Carotid plaque tissue differentiation based on radiofrequency echographic signal local spectral content (RULES: Radiofrequency Ultrasonic Local Estimators)

An echographic method is proposed in order to detect and differentiate carotid vessel plaques. The method based on a novel spectral processing procedure for the radiofrequency echo signal is named RULES (radiofrequency ultrasonic local estimators). It allows the extraction of local spectral parameters related to the organization and mechanical properties of an investigated tissue region. Spectral images are produced through a processing procedure, based on a statistical analysis of radiofrequency signal spectral coefficients, calculated with the discrete wavelet packet transform. For each organ, the regions of the investigated tissue, which exhibit the same distribution of the spectral coefficients, were considered homogeneous and were put in correspondence with local tissue condition (healthy or with pathology), as derived from histological analysis.