title: Comparative Evaluation of Flow Quantification across the Atrioventricular Valve in Patients with Functional Univentricular Heart after Fontan's Surgery and Healthy Controls: Measurement by 4D Flow Magnetic Resonance Imaging and Streamline Visualization.
abstract: OBJECTIVE
  To evaluate the inflow pattern and flow quantification in patients with functional univentricular heart after Fontan's operation using 4D flow magnetic resonance imaging (MRI) with streamline visualization when compared with the conventional 2D flow approach.
  
  
  METHODS
  Seven patients with functional univentricular heart after Fontan's operation and twenty-three healthy controls underwent 4D flow MRI. In two orthogonal two-chamber planes, streamline visualization was applied, and inflow angles with peak inflow velocity (PIV) were measured. Transatrioventricular flow quantification was assessed using conventional 2D multiplanar reformation (MPR) and 4D MPR tracking the annulus and perpendicular to the streamline inflow at PIV, and they were validated with net forward aortic flow.
  
  
  RESULTS
  Inflow angles at PIV in the patient group demonstrated wide variation of angles and directions when compared with the control group (P < .01). The use of 4D flow MRI with streamlines visualization in quantification of the transatrioventricular flow had smaller limits of agreement (2.2 ± 4.1 mL; 95% limit of agreement -5.9-10.3 mL) when compared with the static plane assessment from 2DFlow MRI (-2.2 ± 18.5 mL; 95% limit of agreement agreement -38.5-34.1 mL). Stronger correlation was present in the 4D flow between the aortic and trans-atrioventricular flow (R2correlation in 4D flow: 0.893; in 2D flow: 0.786).
  
  
  CONCLUSIONS
  Streamline visualization in 4D flow MRI confirmed variable atrioventricular inflow directions in patients with functional univentricular heart with previous Fontan's procedure. 4D flow aided generation of measurement planes according to the blood flood dynamics and has proven to be more accurate than the fixed plane 2D flow measurements when calculating flow quantifications.
authors.affiliation: Department of Radiology, Princess Margaret Hospital, Hong Kong, SAR.
authors.forename: Hoi Lam
authors.initials: HL
authors.lastname: She
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Arno A W
authors.initials: AA
authors.lastname: Roest
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Emmeline E
authors.initials: EE
authors.lastname: Calkoen
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: van den Boogaard
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Rob J
authors.initials: RJ
authors.lastname: van der Geest
authors.affiliation: Department of Thoracic Surgery, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Mark G
authors.initials: MG
authors.lastname: Hazekamp
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: de Roos
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Jos J M
authors.initials: JJ
authors.lastname: Westenberg
mesh_terms: D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity; D002648:Child; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006351:Heart Valves / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006352:Heart Ventricles / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006439:Hemodynamics; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D010865:Pilot Projects; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
keywords: 4D Flow; Fontan; Magnetic Resonance Imaging