Abstract: A description is given of a method of spectral analysis of a radio frequency ultrasonic signal reflected by a structure subjected to echographic examination, comprising the steps of: a) transmitting an ultrasonic excitation signal into a portion of said structure under examination; b) receiving a radio frequency response signal from said structure; c) applying a time-frequency transform to said radio frequency response signal, dividing the radio frequency response signal into a plurality of frequency bands; d) calculating a local spectral parameter from the values of the time-frequency transform.

Abstract: The method decomposes the radio frequency signal into sub-bands by filtering, for example with a time-frequency transform. From the coefficients acquired through decomposition a matrix of spectral coefficients is obtained, from which local estimators are obtained, constituted in particular by the coefficients of the interpolating polynomials. The statistical distribution of the local estimators is evaluated in windows overlaid on the ultrasound frame. The conformation of the distribution histograms of the spectral coefficients provides a parameter which, combined with the local estimators, provides weighted local estimators, which contain spectral information useful in the identification of specific structures in the organ subjected to ultrasound analysis.

Abstract: The method comprises the phases of: sending a series of excitation ultrasonic signals to a volume being investigated, by means of an array of transducers aligned in a transverse direction (x), said ultrasonic signals propagating in depth in said volume according to a direction of propagation (y); acquiring, by means of said transducers, signals reflected from reflectors located in the volume being investigated; performing on said reflected signals a transform in the transverse direction from a spatial domain (x,y), defined by said transverse direction (x) and by said direction of propagation (y), to a first transformed domain; applying, in the transformed domain, a two-dimensional transformation, to straighten every curved image (Ip1, Ip2, Ip3) of a reflector in said volume being investigated and make it essentially orthogonal to the direction of propagation (y); compressing, in the transverse direction (x) each of the straightened curves (Im1, Im2, Im3) to concentrate said straightened image in a zone center