Ultrasound Image Analysis of Carotid Artery

Arteries are pathways for blood to travel over our body. Carotid Artery is present in the neck of our human body. Carotid artery carries blood from the heart to our brain. There are two Carotid Arteries in our neck, they are Right Carotid Artery (RCA) and Left Carotid Artery (LCA). The Carotid Arteries are divided into two branches, Internal Carotid Artery (ICA) and External Carotid artery (ECA) respectively. The Internal Carotid Artery (ICA) takes the blood to the brain whereas the External Carotid Artery (ECA) takes the blood to the face and neck. Common Carotid Artery (CCA) is made of three layers. Intima is the first layer which is the underlying smooth layer. Media is the second layer which is present in the middle and looks muscular. Adventitia is the third outer layer. In India the occurrence of Stroke has been drastically increased. Stroke occurs when an unanticipated blood clot in the Carotid Artery interrupts the blood flow to the brain or when a plaque in the Carotid Artery moves towards our brain. Carotid Artery Atherosclerosis (CAA) also known as Carotid Artery Disease (CAD) is caused by the plaque in the Carotid Artery. Plaques are nothing but tussocks of Cholesterol, Calcium, stringy tissues and other cellular lees. When plaque starts growing it starts to narrow the Carotid Artery known as Carotid Artery Stenosis (CAS). Carotid Artery Stenosis also leads to Stroke. There are various tests available to test the Carotid Artery like Ultrasound Imaging, Angiogram, Computed Tomography Angiography (CTA Scan), Magnetic Resonance Angiography (MRA) and Carotid Sinus Massage (CSM). They use Ultrasound imaging for analysing the Carotid Artery as it is cheaper and less time consuming. Ultrasound Image of Carotid Artery is taken by placing a probe against our neck region and sound waves get reflected and then the computer constructs an image based on the sound waves from the Ultrasound probe. Ultrasound images can show the blood flow in the artery, the plaques in the artery and narrowing of the artery, etc. We use Ultrasound Images in our project to analyse the Carotid Artery by using various Image Processing Algorithms. Our project is to pre-process the Ultrasound Image and perform Segmentation of the images by using Image Processing Algorithms. We have used Otsu's Thresholding, Density Based Spatial Clustering Applications with Noise (DBSCAN), Watershed Algorithm and Gaussian Mixture Model (GMM) based Segmentation to segment the Ultrasound Images of Carotid Artery. After the Segmentation step only we can compute the Intima Media Thickness (IMT).