Spyretta Golemati, Abstract Co-Author: Nothing to Disclose

Iason Apostolakis, Abstract Co-Author: Nothing to Disclose

Aimilia Gastounioti, Abstract Co-Author: Nothing to Disclose

Nikolaos Tsiaparas, Abstract Co-Author: Nothing to Disclose

Konstantina Nikita PhD, Presenter: Nothing to Disclose

Conclusion. The suggested approach is promising for quantifying the mechanical/elastic behavior of the healthy and, more importantly, of the diseased carotid artery wall.

Mechanical displacements of the normal and diseased carotid artery wall during the cardiac cycle are important in the diagnosis of arterial disease. A number of methods have been suggested for assessing displacements in the radial and, more recently, in the longitudinal directions. The estimation of these displacements is crucial for the quantification of arterial elasticity. Elastography can subsequently be used to calculate strains based on the previously estimated displacements. Purpose. In this study, a sophisticated motion analysis algorithm, namely weighted-least-squares optical flow combined with multiscale image analysis, was used in an attempt to produce valid displacement maps of selected areas of the arterial wall. Elastography was subsequently applied to estimate strain maps of the same arterial/image areas.  

Results. Reproducible elastograms were obtained as a function of time for both healthy and atherosclerotic segments of the arterial wall. In the healthy cases, the expected uniform displacements and strains were found for the radial direction, exhibiting compression and dilation for cardiac systole and diastole, respectively; somewhat less homogeneous displacements and strains were found for the longitudinal direction. In the plaque cases, increased variability was observed in both displacement and strain maps, probably reflecting the different mechanical behavior of various plaque materials.

Materials and Methods. B-mode ultrasound images of the carotid artery were used as input to the suggested methodology. Compared to radio-frequency (rf) data, which are commonly used in elastography studies, B-mode data are more easily available and contribute to reduced computational cost. Displacement and strain maps were produced in the radial as well as in the longitudinal directions over two-three cardiac cycles.

Golemati, S, Apostolakis, I, Gastounioti, A, Tsiaparas, N, Nikita, K, Using Optical Flow and Multiscale Image Analysis to Produce Displacement and Strain Maps of the Healthy and Diseased Arterial Wall.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12038268.html