الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 81 |  |  |
| | | from | 81 | | |
Abstract
Computed tomography is a diagnostic tomographic imaging. It provides cross-sectional images which represent the x-ray attenuation coeffecients of the tissues present in the imaged plane. The use of computed tomography orginally was confined to the investigation of the brain. Equipment for brain scanning is now widely used and has resulted in percise diagnostic information. Position and direction of the scan plane is an aspect of the relation between computed tomographic scanning and anatomy of the brain. Though in majority of cases transverse axial and vertical coronal cross sections will deal with the anatomy of the brain. The human brain consists of well known anatomical components, some parts of these components have been shown to be concerned with certain functions. A complete cranial C.T. .examination consists of several slices obtained in sequence. These slices are about 12-17 slices depending on the thickness of the - slice. Naturally, different parts of the brain appear at different levels of the series, the ventricular system is an excellent guide. The complete set of C.T. slices of the cranium from foramen magnum to the vertex can be devided into four subsets, theses subsets may reffered to as the infraventricular, low ventricular, high ventricular and supra-ventricular. In transvesse axial tomograms, slices are oriented in relation to orbitomeatal line and the head is scanned in angle approximatly 20-25 degree in relation to this base line. In this fashio.n, the slices contain more of the ... brain and less of facial bones. The preferred slice thickness for routine examination is about 1.3 cm. The use of 8 mm. slices is recommended for supra-sellar region and posterior cranial fossa. In coronal tomograms, the cutting line is usually made about 130 degree to infraiorbitomeatal basal line. The patient lies in supine position and the head is extended suficiently. The slices obtained is about 8 mm. thickness. When C.T. is employed for detection of clinical suspected brain lesions, it is important to give contrast enhancement with intravenous injection of iodide contrast media before the examination. The study for normal C.T. anatomy of the brain at different levels in axial and coronal cut sections is useful for diagnosis and localization of focal lesions in the brain and detection of its definite anatomical site. Magnetic resonance imaging rapidly became the most recently method of medical imaging. Magnetic. R.I. allows the formation of wide variety of transverse , sagittal and coronal images of anatomy of the brain.