title: Influence of respiration on cerebrospinal fluid movement using magnetic resonance spin labeling.
abstract: BACKGROUND
  Magnetic resonance imaging (MRI) cardiac gated phase contrast (PC) cine techniques have non-invasively shown the effect of the cardiac pulse on cerebrospinal fluid (CSF) movement. Echo planar imaging (EPI) has shown CSF movement as influenced by both cardiac pulsation and respiration. Previously, it has not been possible to visualize CSF movement in response to respiration non-invasively. The present study was undertaken to do so.
  
  
  METHODS
  The effect of respiration on CSF movement was investigated using a non-contrast time-spatial labeling inversion pulse (Time-SLIP) with balanced steady-state free precession (bSSFP) readout. CSF movement was observed in the intracranial compartment in response to respirations in ten normal volunteers. To elucidate the respiration effect, the acquisition was triggered at the beginning of deep inhalation, deep exhalation and breath holding.
  
  
  RESULTS
  By employing this respiration-induced spin labeling bSSFP cine method, we were able to visualize CSF movement induced by respiratory excursions. CSF moved cephalad (16.4 ± 7.7 mm) during deep inhalation and caudad (11.6 ± 3.0 mm) during deep exhalation in the prepontine cisternal area. Small but rapid cephalad (3.0 ± 0.4 mm) and caudad (3.0 ± 0.5 mm) movement was observed in the same region during breath holding and is thought to reflect cardiac pulsations.
  
  
  CONCLUSIONS
  The Time-SLIP bSSFP cine technique allows for non-invasive visualization of CSF movement associated with respiration to a degree not previously reported.
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Toshiba Medical Research Institute USA, Inc,, 706 N, Deerpath Drive, Vernon Hills, Illinois 60061, USA. mmiyazaki@tmriusa.com.
authors.forename: Mitsue
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Cheng
authors.initials: C
authors.lastname: Ouyang
authors.forename: Masao
authors.initials: M
authors.lastname: Yui
authors.forename: Masao
authors.initials: M
authors.lastname: Nakahashi
authors.forename: Seiko
authors.initials: S
authors.lastname: Shimizu
authors.forename: Ikuo
authors.initials: I
authors.lastname: Aoki
authors.forename: Yukuo
authors.initials: Y
authors.lastname: Morohoshi
authors.forename: James Gordon
authors.initials: JG
authors.lastname: McComb