Premium
In vitro assessment of flow patterns and turbulence intensity in prosthetic heart valves using generalized phase‐contrast MRI
Author(s) -
Kvitting JohnPeder Escobar,
Dyverfeldt Petter,
Sigfridsson Andreas,
Franzén Stefan,
Wigström Lars,
Bolger Ann F.,
Ebbers Tino
Publication year - 2010
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.22163
Subject(s) - turbulence kinetic energy , turbulence , biomedical engineering , intensity (physics) , materials science , heart valve , phase contrast microscopy , medicine , cardiology , physics , mechanics , optics
Purpose: To assess in vitro the three‐dimensional mean velocity field and the extent and degree of turbulence intensity (TI) in different prosthetic heart valves using a generalization of phase‐contrast MRI (PC‐MRI). Materials and Methods: Four 27‐mm aortic valves (Björk‐Shiley Monostrut tilting‐disc, St. Jude Medical Standard bileaflet, Medtronic Mosaic stented and Freestyle stentless porcine valve) were tested under steady inflow conditions in a Plexiglas phantom. Three‐dimensional PC‐MRI data were acquired to measure the mean velocity field and the turbulent kinetic energy (TKE), a direction‐independent measure of TI. Results: Velocity and TI estimates could be obtained up‐ and downstream of the valves, except where metallic structure in the valves caused signal void. Distinct differences in the location, extent, and peak values of velocity and TI were observed between the valves tested. The maximum values of TKE varied between the different valves: tilting disc, 100 J/m 3 ; bileaflet, 115 J/m 3 ; stented, 200 J/m 3 ; stentless, 145 J/m 3 . Conclusion: The TI downstream from a prosthetic heart valve is dependent on the specific valve design. Generalized PC‐MRI can be used to quantify velocity and TI downstream from prosthetic heart valves, which may allow assessment of these aspects of prosthetic valvular function in postoperative patients. J. Magn. Reson. Imaging 2010;31:1075–1080. © 2010 Wiley‐Liss, Inc.