الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The presence of an intracranial aneurysm is a serious medical condition that can lead to permanent neurological deficit or death if the aneurysm ruptures. Therefore, the techniques used for detection of unruptured aneurysms should have very high sensitivity as well as specificity to be useful. High resolution CTA have become important in the diagnosis and characterization of vascular pathology. It produces high resolution image volumes that may take a relatively long time to read without proper tools .CTA provides a highly sensitive and specific method for detection and evaluation of cerebral aneurysms in all cases. A recent study by Karamessini and colleagues quotes a 93-100% sensitivity and 100% specificity for aneurysms 3mm or larger. These values are comparable with conventional angiography. Advantages of CTA over conventional angiography include decreased cost, invasiveness and time to diagnosis. Patients with subarachnoid haemorrhage is usually diagnosed on CT, the CTA acquisition can be performed without a large penalty in examination time. Conventional angiography need skill level to perform and has a risk of permanent neurologic deficit. CTA has several advantages, which include fast acquisition time, acceptance of the examination in acute setting and provides the information about the relationship between the vessels and the bony structure.