Estimation of blood velocity with high frequency ultrasound

摘要

In order to map blood velocity in small regions near thentransducer, we evaluate the performance of the wideband maximumnlikelihood (WMLE) strategy and infinite impulse response (IIR) filtersnfor blood velocity estimation with a transducer center frequency of 38nMHz. Using a short transmitted pulse and the narrow lateral beam widthnobtained using this frequency, we show that velocities smaller than 1nmm/s can be estimated reliably. In addition, using both changes in thenlocation and magnitude of the peak of the RF correlation, vessels asnsmall as 40 Μm can be visualized in the RF signal and distinguishednfrom stationary tissue. The experimental system also provides thenopportunity to examine changes in flow and in the vessel wall over ancardiac cycle