An Automated Approach for Detection of Vessel Borders and Hard Plaques in Intravascular Ultrasound Images

Segmentation is necessary to determine the boundaries of the vessel. Intravascular ultrasound imaging (IVUS) is used for the diagnosis of coronary artery diseases. In this study, a new method is proposed for segmentation of IVUS images. First preprocessing is done to convert images from Cartesian coordinates to polar coordinates, remove the catheter in images and speckle noise with Nonlinear Anisotropic Diffusion Filtering. Then, texture features of an image are extracted using Gabor filter, and the image segmentation and determining the vessels boundary will be discussed using active contour without edge for vector value model. Calcium plaques have been determined using phase clustering and the exact boundary of calcium plaques is extracted using active contour model. This method has been tested on thirty images, and the results of the image segmentation have been validated by an expert. The area diffusion between the internal border and the expert’s opinion is 0.4310.236, and the area diffusion between the external border and the expert’s opinion is 0.6530.723. Area diffusion of calcium plaque extracted by the proposed algorithm compared with virtual histology images has been achieved equal to 5.90 percent.