Non Invasive Evaluation Of Extracranial Arteries

Non-invasive studies of the extracranial arteries consist of the direct and indirect use of ultrasound methods. The direct tests examine the anatomy and the physiology of the carotid artery while the indirect tests evaluate the hemodynamic changes of its distal branches (the orbital and brain circulation). Ultrasonography by Doppler evaluates the hemodynamic parameters particularly the speed of blood flow and the characteristics of the flow. This modality evaluates the supraorbital arteries, common carotid, external carotid, internal carotid and vertebral arteries of the neck. There are two types of peripheral arterial studies: · Physiological studies – these studies are of functional measures that include analysis of Doppler wave with response to the compression, measures of transcutaneous oxygen pressure or plethysmography. · A duplex scanning is an ultrasonic study where images and structures are shown in two dimensions and in real time. It also includes a spectral analysis with speed of blood flow. <a id="