• Sahn, David (PI)

Project: Research project

Project Details


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.
Effective start/end date9/1/908/31/96


  • National Institutes of Health


  • Medicine(all)


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