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Proximal pulmonary artery blood flow characteristics in healthy subjects measured in an upright posture using MRI: The effects of exercise and age
Author(s) -
Cheng Christopher P.,
Herfkens Robert J.,
Taylor Charles A.,
Feinstein Jeffrey A.
Publication year - 2005
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.20333
Subject(s) - medicine , blood flow , cardiology , magnetic resonance imaging , pulmonary artery , hemodynamics , vascular resistance , nuclear medicine , radiology
Purpose To use MRI to quantify blood flow conditions in the proximal pulmonary arteries of healthy children and adults at rest and during exercise in an upright posture. Materials and Methods Cine phase‐contrast MRI was used to calculate mean flow and reverse flow index (RFI) in the main (MPA), right (RPA), and left (LPA) pulmonary arteries in healthy children and adults in an open‐MRI magnet equipped with an upright MRI‐compatible ergometer. Results From rest to exercise (150% resting heart rate), blood flow (liters/minute/m 2 ) increased in the RPA (1.4 ± 0.3 vs. 2.5 ± 0.4; P < 0.001), LPA (1.1 ± 0.3 vs. 2.2 ± 0.6; P < 0.001), and MPA (2.7 ± 0.5 vs. 4.9 ± 0.5; P < 0.001). RFI decreased in the LPA (0.040 ± 0.030 vs. 0.017 ± 0.018; P < 0.02) and MPA (0.025 ± 0.024 vs. 0.008 ± 0.007; P < 0.03). Adults experienced greater retrograde flow in the MPA than the children (0.042 ± 0.029 vs. 0.014 ± 0.012; P < 0.02). Conclusion It appears that at both rest and during exercise, in children and adults alike, RPA/LPA mean blood flow distribution is predominantly determined by distal vascular resistance, while retrograde flow is affected by proximal pulmonary bifurcation geometry. J. Magn. Reson. Imaging 2005;21:752–758. © 2005 Wiley‐Liss, Inc.