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Differentiation of Abnormal Blood Flow Patterns in Coronary Arteries Based on Doppler Catheter RecordingsCardiovascular Research Institute, University of California, San Francisco
Cardiovascular Research Institute, University of California, San Francisco
Cardiovascular Research Institute, University of California, San Francisco
Cardiovascular Research Institute, University of California, San Francisco
Cardiovascular Research Institute, University of California, San Francisco
Department of Mechanical Engineering, University of California, Berkely, California Abnormal arterial blood flow patterns have been implicated as etiologic factors in thrombosis and atherosclerosis. Intravascular pulsed Doppler ultrasound techniques with fast-Fourier transform analysis offer the opportunity to measure these abnormalities. The authors hypothesized that statistical analysis of radial-directed beam spectra could be used to distinguish disturbed from nondisturbed flow and that analysis of conventional axial-directed beam spectra could then be used to distinguish laminar high-shear from laminar low-shear flow. They developed a scaled-up in-vitro model of coronary flow consisting of a glycerol/H 2O test fluid flowing through an acrylic cylinder at Reynolds numbers spanning the typical physiologic range within the coronary arteries. A scaled-up Doppler catheter with the capacity for 90° reflection of the beam was placed centrally. Disturbed flow was created by introducing a flow screen, and altered shear rates were produced by changing the Reynolds number. For the radial-directed beam studies, the coefficients of variation of the Doppler spectra for the disturbed flow states were significantly greater than for the nondisturbed flow states (p < 0.01). For the axial-directed beam studies, the coefficients of variation of the Doppler spectra for the laminar high-shear flow states were significantly greater than for the laminar low-shear flow states (p < 0.01). They conclude that abnormal blood flow patterns can be differentiated by the selective use of radial-directed and axial-directed Doppler catheter recordings.
Angiology, Vol. 42, No. 9,
711-725 (1991) |
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