Blood velocity estimation with high frequency intravascular ultrasound

When a cluster of randomly distributed blood particles moves across the ultrasound beam, the received echo signals decorrelate as a function of time. This phenomenon may be used to estimate the flow velocity by measuring the decorrelation rate from a sequence of blood scattering signals. A computer model based on the impulse response method was used to study the lateral decorrelation properties of an IVUS transducer from the extreme near-field up to the far-field. An RF decorrelation-based method for measuring local blood velocity and quantifying volume flow from cross-sectional RF IVUS data was developed and tested in vitro with a flow phantom and in vivo in pig experiments. Preliminary results of this study indicate that the proposed decorrelation method is able to extract 2D velocity profiles and volumetric flow.