Quantitative Analysis of Cerebrospinal Fluid Pressure Gradients in Healthy Volunteers and Patients with Normal Pressure Hydrocephalus

Abstract

Magnetic resonance imaging (MRI) can depict not only anatomical information, but also physiological factors such as velocity and pressure gradient. Measurement of these physiological factors is necessary to understand the cerebrospinal fluid (CSF) environment. In this study we quantified CSF motion in various parts of the CSF space, determined changes in the CSF environment with aging, and compared CSF pressure gradient between patients with idiopathic normal pressure hydrocephalus (iNPH) and healthy elderly volunteers. Fifty-seven healthy volunteers and six iNPH patients underwent four-dimensional (4D) phase-contrast (PC) MRI. CSF motion was observed and the pressure gradient of CSF was quantified in the CSF space. In healthy volunteers, inhomogeneous CSF motion was observed whereby the pressure gradient markedly increased in the center of the skull and gradually decreased in the periphery of the skull. For example, the pressure gradient at the ventral surface of the brainstem was 6.6 times greater than that at the convexity of the cerebrum. The pressure gradient was statistically unchanged with aging. The pressure gradient of patients with iNPH was 3.2 times greater than that of healthy volunteers. The quantitative analysis of 4D-PC MRI data revealed that the pressure gradient of CSF can be used to understand the CSF environment, which is not sufficiently given by subjective impression of the anatomical image.

Simple Identification of Cerebrospinal Fluid Turbulent Motion Using a Dynamic Improved Motion-sensitized Driven-equilibrium Steady-state Free Precession Method Applied to Various Types of Cerebrospinal Fluid Motion Disturbance

“…1,17) Moreover, it has been found that CSF motion is augmented and becomes turbulent in the subarachnoid space at the ventral surface of the brainstem and third ventricle. 2,18) The reason of increased turbulent CSF motion at the ventral surface of the brainstem was explained that…”

“…Each imaging method has its own features. Because several reports show that CSF motion is strong and turbulent in the subarachnoid space of the ventral surface of the brainstem, 1,2,17,27) when ETV is performed in patients with ventricular dilatation with suppressed CSF motion, changes in ETV fenestration can be visualized clearly as turbulence with the Dynamic iMSDE SSFP method. In addition, an extensive improvement in the suppressed CSF motion can be observed through better communication between the subarachnoid space of the ventral surface of the brainstem and third ventricle after ETV, demonstrating its superiority for postoperative imaging evaluation.…”

“…1) Moreover, some areas present increased acceleration, and others show attenuated acceleration, indicating the unevenness of CSF even within the cranial cavity. 2) In such areas that present with increased acceleration, the water molecule movement often becomes turbulent due to the relationship with the surrounding structures; this turbulence cannot be properly captured or followed even with tracer infusion into the CSF. In addition to accelerating and becoming turbulent like this in certain spaces, it is also known that when, for example, the movement of water molecules propagates through a narrow stoma between two cavities, water molecules move more aggressively at this time, and when fluid propagates to another cavity, it becomes turbulent.…”

Accuracy of 4D Flow Measurement of Cerebrospinal Fluid Dynamics in the Cervical Spine: An In Vitro Verification Against Numerical Simulation

“…Quantitative assessment of CSF dynamics is thought to be important because of its potential application to help characterize CNS disorders such as Chiari malformation 5, 6, 10 , predict CSF pressure gradients 13 and predict intrathecal drug distribution 17 . In vivo 4D Flow assessment of CSF hydrodynamics is desirable because all velocity components can be directly obtained; whereas, MRI-based CFD techniques require a number of assumptions and simplifications.…”

Comparison of 3 and 7 Tesla Magnetic Resonance Imaging of Obstructive Hydrocephalus Caused by Tectal Glioma

“…However, recent surgical technology can provide both quantitative and qualitative information [1415]. Furthermore, phase-contrast 7T MRI improves the detail in which anatomical changes in the periventricular region and hemodynamic changes can be visualized.…”