, Lund, Sweden

Little is known about which physiological parameters regulate CSF production. In this work, we tested the hypothesis that cerebral blood flow and heart rate play roles in CSF regulation.  We used 7T MR to quantify CSF flow in the cerebral aqueduct and blood flow in the carotid arteries of healthy volunteers. We found that CSF outflow from the ventricular system correlated with blood flow in the internal carotid arteries, whereas there was no significant effect of heart rate on CSF outflow. This suggests that cerebral blood flow affects CSF flow and production.

Jun-Hee Kim¹ and Sung-Hong Park^1
1Department of Bio and Brain engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea, Republic of

Recent studies showed meningeal lymphatic vessels significantly contribute to the clearance mechanisms of cerebrospinal fluid (CSF) and the immune system in central nervous system. In this study, we tried to image human dural meningeal lymphatic vessels (mLVs) using inversion recovery alternate ascending/descending directional navigation (IR-ALADDIN). The IR-ALADDIN imaging technique clearly showed not only structural dural mLVs, but also the flow direction of dural mLVs, and it can be applied for studying many lymphatic vessels in human neurological diseases.

Fadoua Saadani-Makki^1,2,3, Malek Makki³, Serge Metanbou⁴, Cyrille Capel ⁵, and Olivier Balédent^1,2
1Department of Image Processing, University Hospital, Amiens, France, ²CHIMERE EA 7516, Research Team for Head & Neck, University of Picardie Jules Verne, Amiens, France, ³GIE Faire Face, CHU Amiens Picardie, Amiens, France, ⁴Department of Radiology, University Hospital, Amiens, France, ⁵Department of Neurosurgery, University Hospital, Amiens, France

The aim of this study was to assess the relationship between neuro-fluids dynamic and microstructure architecture of white matter fibers in hydrocephalus patients. Twenty-eight hydrocephalus patients underwent simultaneously diffusion tensor and phase contrast imaging. A statistical correlation between diffusion and flow parameters has shown a biological causal relationship between abnormal brain neuro-fluids dynamic and white matter alterations in hydrocephalus patients.

Lian Li¹, Michael Chopp^1,2, Guangliang Ding¹, Esmaeil Davoodi-Bojd¹, Qingjiang Li¹, Yanlu Zhang¹, Ye Xiong¹, and Quan Jiang^1
1Henry Ford Hospital, Detroit, MI, United States, ²Oakland University, Rochester, MI, United States

Using dynamic MRI glymphatic measurement and our advanced mathematic model, the alterations of glymphatic function in the brain with mild TBI were investigated. Our data show that mild TBI leads to both impaired influx and efflux of contrast agent along the glymphatic pathway. The reduced efficiency of glymphatic function affects the multiple regions across the brain, which may decrease the clearance of waste metabolites and facilitate protein aggregation, contributing to subsequent cognitive deficits. The global change in brain clearance function, rather than the appearance of focal lesions, appears to provide a reliable measure indicating the injury of the brain.

Kristina Sonnabend¹, Gerrit Brinker², David Maintz¹, Alexander Bunck¹, and Kilian Weiss^1,3
1University of Cologne, Faculty of Medicine and University Hospital Cologne, Institute for Diagnostic and Interventional Radiology, Cologne, Germany, ²University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of General Neurosurgery, Center for Neurosurgery, Cologne, Germany, ³Philips GmbH, Hamburg, Germany

Intraspinal compliance is related to neurological diseases and can be measured by pulse wave velocity (PWV). A multiband CINE phase-contrast MRI sequence was developed to measure the intraspinal PWV between two simultaneously acquired slices along spine. The method was evaluated in-vitro, in healthy-subjects and in a normal pressure hydrocephalus patient. In-vitro results show good reproducibility and dependency on transmural pressure in agreement with theory. A higher PWV compared to healthy subjects is observed in the patient. A decline in PWV after shunt surgery is detected, making it a promising tool for investigation and treatment follow-up of neurological diseases.

Liu Jia¹, Cheng Xiaoqing ¹, Lu Guang ming¹, Dou Weiqiang², and Shen Yong^2
1Department of Medical Imaging,, Jinling Hospital , Medical School of Nanjing University, Nanjing, China, ²GE Healthcare, MR Research, Beijing, P.R. China, Nanjing, China

  We aim to investigate the clinial value of 4D flow MRI in assessing cerebrospinal fluid(CSF)dynamics. The optimal velocity encoding factor(VENC) and high test-retest reproducibility was firstly obtained in CSF measurements for healthy volunteers. Ensured by thses, 4D flow MRI has been further applied to evaluate the CSF dynamics for patients with obstructive hydrocephalus before and after endoscopic three ventriculostomy(ETV). Notable cerebrospinal fluid flow at the stoma has been found, indicating that a new cerebrospinal fluid circulation pathway was established. Our study thus demonstrated that 4D flow MRI is an effective tool to assess CSF dynamics quantitively.

Etsuko Kumamoto¹, Shigeto Hayashi^1,2, Ari Shinojima³, Koshi Yokota⁴, and Eiji Kohmura^5
1Kobe University, Kobe, Japan, ²Department of Neurosurgery, Hyogo Emergency Medical Center, Kobe, Japan, ³Keio University, Tokyo, Japan, ⁴Japan Aerospace Exploration Agency, Tsukuba, Japan, ⁵school of medicine, Kobe University, Kobe, Japan

Methodological analysis related to physiological brain shift in the closed cranium is lacking. The spaceflight-associated neuro-ocular syndrome is attributed to the upward shift of the brain. We analyzed the relationship of brain shift and optic nerve shift by using MR volume data acquired in different body positions. The movement and rotation of each voxel, divided into 20 × 20 × 20 pixels³, were calculated using the block matching method. Experimental results show that the optic nerve transforms and deforms with the movement of the brain because of a change in body position.