الفهرس 
Anatomy of the Arterial System of Head and NeckOnly 14 pages are availabe for public view
 |  | from | 175 |  |  |
| | | from | 175 | | |
Abstract
The present study provides a detailed correlation between the anatomy of carotid and vertebrobasilar arterial systems and their visualization by different imaging modalities, both in health and disease. The fast pacing advances in imaging technologies made the visualization of the arterial systems of the head and neck much easier helping the clinicians to understand the nature of these areas and to clearly diagnose extra- and intra-cranial vascular diseases and tailor the ways of intervention.
The imaging of arterial systems began first with the ultrasound that allowed for the visualization of vessels in a gray scale image. Then it was developed to provide a color image and even a 3D image. Currently, Duplex scan (the most advanced form of ultrasound), allowed for the visualization and hearing of the blood flow within the artery helping in the diagnosis of serious diseases that affect the arteries in the head and neck region. Although ultrasound was the primary and the safest of all modalities, yet it couldn’t answer serious questions concerning the grade of stenoses, the exact composition of plaque and the precise diagnosis of certain diseases especially those present in the intracranial territory.
Thence, the invasive technique named “catheter- based angiography” was developed, which until today is considered the “gold standard” technique in the imaging of the arterial system. Its ability to visualize the exact area of interest in clearly detailed images made it the modality of choice in the diagnosis and the decision making in major intra- and extracranial arterial diseases affecting the carotid and vertebrobasilar systems. The mechanism of catheter based angiography depends on the introduction of the catheter through the femoral artery or vein and following its path by the use of X-ray till reaching the carotid system . The together with injection of a contrast material allow the thorough visualization of the arteries both intra and extracranially. The catheter -based angiography gives detailed data about the state of the arterial wall, and the condition of the artery along its course and its branches. The use of the catheter based angiography answered many questions in terms of diagnosis and even in treatment of arterial abnormalities as it paved the way for the use of stents and balloon dilators in cases of stenoses. Its invasiveness and high cost due to hospital admission and its inability to diagnose certain cases as those of arterial aneurysms; made the search for a non invasive technique that can give an image equivalent to that of catheter angiography mandatory since the medical field is rapidly shifting from invasive modalities to non invasive ones.
The present study demonstrates the ability of Computed Tomography Angiography to examine the vessel in various planes then integrating all these planes into an image showing the course of any artery, its various kinks and its numerous branches. With the advancing of the technique the images were developed from greyscale to colored images and from colored images to 3D images, giving a clear view of the examined artery. Although Computed Tomography Angiography was able to answer many questions regarding the artery and its relations to bony structures. However, it failed to outline the relations of the artery to soft tissue and this made it of particular significance to develop a new modality capable of visualizing both bone and soft tissues essentially for the accurate diagnosis and management.
Finally, the emergence of Magnetic Resonance Angiography was a major breakthrough in the field non invasive imaging. The advancement in the technique with the use of stronger magnets, made the demonstration of the artery for clinical purposes easier and in a non invasive manner. The advancing technology used made it possible to demonstrate the areas of interest and to establish its relations not only to bones but also to soft tissue making it possible to understand the course, relations and branches of the artery and clearly visualizing any abnormality regardless to its presence near a bony cavity or near an organ or even the vasculature inside a mass. The produced highly defined image made it possible to clearly pinpoint the diseased area, removing or adding structures that can help in identifying the relation between the diseased area and its surrounding structures , thus facilitating the process of diagnosis and consequent treatments