title: Right ventricular systolic function in hypoplastic left heart syndrome: A comparison of manual and automated software to measure fractional area change.
abstract: BACKGROUND
  Quantitative echocardiographic assessment of right ventricular function is important in children with hypoplastic left heart syndrome (HLHS). The aim of this study was to examine the repeatability of different echocardiographic techniques, both manual and automated, to measure fractional area change (FAC) in patients with HLHS and to correlate these measurements with magnetic resonance imaging (MRI)-derived ejection fraction (EF).
  
  
  METHODS
  Fifty-one children with HLHS underwent transthoracic echocardiography and cardiac MRI under the same general anesthetic as part of routine inter-stage assessment. FAC was measured from the apical four-chamber view using three different techniques: velocity vector imaging (VVI) (Syngo USWP 3.0; Siemens Healthineers), QLAB (Q-lab R 10.0; Philips Healthcare), and manual endocardial contour tracing (Xcelera, Philips Healthcare). Intra- and inter-observer variability was calculated using intra-class correlation coefficient (ICC). FAC was correlated with MRI EF calculated using a single standard method.
  
  
  RESULTS
  Fractional area change had a good correlation with MRI-derived EF with an R value for VVI, QLAB, and manual methods of .7, .6, and .4, respectively. Intra- and inter-observer variability for FAC was good for automated echocardiographic methods (ICC>.85) but worse for manual method particularly inter-observer variability of FAC and end-systolic area. Both automated techniques tended to produce higher FAC values compared with manual measurements (P<.001).
  
  
  CONCLUSIONS
  Automation improves the repeatability of FAC in HLHS. There are some differences between automated software in terms of correlation with MRI-derived EF. Measurement bias and wide limits of agreement mean that the same echocardiographic technique should be used during the follow-up of individual patients.
authors.affiliation: Department of Pediatric Cardiology, Children's Hospital, University Hospital of Helsinki and University of Helsinki, Helsinki, Finland.|Department of Pediatrics, Kuopio University Hospital, Kuopio, Finland.
authors.forename: Hanna K
authors.initials: HK
authors.lastname: Ruotsalainen
authors.affiliation: Department of Congenital Heart Disease, Evelina London Children's Hospital, London, United Kingdom.
authors.forename: Hannah R
authors.initials: HR
authors.lastname: Bellsham-Revell
authors.affiliation: Department of Congenital Heart Disease, Evelina London Children's Hospital, London, United Kingdom.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Bell
authors.affiliation: Department of Pediatric Cardiology, Children's Hospital, University Hospital of Helsinki and University of Helsinki, Helsinki, Finland.
authors.forename: Jaana I
authors.initials: JI
authors.lastname: Pihkala
authors.affiliation: Department of Pediatric Cardiology, Children's Hospital, University Hospital of Helsinki and University of Helsinki, Helsinki, Finland.
authors.forename: Tiina H
authors.identifier: http://orcid.org/0000-0001-9092-7763
authors.initials: TH
authors.lastname: Ojala
authors.affiliation: Department of Congenital Heart Disease, Evelina London Children's Hospital, London, United Kingdom.
authors.forename: John M
authors.initials: JM
authors.lastname: Simpson
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000150:complications* / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012984:Software; D018497:Ventricular Dysfunction, Right / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology
keywords: automation; fractional area change; hypoplastic left heart syndrome; myocardial function; velocity vector imaging