Application of Cardinal Points Symmetry Landmarks Distribution Model to B-Mode Ultrasound Images of Transverse Cross-section of Thin-walled Phantom Carotid Arteries

We had earlier developed a technique based on cardinal point symmetry landmark distribution model (CPS-LDM) to completely characterize the Region of Interest (ROI) of the geometric shape of thick-walled simulated B-mode ultrasound images of carotid artery imaged in the transverse plane. In this paper, this developed technique was applied to completely characterize the region of interest of the geometric shape of B-mode ultrasound images of thin-walled phantom carotid artery imaged in the transverse plane. The developed model employs a combination of fixed landmarks (FLs) and movable landmarks (MLs) to obtain the total landmarks (TLs) that can sufficiently segment the shape of the ROI of the carotid artery. For the phantom carotid arteries, three FLs are fixed on each of the four ROIs determined by the cardinal points North (N), South (S), East (E) and West (W) drawn on the ROIs of the phantom carotid artery. The MLs are determined by the inter-cardinal directions such as North-East (NE), North-West (NW) and so on. The obtained CPS-LDM equation developed allows graphical visualization the optimum number of points that can sufficiently segment the ROIs. ImageJ2 software was used to generate the Cartesian coordinates for each landmark which were then used to generate the Shape Space Pattern (SSP) of the phantom carotid artery ready for further statistical analysis. The results showed that the CPS-LD model is generic and adaptable to a variety of transverse cross-sectional B-mode ultrasound images of thin-walled phantom carotid artery