Ahmad Falahatpisheh1, Carsten Rickers2, Dominik Gabbert2, Ee Ling Heng3, Aurelien Stalder4, Hans-Heiner Kramer2, Philip J Kilner3, Arash Kheradvar1. 1. University of California Irvine, Department of Biomedical Engineering, Edwards Lifesciences Center of Advanced Cardiovascular Technology, Irvine, California, USA. 2. University Hospital Schleswig-Holstein Campus Kiel, Department of Pediatric Cardiology, Kiel, Germany. 3. Royal Brompton Hospital, London, UK, NIHR Cardiovascular Biomedical Research Unit of Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London, UK. 4. Siemens Healthcare, Erlangen, Germany.
Abstract
PURPOSE: To determine whether neglecting the flow unsteadiness in simplified Bernoulli's equation significantly affects the pulmonary transvalvular pressure drop estimation. MATERIALS AND METHODS: 3.0T magnetic resonance imaging (MRI) 4D velocity mapping was performed on four healthy volunteers, seven patients with repaired tetralogy of Fallot, and thirteen patients with transposition of the great arteries repaired by arterial switch. Pulmonary transvalvular pressure drop was estimated based on two methods: General Bernoulli's Equation (GBE), ie, the most complete form; and Simplified Bernoulli's Equation (SBE), known as 4V(2) . More than 2300 individual pressure drop measurements were used to compare the simplified and the general Bernoulli's methods. A linear mixed-effects model was employed for statistical analyses, fully accounting for clustering of observations among the methods and systolic phases. RESULTS: The simplified Bernoulli's method systematically underestimated the pressure drop compared to general Bernoulli's method during the entire systolic phase (P < 0.05), including the peak systole, where on average ΔpSBE/ΔpGBE=78%. CONCLUSION: The simplified Bernoulli method underestimated the pressure drop during all systolic phases in all the studied subjects. Therefore, it is necessary to take into account the flow unsteadiness for more accurate estimation of the pressure drop. J. Magn. Reson. Imaging 2016;43:1313-1319.
PURPOSE: To determine whether neglecting the flow unsteadiness in simplified Bernoulli's equation significantly affects the pulmonary transvalvular pressure drop estimation. MATERIALS AND METHODS: 3.0T magnetic resonance imaging (MRI) 4D velocity mapping was performed on four healthy volunteers, seven patients with repaired tetralogy of Fallot, and thirteen patients with transposition of the great arteries repaired by arterial switch. Pulmonary transvalvular pressure drop was estimated based on two methods: General Bernoulli's Equation (GBE), ie, the most complete form; and Simplified Bernoulli's Equation (SBE), known as 4V(2) . More than 2300 individual pressure drop measurements were used to compare the simplified and the general Bernoulli's methods. A linear mixed-effects model was employed for statistical analyses, fully accounting for clustering of observations among the methods and systolic phases. RESULTS: The simplified Bernoulli's method systematically underestimated the pressure drop compared to general Bernoulli's method during the entire systolic phase (P < 0.05), including the peak systole, where on average ΔpSBE/ΔpGBE=78%. CONCLUSION: The simplified Bernoulli method underestimated the pressure drop during all systolic phases in all the studied subjects. Therefore, it is necessary to take into account the flow unsteadiness for more accurate estimation of the pressure drop. J. Magn. Reson. Imaging 2016;43:1313-1319.
Authors: R Thomas Collins; Megan E Laughlin; Sean M Lang; Elijah H Bolin; Joshua A Daily; Hanna A Jensen; Morten O Jensen Journal: Prog Pediatr Cardiol Date: 2019-03-05
Authors: Fabrizio Donati; Saul Myerson; Malenka M Bissell; Nicolas P Smith; Stefan Neubauer; Mark J Monaghan; David A Nordsletten; Pablo Lamata Journal: Circ Cardiovasc Imaging Date: 2017-01 Impact factor: 7.792