title: Horizontal Long Axis Imaging Plane for Evaluation of Right Ventricular Function on Cardiac Magnetic Resonance Imaging.
abstract: OBJECTIVE
  The purpose of this study was to evaluate a horizontal long axis (HLA) magnetic resonance imaging (MRI) plane aligned to the long axis of the right ventricular (RV) cavity for functional analysis by comparing the measurement variability and time required for the analysis with that using a short-axis (SAX) image orientation.
  
  
  METHODS
  Thirty-four cardiac MRI exams with cine balanced steady-state free precession image stacks in both the SAX and the HLA of the RV (RHLA) were evaluated. Two reviewers independently traced RV endocardial borders on each image of the cine stacks. The time required to complete each set of traces was recorded, and the RV end-diastolic volume, end-systolic volume, and ejection fraction were calculated. Analysis times and RV measurements were compared between the two orientations.
  
  
  RESULTS
  Analysis time for each reviewer was significantly shorter for the RHLA stack (reviewer 1 = 6.4 ± 1.8 min, reviewer 2 = 6.0 ± 3.3 min) than for the SAX stack (7.5 ± 2.1 and 6.9 ± 3.6 min, respectively;P< 0.002). Bland-Altman analysis revealed lower mean differences, limits of agreement, and coefficients of variation for RV measurements obtained with the RHLA stack.
  
  
  CONCLUSIONS
  RV functional analysis using a RHLA stack resulted in shorter analysis times and lower measurement variability than for a SAX stack orientation.
authors.affiliation: Department of Radiology, University of Washington School of Medicine, 1959 Pacific Street, Seattle, WA, USA; Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, NY, USA.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Chaturvedi
authors.affiliation: Department of Radiology, University of Washington School of Medicine, 1959 Pacific Street, Seattle, WA, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Whitnah
authors.affiliation: Department of Radiology, University of Washington School of Medicine, 1959 Pacific Street, Seattle, WA, USA.
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Maki
authors.affiliation: Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, NY, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Baran
authors.affiliation: Department of Radiology, University of Washington School of Medicine, 1959 Pacific Street, Seattle, WA, USA; Department of Radiology, Straub Clinic and Hospital, Honolulu, HI, NY, USA.
authors.forename: Lee M
authors.initials: LM
authors.lastname: Mitsumori
keywords: Analysis time; magnetic resonance imaging; observer variability; right ventricle; ventricular function