Document Detail


Combined MR imaging and numerical simulation of flow in realistic arterial bypass graft models.
MedLine Citation:
PMID:  12122276     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We report methods for (a) transforming a three-dimensional geometry acquired by magnetic resonance angiography (MRA) in vivo, or by imaging a model cast, into a computational surface representation, (b) use of this to construct a three dimensional numerical grid for computational fluid dynamic (CFD) studies, and (c) use of the surface representation to produce a stereo-lithographic replica of the real detailed geometry, at a scale convenient for detailed magnetic resonance imaging (MRI) flow studies. This is applied to assess the local flow field in realistic geometry arterial bypass grafts. Results from a parallel numerical simulation and MRI measurement of flow in an aorto-coronary bypass graft with various inlet flow conditions demonstrate the strong influence of the graft inlet waveform on the perianastomotic flow field. A sinusoidal and a multi harmonic coronary flow waveform both with a mean Reynolds number (Re) of 100 and a Womersley parameter of 2.7 were applied at the graft inlet. A weak axial flow separation region just distal to the toe was found in sinusoidal flow near end deceleration (Re = 25). At the same location and approximately the same point in the cycle (Re = 30) but in coronary flow, the axial flow separation was stronger and more spatially pronounced. No axial flow separation occurred in steady flow for Re = 100. Numerical predictions indicate a region in the vicinity of the suture line (where there is a local narrowing of the graft) with a wall shear magnitude in excess of five times that associated with fully developed flow at the graft inlet.
Authors:
Y Papaharilaou; D J Doorly; S J Sherwin; J Peiro; C Griffith; N Cheshire; V Zervas; J Anderson; B Sanghera; N Watkins; C G Caro
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Biorheology     Volume:  39     ISSN:  0006-355X     ISO Abbreviation:  Biorheology     Publication Date:  2002  
Date Detail:
Created Date:  2002-07-17     Completed Date:  2002-10-04     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372526     Medline TA:  Biorheology     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  525-31     Citation Subset:  IM    
Affiliation:
Biomedical Flow Group, Aeronautics Department, Imperial College of Science, Technology and Medicine, Prince Consort Road, London, UK.
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MeSH Terms
Descriptor/Qualifier:
Computer Simulation*
Coronary Artery Bypass*
Coronary Stenosis / physiopathology,  surgery
Coronary Vessels / physiopathology*
Humans
Magnetic Resonance Angiography*
Models, Cardiovascular*
Regional Blood Flow

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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