title: Pulmonary regurgitant volume is superior to fraction using background-corrected phase contrast MRI in determining the severity of regurgitation in repaired tetralogy of Fallot.
abstract: In the assessment of pulmonary regurgitation (PR) using phase contrast MRI, phase offset errors affect the accuracy of flow. This study evaluated the use of automated background correction for phase offset in the quantification of PR fraction and volume in patients with repaired tetralogy of Fallot (TOF), and to assess its clinical impact. We retrospectively analyzed 203 cardiac MRI studies, performed on 1.5-T scanner. Pulmonary flow (Q(P)) and systemic flow (Q(S)) was assessed both with and without background correction. Non-corrected and corrected Q(P) was correlated with Q(S). PR was correlated with (1) indexed right ventricular end-diastolic volume (RVEDVi) and (2) with differential right and left ventricular stroke volumes (PR(SV)). Both PR fraction and volume showed major change after correction (-43 to +36% and -13 to +13 ml/m(2)). Corrected Q(P) and Q(S) were stronger correlated with each other than non-corrected Q(P) and Q(S) [r = 0.78 vs. 0.73 (p < 0.001)]. Both PR fraction and volume were stronger correlated with RVEDVi, compared to their non-corrected counterparts (p < 0.001). PR volume was stronger correlated with RVEDVi, compared to PR fraction [r = 0.74 vs. 0.69 (p < 0.001)]. When patients were divided according to PR severity, 12% of patients reclassified after correction. Background correction for phase offset significantly changed the quantification of PR. Non-corrected assessment of PR may result in the misclassification of patients. Our data suggest that the use of PR volume is favourable in the follow-up of patients with repaired TOF.
authors.affiliation: Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands, tm.gorter@umcg.nl.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Gorter
authors.forename: Joost P
authors.initials: JP
authors.lastname: van Melle
authors.forename: Hendrik G
authors.initials: HG
authors.lastname: Freling
authors.forename: Tjark
authors.initials: T
authors.lastname: Ebels
authors.forename: Beatrijs
authors.initials: B
authors.lastname: Bartelds
authors.forename: Petronella G
authors.initials: PG
authors.lastname: Pieper
authors.forename: Rolf M F
authors.initials: RM
authors.lastname: Berger
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: van Veldhuisen
authors.forename: Tineke P
authors.initials: TP
authors.lastname: Willems
mesh_terms: D000328:Adult; D001331:Automation; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D015588:Observer Variation; D011237:Predictive Value of Tests; D011652:Pulmonary Circulation; D011665:Pulmonary Valve Insufficiency / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013771:Tetralogy of Fallot / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult