Possible application of spectral analysis techniques on ultrasonic echo-traces improved for studying changes in blood vessel walls

Abstract

Parametric algorithms previously developed by authors for spectral evaluation of biological multi-echo waveforms are adapted and improved here in order to achieve a more elevated frequency resolution. These results permit to undertake viability studies around the possible application of a new auto-regressive spectral technique to estimate physical properties like wall thickness changes in blood vessels, with accuracy enough. These difficult and sophisticated measurements in vessels have an increasing interest as tools to estimate basic parameters for calculating elastic properties in the vessel walls. Laboratory thickness data obtained for a latex phantom (mimicking vessel properties) are shown, giving a promising expectative for this improved estimation technique in blood vessels characterization, a diagnostic tool nowadays of growing attention by the researches. In fact, the results suggest clear improvement in spatial resolution, over the classic cross-correlation and non-parametric techniques, to estimate delays between pulsed signals. But, still further efforts and rigorous analyses of ultrasonic echo-signals acquired from well-controlled sanguineous tissues phantoms are needed in order to optimize the potential resolution of this new thickness measurement procedure and also to evaluate its possible clinic limitations.