The development of new methods for defining cardiac flow events have consistently yielded important new fields of investigation for clinical cardiology from the earliest development of phonocardiography to hemodynamics, from standard pulsed and continuous wave Doppler to new color flow mapping techniques and most recently, visualization of cardiac dynamics and cardiac flows by magnetic resonance imaging. When compared to hydrodynamics and in vitro methods for characterizing flow, most of the clinical flow imaging methods appear oversimplified, and semiquantitative at best. The dynamic color flow maps and flow images now being derived in many centers have not been currently interpretable quantitatively, nor is there a clear understanding of the determinants of flow mapping by color Doppler technologies or MRI methods. We propose the development of a staged series of flow phantoms, from characterizable steady-state simple orifices to pulsatile cardiac flow models with simulated multiple valve lesions. The study of these models under reproducible hydrodynamic conditions with highly accurate in vitro techniques of flow visualization-measurement and characterization will be undertaken, including methods of computerized quantitative particle tracing, laser Doppler anemometry, and multiple flow stream thermal labeling for separate tracing of individual streams. Once the characteristics of flow within these models have been documented in detail as it relates to laminar flow regions, flow convergence regions, high velocity jets swirling and turbulence, this knowledge will be used to guide the imaging of those techniques with digital acquisition, reconstruction and redisplay of the data, recomputation and new displays. These investigations will yield an enhanced relevant flow phenomena within the cardiovascular system. The understanding of these events should aid and accelerate the development of quantitative capabilities for all cardiac imaging modalities capable of flow visualization.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL043287-05
Application #
2220979
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1990-09-01
Project End
1996-08-31
Budget Start
1994-09-01
Budget End
1996-08-31
Support Year
5
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Oregon Health and Science University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
009584210
City
Portland
State
OR
Country
United States
Zip Code
97239
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Aida, S; Shiota, T; Tsujino, H et al. (1998) Quantification of aortic regurgitant volume by a newly developed automated cardiac flow measurement method: an in vitro study. J Am Soc Echocardiogr 11:874-81
Ishii, M; Jones, M; Shiota, T et al. (1998) What is the validity of continuous wave Doppler grading of aortic regurgitation severity? A chronic animal model study. J Am Soc Echocardiogr 11:332-7
Ishii, M; Jones, M; Shiota, T et al. (1998) Temporal variability of vena contracta and jet areas with color Doppler in aortic regurgitation: a chronic animal model study. J Am Soc Echocardiogr 11:1064-71
DeGroff, C G; Baptista, A M; Sahn, D J (1998) Evaluating isovelocity surface area flow convergence method with finite element modeling. J Am Soc Echocardiogr 11:809-18
Shiota, T; Jones, M; Aida, S et al. (1997) Calculation of aortic regurgitant volume by a new digital Doppler color flow mapping method: an animal study with quantified chronic aortic regurgitation. J Am Coll Cardiol 30:834-42
Shiota, T; Jones, M; Delabays, A et al. (1997) Direct measurement of three-dimensionally reconstructed flow convergence surface area and regurgitant flow in aortic regurgitation: in vitro and chronic animal model studies. Circulation 96:3687-95
Ishii, M; Jones, M; Shiota, T et al. (1997) Quantifying aortic regurgitation by using the color Doppler-imaged vena contracta: a chronic animal model study. Circulation 96:2009-15
Shiota, T; Jones, M; Yamada, I et al. (1996) Effective regurgitant orifice area by the color Doppler flow convergence method for evaluating the severity of chronic aortic regurgitation. An animal study. Circulation 93:594-602
Shiota, T; Sinclair, B; Ishii, M et al. (1996) Three-dimensional reconstruction of color Doppler flow convergence regions and regurgitant jets: an in vitro quantitative study. J Am Coll Cardiol 27:1511-8

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