Detection of a relation between respiration and CSF pulsation with an echoplanar technique

Abstract

The flow of cerebrospinal fluid (CSF) through the aqueduct was studied with an echoplanar imaging technique. Images (1024) of a slice perpendicular to the aqueduct were acquired with a repetition time of 107 msec and a flip angle of 90°. This imaging technique is very sensitive for flow into the selected slice, although a quantitative assessment of flow velocities is not possible. Simultaneously with the image data acquisition, data from a pulse oximeter and a respiration belt were recorded. For each data point, a delay time to the preceding cardiac pulse was determined from the recorded pulse wave. The signal intensities could then be assigned to the cardiac cycle. Each cardiac interval was assigned to one of eight respiratory phases, and an average signal curve during the cardiac interval was calculated for each respiration phase. The evaluation showed to signal maxima within the cardiac interval, which could be identified as a downward flow at 10% and an upward flow at 80% of the cardiac pulse interval by measurements with additional saturation pulses. In examinations of 22 healthy volunteers, an influence of respiration on the flow through the aqueduct was found. In spite of interindividual variability, comparable effects could be observed in all volunteers. In the late expiration phase the caudally directed flow was at its maximum, whereas the cranially directed flow was maximal in the post‐inspiration phase. J. Magn. Reson. Imaging 2000;11:438–444. © 2000 Wiley‐Liss, Inc.

Identification of the Upward Movement of Human CSFIn Vivoand its Relation to the Brain Venous System

“…This concept is physically plausible, as was suggested previously (Klose et al, 2000;Friese et al, 2004). In view of the instantaneous albeit opposite responses to inspiration, the present results support the notion of a closely communicating and interdependent CSF-venous system.…”

“…sensitive MRI sequences, only very few studies avoided cardiac synchronization to evaluate the effects of respiration on CSF dynamics using echoplanar imaging (Klose et al, 2000;Friese et al, 2004) or respiration-induced spin labeling (Yamada et al, 2013). A more recent study used real-time phase-contrast flow MRI based on echoplanar imaging to evaluate the effect of different breathing maneuvers (Chen et al, 2015).…”

False activation in the brain ventricles related to task-correlated breathing in fMRI speech and motor paradigms

“…Another explanation may involve movement of CSF fluid in the brain ventricles. CSF pulsates in and out of the brain and spinal canal in direct relation to the cardiac cycle and respiration-induced pressure fluctuations, causing a signal change [30]. Klose et al [30] reported that maximal caudally directed CSF flow was found in late expiration, whereas maximal cranially directed flow was found immediately post-inspiration, and flow in either direction led to an enhanced signal.…”

Time‐resolved three‐dimensional (3D) phase‐contrast (PC) balanced steady‐state free precession (bSSFP)

“…Our results showed that there are nonnegligible in-plane velocity components within a transversal imaging slab, information not provided by earlier works using PC bSSFP for 2D, throughplane flow quantification of the CSF (10). This additional information might improve the understanding of the physiology of CSF circulation, both inside the brain and in the spine, and to validate the current hypotheses existing in the literature (10,21,29,30).…”