title: [Reference values of MRI flow measurements of the pulmonary outflow tract in healthy children].
abstract: OBJECTIVE
  To provide reference values for MRI-based flow measurements in the main pulmonary artery in healthy children.
  
  
  METHODS
  In 98 healthy children (age: 3 - 17 years, median: 11 years), the main pulmonary artery was examined using MRI-based flow measurements with high temporal resolution (9.6 ms per cardiac phase).
  
  
  RESULTS
  The acceleration time revealed a distinct age dependency and varied between 90 and 155 ms (mean: 124 ms +/- 14). The relative acceleration time (related to the RR-interval) varied between 12.7 and 27 % (mean: 18 % +/- 2.6). The mean values and the standard deviations for the determined values were as follows: cardiac output (5.4 l/min +/- 1.4), cardiac output normalized to the body surface area (4.2 [l/min]/m(2) +/- 0.8), average systolic flow velocity (66 cm/s +/- 12), maximum systolic flow (309 ml/s +/- 79), mean flow (110 ml/s +/- 30), distensibility of the wall of the main pulmonary artery (79 % +/- 26), peak velocity (96 cm/s +/- 15), pressure gradient along the pulmonary valve (3.8 mm Hg +/- 1.2), stroke volume (63.2 ml +/- 17.9), acceleration volume (23.7 ml +/- 8.7), maximum acceleration of flow (4924 ml/s(2) +/- 1431), and reverse volume (0.2 ml +/- 0.3).
  
  
  CONCLUSIONS
  The acquired values of reference are applicable to all pediatric patients and serve as a framework for the communication between the radiologist and the pediatric cardiologists. High temporal resolution of the measurement sequence is mandatory. Noticeable deviations of these values should induce additional (probably invasive) evaluation.
authors.affiliation: Institut für Diagnostische und Interventionelle Radiologie, Johann Wolfgang Goethe-Universität, Frankfurt am Main. Abolmaali@em.uni-frankfurt.de
authors.forename: N D
authors.initials: ND
authors.lastname: Abolmaali
authors.forename: A
authors.initials: A
authors.lastname: Esmaeili
authors.forename: P
authors.initials: P
authors.lastname: Feist
authors.forename: H
authors.initials: H
authors.lastname: Ackermann
authors.forename: M
authors.initials: M
authors.lastname: Requardt
authors.forename: H
authors.initials: H
authors.lastname: Schmidt
authors.forename: T J
authors.initials: TJ
authors.lastname: Vogl
mesh_terms: D000293:Adolescent; D001783:Blood Flow Velocity; D002648:Child; D002675:Child, Preschool; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011651:Pulmonary Artery / Q000502:physiology*; D012016:Reference Values; D012044:Regression Analysis; D012129:Respiratory Function Tests; D013318:Stroke Volume; D013599:Systole