Improved cerebrospinal fluid flow measurements using phase contrast balanced steady-state free precession

Erin J. McCormack, Michael R. Egnor, Mark E. Wagshul

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

We present a demonstration of phase contrast balanced steady-state free precession (PC-bSSFP) for measuring cerebrospinal fluid (CSF) flow in the brain and spine, and a comparison of measurements obtained with this technique to conventional phase contrast using incoherent gradient echoes (PC-GRE). With PC-GRE sequences, CSF images suffer from low signal-to-noise ratio (SNR), due to short repetition times required for adequate temporal resolution, and the long relaxation time of CSF. Furthermore, CSF flow is often nonlaminar, causing phase dispersion and signal loss in PC-GRE images. It is hypothesized that PC-bSSFP can improve CSF flow measurements with its high SNR and insensitivity to turbulent flow effects. CSF images acquired from the two techniques were compared in 13 healthy volunteers. Three measures were used to objectively evaluate the PC-bSSFP sequence: the CSF flow percentage, defined as the percentage of the total CSF region exhibiting pulsatile flow, net stroke volume and SNR. Images acquired with PC-bSSFP demonstrated pulsatile CSF flow in 35.8% (P<.005), 11.2% (P<.05) and 27.8% (P<.0005) more pixels than PC-GRE in the prepontine cistern, anterior and posterior cervical subarachnoid space (SAS), respectively. Likewise, measurements of stroke volume in these regions increased by 61.6% (P<.05), 16.8% (P<.001) and 48.3% (P<.0001), respectively. Similar comparisons in the aqueduct showed no statistical difference in stroke volumes between the two techniques (P=.5). The average gain in SNR was 3.3±1.7 (P<.001) in the prepontine cistern, 5.0±0.2 (P<.01) at the cervical level and 2.0±0.4 (P<.001) in the aqueduct in PC-bSSFP magnitude images over PC-GRE images. In addition to the obvious advantage of increased SNR, these results indicate that PC-bSSFP provides more complete measurements of CSF flow data than PC-GRE. PC-bSSFP can be used as a reliable technique for CSF flow quantification for the characterization of normal and altered intracranial CSF flow patterns.

Original languageEnglish (US)
Pages (from-to)172-182
Number of pages11
JournalMagnetic Resonance Imaging
Volume25
Issue number2
DOIs
StatePublished - Feb 2007
Externally publishedYes

Fingerprint

cerebrospinal fluid
Cerebrospinal fluid
flow measurement
phase contrast
Flow measurement
precession
fluid flow
Cerebrospinal Fluid
Flow of fluids
Signal-To-Noise Ratio
echoes
stroke volume
Signal to noise ratio
signal to noise ratios
gradients
Stroke Volume
flow nets
Pulsatile Flow
Pulsatile flow
Subarachnoid Space

Keywords

  • Cerebrospinal fluid (CSF)
  • CSF flow
  • Hydrocephalus
  • Phase contrast
  • Steady-state free precession (SSFP)

ASJC Scopus subject areas

  • Biophysics
  • Clinical Biochemistry
  • Structural Biology
  • Radiology Nuclear Medicine and imaging
  • Condensed Matter Physics

Cite this

Improved cerebrospinal fluid flow measurements using phase contrast balanced steady-state free precession. / McCormack, Erin J.; Egnor, Michael R.; Wagshul, Mark E.

In: Magnetic Resonance Imaging, Vol. 25, No. 2, 02.2007, p. 172-182.

Research output: Contribution to journalArticle

@article{d43cc4a721f14c29833a292fdc018b00,
title = "Improved cerebrospinal fluid flow measurements using phase contrast balanced steady-state free precession",
abstract = "We present a demonstration of phase contrast balanced steady-state free precession (PC-bSSFP) for measuring cerebrospinal fluid (CSF) flow in the brain and spine, and a comparison of measurements obtained with this technique to conventional phase contrast using incoherent gradient echoes (PC-GRE). With PC-GRE sequences, CSF images suffer from low signal-to-noise ratio (SNR), due to short repetition times required for adequate temporal resolution, and the long relaxation time of CSF. Furthermore, CSF flow is often nonlaminar, causing phase dispersion and signal loss in PC-GRE images. It is hypothesized that PC-bSSFP can improve CSF flow measurements with its high SNR and insensitivity to turbulent flow effects. CSF images acquired from the two techniques were compared in 13 healthy volunteers. Three measures were used to objectively evaluate the PC-bSSFP sequence: the CSF flow percentage, defined as the percentage of the total CSF region exhibiting pulsatile flow, net stroke volume and SNR. Images acquired with PC-bSSFP demonstrated pulsatile CSF flow in 35.8{\%} (P<.005), 11.2{\%} (P<.05) and 27.8{\%} (P<.0005) more pixels than PC-GRE in the prepontine cistern, anterior and posterior cervical subarachnoid space (SAS), respectively. Likewise, measurements of stroke volume in these regions increased by 61.6{\%} (P<.05), 16.8{\%} (P<.001) and 48.3{\%} (P<.0001), respectively. Similar comparisons in the aqueduct showed no statistical difference in stroke volumes between the two techniques (P=.5). The average gain in SNR was 3.3±1.7 (P<.001) in the prepontine cistern, 5.0±0.2 (P<.01) at the cervical level and 2.0±0.4 (P<.001) in the aqueduct in PC-bSSFP magnitude images over PC-GRE images. In addition to the obvious advantage of increased SNR, these results indicate that PC-bSSFP provides more complete measurements of CSF flow data than PC-GRE. PC-bSSFP can be used as a reliable technique for CSF flow quantification for the characterization of normal and altered intracranial CSF flow patterns.",
keywords = "Cerebrospinal fluid (CSF), CSF flow, Hydrocephalus, Phase contrast, Steady-state free precession (SSFP)",
author = "McCormack, {Erin J.} and Egnor, {Michael R.} and Wagshul, {Mark E.}",
year = "2007",
month = "2",
doi = "10.1016/j.mri.2006.09.023",
language = "English (US)",
volume = "25",
pages = "172--182",
journal = "Magnetic Resonance Imaging",
issn = "0730-725X",
publisher = "Elsevier Inc.",
number = "2",

}

TY - JOUR

T1 - Improved cerebrospinal fluid flow measurements using phase contrast balanced steady-state free precession

AU - McCormack, Erin J.

AU - Egnor, Michael R.

AU - Wagshul, Mark E.

PY - 2007/2

Y1 - 2007/2

N2 - We present a demonstration of phase contrast balanced steady-state free precession (PC-bSSFP) for measuring cerebrospinal fluid (CSF) flow in the brain and spine, and a comparison of measurements obtained with this technique to conventional phase contrast using incoherent gradient echoes (PC-GRE). With PC-GRE sequences, CSF images suffer from low signal-to-noise ratio (SNR), due to short repetition times required for adequate temporal resolution, and the long relaxation time of CSF. Furthermore, CSF flow is often nonlaminar, causing phase dispersion and signal loss in PC-GRE images. It is hypothesized that PC-bSSFP can improve CSF flow measurements with its high SNR and insensitivity to turbulent flow effects. CSF images acquired from the two techniques were compared in 13 healthy volunteers. Three measures were used to objectively evaluate the PC-bSSFP sequence: the CSF flow percentage, defined as the percentage of the total CSF region exhibiting pulsatile flow, net stroke volume and SNR. Images acquired with PC-bSSFP demonstrated pulsatile CSF flow in 35.8% (P<.005), 11.2% (P<.05) and 27.8% (P<.0005) more pixels than PC-GRE in the prepontine cistern, anterior and posterior cervical subarachnoid space (SAS), respectively. Likewise, measurements of stroke volume in these regions increased by 61.6% (P<.05), 16.8% (P<.001) and 48.3% (P<.0001), respectively. Similar comparisons in the aqueduct showed no statistical difference in stroke volumes between the two techniques (P=.5). The average gain in SNR was 3.3±1.7 (P<.001) in the prepontine cistern, 5.0±0.2 (P<.01) at the cervical level and 2.0±0.4 (P<.001) in the aqueduct in PC-bSSFP magnitude images over PC-GRE images. In addition to the obvious advantage of increased SNR, these results indicate that PC-bSSFP provides more complete measurements of CSF flow data than PC-GRE. PC-bSSFP can be used as a reliable technique for CSF flow quantification for the characterization of normal and altered intracranial CSF flow patterns.

AB - We present a demonstration of phase contrast balanced steady-state free precession (PC-bSSFP) for measuring cerebrospinal fluid (CSF) flow in the brain and spine, and a comparison of measurements obtained with this technique to conventional phase contrast using incoherent gradient echoes (PC-GRE). With PC-GRE sequences, CSF images suffer from low signal-to-noise ratio (SNR), due to short repetition times required for adequate temporal resolution, and the long relaxation time of CSF. Furthermore, CSF flow is often nonlaminar, causing phase dispersion and signal loss in PC-GRE images. It is hypothesized that PC-bSSFP can improve CSF flow measurements with its high SNR and insensitivity to turbulent flow effects. CSF images acquired from the two techniques were compared in 13 healthy volunteers. Three measures were used to objectively evaluate the PC-bSSFP sequence: the CSF flow percentage, defined as the percentage of the total CSF region exhibiting pulsatile flow, net stroke volume and SNR. Images acquired with PC-bSSFP demonstrated pulsatile CSF flow in 35.8% (P<.005), 11.2% (P<.05) and 27.8% (P<.0005) more pixels than PC-GRE in the prepontine cistern, anterior and posterior cervical subarachnoid space (SAS), respectively. Likewise, measurements of stroke volume in these regions increased by 61.6% (P<.05), 16.8% (P<.001) and 48.3% (P<.0001), respectively. Similar comparisons in the aqueduct showed no statistical difference in stroke volumes between the two techniques (P=.5). The average gain in SNR was 3.3±1.7 (P<.001) in the prepontine cistern, 5.0±0.2 (P<.01) at the cervical level and 2.0±0.4 (P<.001) in the aqueduct in PC-bSSFP magnitude images over PC-GRE images. In addition to the obvious advantage of increased SNR, these results indicate that PC-bSSFP provides more complete measurements of CSF flow data than PC-GRE. PC-bSSFP can be used as a reliable technique for CSF flow quantification for the characterization of normal and altered intracranial CSF flow patterns.

KW - Cerebrospinal fluid (CSF)

KW - CSF flow

KW - Hydrocephalus

KW - Phase contrast

KW - Steady-state free precession (SSFP)

UR - http://www.scopus.com/inward/record.url?scp=33846493568&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33846493568&partnerID=8YFLogxK

U2 - 10.1016/j.mri.2006.09.023

DO - 10.1016/j.mri.2006.09.023

M3 - Article

C2 - 17275611

AN - SCOPUS:33846493568

VL - 25

SP - 172

EP - 182

JO - Magnetic Resonance Imaging

JF - Magnetic Resonance Imaging

SN - 0730-725X

IS - 2

ER -