title: Assessment of left atrial volumes at 1.5 Tesla and 3 Tesla using FLASH and SSFP cine imaging.
abstract: OBJECTIVE
  To investigate left atrial volumes and function and their variability in healthy volunteers using steady state free precession (SSFP) and fast low angle shot (FLASH) sequences at both 1.5 and 3 T using both the short-axis and biplane area-length methods.
  
  
  METHODS
  Ten healthy volunteers underwent CMR at both 1.5 and 3 Tesla. The biplane area-length method utilized volumes from the horizontal and vertical long axis images.
  
  
  RESULTS
  There were no significant differences between left atrial short-axis volumes or function between 1.5 and 3 T assessed using either FLASH or SSFP sequences. The biplane area-length method underestimated maximal left atrial volume using FLASH by 12 mL at 3 T (18%) and by 10 mL (14%) at 1.5 T (p = 0.003 and p = 0.05 respectively). Variability was larger for left atrial measurements using the biplane area-length method.
  
  
  CONCLUSIONS
  Field strength had no effect on left atrial volume and function assessment using either FLASH or SSFP. The use of the short-axis method for the acquisition of left atrial parameters is more reproducible than the biplane area-length for serial measurements.
authors.affiliation: University of Oxford Centre for Clinical Magnetic Resonance Research, Department of Cardiovascular Medicine, University of Oxford, The John Radcliffe Hospital, Oxford, United Kingdom. lucy.hudsmith@cardiov.ox.ac.uk
authors.forename: L E
authors.initials: LE
authors.lastname: Hudsmith
authors.forename: A S H
authors.initials: AS
authors.lastname: Cheng
authors.forename: D J
authors.initials: DJ
authors.lastname: Tyler
authors.forename: C
authors.initials: C
authors.lastname: Shirodaria
authors.forename: J
authors.initials: J
authors.lastname: Lee
authors.forename: S E
authors.initials: SE
authors.lastname: Petersen
authors.forename: J M
authors.initials: JM
authors.lastname: Francis
authors.forename: Kieran
authors.initials: K
authors.lastname: Clarke
authors.forename: M D
authors.initials: MD
authors.lastname: Robson
authors.forename: S
authors.initials: S
authors.lastname: Neubauer
mesh_terms: D000328:Adult; D002306:Cardiac Volume; D005260:Female; D006325:Heart Atria / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D009929:Organ Size; D015203:Reproducibility of Results