title: A new high-resolution spectral approach to noninvasively evaluate wall deformations in arteries.
abstract: By locally measuring changes on arterial wall thickness as a function of pressure, the related Young modulus can be evaluated. This physical magnitude has shown to be an important predictive factor for cardiovascular diseases. For evaluating those changes, imaging segmentation or time correlations of ultrasonic echoes, coming from wall interfaces, are usually employed. In this paper, an alternative low-cost technique is proposed to locally evaluate variations on arterial walls, which are dynamically measured with an improved high-resolution calculation of power spectral densities in echo-traces of the wall interfaces, by using a parametric autoregressive processing. Certain wall deformations are finely detected by evaluating the echoes overtones peaks with power spectral estimations that implement Burg and Yule Walker algorithms. Results of this spectral approach are compared with a classical cross-correlation operator, in a tube phantom and "in vitro" carotid tissue. A circulating loop, mimicking heart periods and blood pressure changes, is employed to dynamically inspect each sample with a broadband ultrasonic probe, acquiring multiple A-Scans which are windowed to isolate echo-traces packets coming from distinct walls. Then the new technique and cross-correlation operator are applied to evaluate changing parietal deformations from the detection of displacements registered on the wall faces under periodic regime.
authors.affiliation: ESIME Zacatenco, Instituto Politécnico Nacional (IPN), Avenue IPN, s/n, 07738 Mexico, DF, Mexico.
authors.forename: Ivonne
authors.initials: I
authors.lastname: Bazan
authors.affiliation: Departamento de Materiales, Facultad de Ciencias, Universidad de la Republica, 14200 Montevideo, Uruguay.
authors.forename: Carlos
authors.initials: C
authors.lastname: Negreira
authors.affiliation: Institute of Physical & Information Technologies, CSIC, Serrano 144, 28006 Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ramos
authors.affiliation: Departamento de Materiales, Facultad de Ciencias, Universidad de la Republica, 14200 Montevideo, Uruguay.
authors.forename: Javier
authors.initials: J
authors.lastname: Brum
authors.affiliation: ESIME Zacatenco, Instituto Politécnico Nacional (IPN), Avenue IPN, s/n, 07738 Mexico, DF, Mexico.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Ramirez
mesh_terms: D000465:Algorithms; D001158:Arteries / Q000502:physiology*; D050197:Atherosclerosis / Q000473:pathology; D001794:Blood Pressure; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000473:pathology; D002339:Carotid Arteries / Q000473:pathology; D055119:Elastic Modulus; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008962:Models, Theoretical; D019047:Phantoms, Imaging