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Real-time imaging of respiratory effects on cerebrospinal fluid flow in small diameter passageways

Töger, Johannes LU ; Andersen, Mads LU ; Haglund, Olle ; Kylkilahti, Tekla Maria LU ; Lundgaard, Iben LU and Markenroth Bloch, Karin LU orcid (2022) In Magnetic Resonance in Medicine 88(2). p.770-786
Abstract

Purpose: Respiration-related CSF flow through the cerebral aqueduct may be useful for elucidating physiology and pathophysiology of the glymphatic system, which has been proposed as a mechanism of brain waste clearance. Therefore, we aimed to (1) develop a real-time (CSF) flow imaging method with high spatial and sufficient temporal resolution to capture respiratory effects, (2) validate the method in a phantom setup and numerical simulations, and (3) apply the method in vivo and quantify its repeatability and correlation with different respiratory conditions. Methods: A golden-angle radial flow sequence (reconstructed temporal resolution 168 ms, spatial resolution 0.6 mm) was implemented on a 7T MRI scanner and reconstructed using... (More)

Purpose: Respiration-related CSF flow through the cerebral aqueduct may be useful for elucidating physiology and pathophysiology of the glymphatic system, which has been proposed as a mechanism of brain waste clearance. Therefore, we aimed to (1) develop a real-time (CSF) flow imaging method with high spatial and sufficient temporal resolution to capture respiratory effects, (2) validate the method in a phantom setup and numerical simulations, and (3) apply the method in vivo and quantify its repeatability and correlation with different respiratory conditions. Methods: A golden-angle radial flow sequence (reconstructed temporal resolution 168 ms, spatial resolution 0.6 mm) was implemented on a 7T MRI scanner and reconstructed using compressed sensing. A phantom setup mimicked simultaneous cardiac and respiratory flow oscillations. The effect of temporal resolution and vessel diameter was investigated numerically. Healthy volunteers (n = 10) were scanned at four different respiratory conditions, including repeat scans. Results: Phantom data show that the developed sequence accurately quantifies respiratory oscillations (ratio real-time/reference QR = 0.96 ± 0.02), but underestimates the rapid cardiac oscillations (ratio QC = 0.46 ± 0.14). Simulations suggest that QC can be improved by increasing temporal resolution. In vivo repeatability was moderate to very strong for cranial and caudal flow (intraclass correlation coefficient range: 0.55–0.99) and weak to strong for net flow (intraclass correlation coefficient range: 0.48–0.90). Net flow was influenced by respiratory condition (p < 0.01). Conclusions: The presented real-time flow MRI method can quantify respiratory-related variations of CSF flow in the cerebral aqueduct, but it underestimates rapid cardiac oscillations. In vivo, the method showed good repeatability and a relationship between flow and respiration.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
cerebrospinal fluid, CSF, flow, magnetic resonance imaging, MRI, real-time
in
Magnetic Resonance in Medicine
volume
88
issue
2
pages
17 pages
publisher
John Wiley & Sons Inc.
external identifiers
  • scopus:85127771975
  • pmid:35403247
ISSN
0740-3194
DOI
10.1002/mrm.29248
language
English
LU publication?
yes
id
74d6c3ee-ad78-4130-b0f8-dd98bcb4f2ea
date added to LUP
2022-06-28 13:43:25
date last changed
2024-09-18 14:48:23
@article{74d6c3ee-ad78-4130-b0f8-dd98bcb4f2ea,
  abstract     = {{<p>Purpose: Respiration-related CSF flow through the cerebral aqueduct may be useful for elucidating physiology and pathophysiology of the glymphatic system, which has been proposed as a mechanism of brain waste clearance. Therefore, we aimed to (1) develop a real-time (CSF) flow imaging method with high spatial and sufficient temporal resolution to capture respiratory effects, (2) validate the method in a phantom setup and numerical simulations, and (3) apply the method in vivo and quantify its repeatability and correlation with different respiratory conditions. Methods: A golden-angle radial flow sequence (reconstructed temporal resolution 168 ms, spatial resolution 0.6 mm) was implemented on a 7T MRI scanner and reconstructed using compressed sensing. A phantom setup mimicked simultaneous cardiac and respiratory flow oscillations. The effect of temporal resolution and vessel diameter was investigated numerically. Healthy volunteers (n = 10) were scanned at four different respiratory conditions, including repeat scans. Results: Phantom data show that the developed sequence accurately quantifies respiratory oscillations (ratio real-time/reference Q<sub>R</sub> = 0.96 ± 0.02), but underestimates the rapid cardiac oscillations (ratio Q<sub>C</sub> = 0.46 ± 0.14). Simulations suggest that Q<sub>C</sub> can be improved by increasing temporal resolution. In vivo repeatability was moderate to very strong for cranial and caudal flow (intraclass correlation coefficient range: 0.55–0.99) and weak to strong for net flow (intraclass correlation coefficient range: 0.48–0.90). Net flow was influenced by respiratory condition (p &lt; 0.01). Conclusions: The presented real-time flow MRI method can quantify respiratory-related variations of CSF flow in the cerebral aqueduct, but it underestimates rapid cardiac oscillations. In vivo, the method showed good repeatability and a relationship between flow and respiration.</p>}},
  author       = {{Töger, Johannes and Andersen, Mads and Haglund, Olle and Kylkilahti, Tekla Maria and Lundgaard, Iben and Markenroth Bloch, Karin}},
  issn         = {{0740-3194}},
  keywords     = {{cerebrospinal fluid; CSF; flow; magnetic resonance imaging; MRI; real-time}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{770--786}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Magnetic Resonance in Medicine}},
  title        = {{Real-time imaging of respiratory effects on cerebrospinal fluid flow in small diameter passageways}},
  url          = {{http://dx.doi.org/10.1002/mrm.29248}},
  doi          = {{10.1002/mrm.29248}},
  volume       = {{88}},
  year         = {{2022}},
}