Document Detail


Doppler color flow mapping of the proximal isovelocity surface area: a new method for measuring volume flow rate across a narrowed orifice.
MedLine Citation:
PMID:  1910832     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This manuscript describes a new method, validated in in vitro models, for quantitating volume flow rate across an orifice with Doppler color flow mapping. Flow through a narrowed orifice is characterized by the convergence of radial streamlines proximal to the orifice. In this color Doppler method, one or more isovelocity surface areas (PISA), delineated by blue and red aliasing velocity interfaces, can be identified proximal to the narrowed orifice. Volume flow rate (in milliliters per second) can then be calculated as PISA (in square centimeters) multiplied by the isovelocity of the PISA (in centimeters per second). Doppler color flow mapping was performed in in vitro models of constant and pulsatile flow through an orifice in a wall. The first proximal isovelocity surface area, with an isovelocity corresponding to the aliasing velocity, that is, one half the Nyquist sampling limit, could be identified as a blue and red color interface proximal to the orifice. Over a range of circular orifice diameters from 3 mm to 16 mm and flow rates from 0.5 to 18.7 L/min, the proximal isovelocity surface area could be imaged in two planes. This PISA was best described by a hemielliptic mathematical model with two different radii measured from long-axis and short-axis views. In the constant flow model, volume flow rate calculated from the Doppler PISA correlated well with actual volume flow rate measured simultaneously with a cylinder and stopwatch (r = 0.98, p less than 0.001, standard error of the estimate [SEE] = 0.36 L/min). In the pulsatile flow model, with jet velocities ranging from 2.6 to 7.7 m/sec and flow volume ranging from 1.0 to 10.3 L/min, calculated volume flow rate also demonstrated an excellent correlation with actual volume flow rate (r = 0.99, p less than 0.001, SEE = 0.53 L/min). Findings from these in vitro models suggest that quantification of the proximal isovelocity surface area by Doppler color flow mapping appears to be a promising technique for estimating volume flow rate across a narrowed orifice. This new color Doppler flow method may have advantages over previous Doppler methods in estimating volume flow rate in various clinical situations, for example, valvular regurgitation and shunt lesions.
Authors:
T Utsunomiya; T Ogawa; H A Tang; R Doshi; D Patel; M Quan; W L Henry; J M Gardin
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography     Volume:  4     ISSN:  0894-7317     ISO Abbreviation:  J Am Soc Echocardiogr     Publication Date:    1991 Jul-Aug
Date Detail:
Created Date:  1991-11-05     Completed Date:  1991-11-05     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8801388     Medline TA:  J Am Soc Echocardiogr     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  338-48     Citation Subset:  IM    
Affiliation:
Department of Medicine, University of California, Irvine.
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MeSH Terms
Descriptor/Qualifier:
Blood Flow Velocity
Echocardiography, Doppler / methods*
Humans
Mathematics
Models, Cardiovascular*
Models, Structural
Models, Theoretical
Pulsatile Flow
Reproducibility of Results

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


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