IVUS transverse blood flow: dynamic noise suppression

In recent years, a new method to measure transverse blood flow, based on the decorrelation of the radio frequency (RF) signals has been developed. We investigated a new method on noise estimation based on correlation. The decorrelation characteristics of transverse blood flow using an intravascular ultrasound (IVUS) array catheter are studied by means of computer modeling. Blood was simulated as a collection of randomly located point scatterers; moving this scattering medium transversally across the acoustical beam represented flow. Parabolic blood flow was simulated. Assuming additive noise, noise at a given signal-to-noise ratio is added to the RF signals. Next, a new correlation-based method to dynamically estimate and suppress the noise present in the RF signals from blood is implemented. The decorrelation due to noise is estimated from the correlation coefficients from flowing blood obtained at increasing time lags. The relation between these correlation coefficients will be dominated by the flow, and the decorrelation due to noise can be estimated. The method shows how to estimate and correct the correlation coefficients for noise