title: Effects of respiratory cycle and body position on quantitative pulmonary perfusion by MRI.
abstract: OBJECTIVE
  To evaluate the performance of lung perfusion imaging using two-dimensional (2D) first pass perfusion MRI and a quantitation program based on model-independent deconvolution algorithm.
  
  
  METHODS
  In eight healthy volunteers 2D first pass lung perfusion was imaged in coronal planes using a partial Fourier saturation recovery stead state free precession (SSFP) technique with a temporal resolution of 160 ms per slice acquisition. The dynamic signal in the lung was measured over time and absolute perfusion calculated based on a model-independent deconvolution program.
  
  
  RESULTS
  In the supine position mean pulmonary perfusion was 287 ± 106 mL/min/100 mL during held expiration. It was significantly reduced to 129 ± 68 mL/min/100 mL during held inspiration. Similar differences due to respiration were observed in prone position with lung perfusion much greater during expiration than during inspiration (271 ± 101 versus 99 ± 38 mL/min/100 mL (P < 0.01)). There was a linear increase in pulmonary perfusion from anterior to posterior lung fields in supine position. The perfusion gradient reversed in the prone position with the highest perfusion in anterior lung and the lowest in posterior lung fields.
  
  
  CONCLUSIONS
  Lung perfusion imaging using a 2D saturation recovery SSFP perfusion MRI coupled with a model-independent deconvolution algorithm demonstrated physiologically consistent dynamic heterogeneity of lung perfusion distribution.
authors.affiliation: Research Department, St Francis Hospital-The Heart Center, Roslyn, New York, USA; Division of Cardiology, State University of New York at Stony Brook, Stony Brook, New York 11576, USA. jane.cao@chsli.org
authors.forename: Jie J
authors.initials: JJ
authors.lastname: Cao
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: William
authors.initials: W
authors.lastname: Schapiro
authors.forename: Jeannette
authors.initials: J
authors.lastname: McLaughlin
authors.forename: Joshua
authors.initials: J
authors.lastname: Cheng
authors.forename: Michael
authors.initials: M
authors.lastname: Passick
authors.forename: Nora
authors.initials: N
authors.lastname: Ngai
authors.forename: Philip
authors.initials: P
authors.lastname: Marcus
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Reichek
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008168:Lung / Q000473:pathology* / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D010477:Perfusion; D011187:Posture; D012119:Respiration; D016683:Supine Position