IntroductionStroke is a term that describes the sudden onset of a constant neurological deficit caused by partial or complete obstruction (ischemic stroke) or rupture of a vessel cerebral blood (hemorrhage). (1) Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Stroke is the second most common cause of morbidity worldwide and is the leading cause of acquired disability, ischemic stroke, which constitutes the vast majority of cases (~85%), risk factors for ischemic stroke include age, sex, family history, smoking, hypertension and diabetes. The middle cerebral artery (MCA) territory is the most commonly affected territory in a cerebral infarction, due to the size of the territory and the direct flow from the internal carotid artery to the middle cerebral artery, providing the easiest route for thromboembolism . (2) Hemorrhagic transformation is a complication of cerebral ischemic infarction and can significantly worsen the prognosis. The rate of hemorrhagic transformation of ischemic strokes has been variably reported, but generally over half of all cerebral infarctions develop some hemorrhagic component at some stage, while the majority (89%) are petechial hemorrhages and a minority (11%) ) hematomas. (3) Although hemorrhagic transformation can occur spontaneously, is more commonly seen in patients receiving anticoagulant treatment and even more frequently in those undergoing thrombolytic therapy, the overall rate of spontaneous hemorrhagic transformation (with hematoma) has been reported to be high as ~5%, the frequency of symptomatic hemorrhagic transformation is however much lower, between 0.6 and 3% in untreated patients and up to 6% in patients treated with intravenous tissue plasminogen activator (tPA).( 4)Acute Ischemic Stroke Imaging Non-contrast computed tomography (NCCT): NCCT of the brain remains the mainstay of imaging in the setting of an acute stroke. It is fast, cheap and easily available. Its main limitation, however, is inadequate sensitivity in the acute setting. The detection depends on the territory, on the experience of the interpreting radiologist and obviously on the time of the scan from the onset of symptoms. Whether the tissue is supplied by terminal arteries (e.g. the lenticulostriate arteries) or has a collateral supply (much of the cerebral cortex) will influence how quickly cytotoxic edema develops.(5) Detection has been shown of infarction in the MCA territory is approximately 60-70% in the first 6 hours,(6) although changes in the deep nuclei of the gray matter (especially in the lentiform nucleus) may be visible within 1 hour after occlusion up to 60% of patients. Within the first few hours, different signs are visible depending on the site of occlusion and the presence of collateral flow. Early features include: Loss of gray-white matter differentiation and hypoattenuation of deep nuclei. Cortical hypodensity with associated parenchymal swelling resulting in effacement of the gyrals. (5) Please note: this is just an example. Get a customized document from our expert writers now. Get a Custom Essay Petechial hemorrhages, as the name suggests, usually appear as tiny punctate regions of hemorrhage, often not capable of being resolved individually, but rather resulting in increased attenuation of the area on CT. In the case of secondary hematomas the hemorrhage is often patchy, widespread throughout the infarcted tissue and usually represents only a small part of the abnormal tissue.(4)