A STUDY ON THE ROLE OF GRAYSCALE AND COLOUR DOPPLER ULTRASONOGRAPHY OF EXTRACRANIAL CAROTID ARTERIES IN PATIENTS OF ISCHAEMIC STROKE

Stroke is the third most common cause of death worldwide. There is a close relationship between ischemic cerebral vascular accidents and carotid artery stenosis due to various causes. Imaging of the extra cranial portion of the carotid arteries plays a important role in diagnosing various carotid artery diseases including atherosclerosis, which in turn can predict atherosclerosis of the entire vascular system of the body. Atherosclerosis of intracranial arteries is a well-recognized cause of ischemic stroke in Asians, and extracranial carotid artery disease is more often seen in western countries. Due to its wide availability, USG can be used as an important diagnostic tool for proper evaluation of patients of cerebrovascular accident in emergency setting. This paper aims to discuss the results of our hospital based cross sectional study on the various morphological and physiological changes taking place in the extracranial portion of carotid arteries as an underlying pathological process in patients presenting with signs and symptoms of cerebrovascular insufficiency. Increased IMT, presence of plaque, and evaluation of plaque characteristics such as types, surface, sites, morphology, etc. can be useful to estimate the predictable risk for a cerebrovascular event in the future. Echolucency of plaque, intraplaque hemorrhage, and plaque ulceration are plaque morphologies, that have been found to be associated with increased risk of Ischaemic stroke. In addition to that, doppler velocity parameters of the stenotic segments can provide information about the resultant changes in the hemodynamics.