{"product_id":"multimodal-computed-tomography-in-the-evaluation-of-acute-ischemic-stroke","title":"Multimodal computed tomography in the evaluation of acute ischemic stroke","description":"Stroke is one of the leading causes of mortality and the loss of quality life years worldwide. Ischemic stroke is a vascular disease that is characterized by insufficient flow of blood to brain tissue. In general, stroke results from the occlusion of an intracranial artery by a thrombus. Therapeutic interventions are aimed at restoring the normal circulation and limiting the extent of irreversible damage. Thus, therapies that elicit reperfusion, such as intravenous thrombolysis (IVT) and intra-arterial interventions, are of special interest. Imaging has a central role in the evaluation of acute-stroke patients. It enables the detection of intracranial hemorrhage, the approximation of the volume of reversible and irreversible ischemic changes and provides information on cerebral vasculature. These data can be used to predict the clinical outcome and the risk of hemorrhagic complications and to triage the patients to different therapeutic approaches. Multimodal computed tomography CT, especially parameters derived from CT angiography (CTA) and CT perfusion (CTP) studies, holds promise for achieving these goals with increased precision. \n\nThis thesis examined, in a retrospective, observational cohort, the utility and the predictive performance of imaging parameters derived from CTA and CTP scans obtained upon admission in the evaluation of acute (less than 3 h from the onset of the symptoms) ischemic stroke patients who received IVT during the years 2004 to 2007. The 3-month functional outcome was the main prognostic end point. The parameters studied included the Alberta Stroke Program Early CT Score (ASPECTS) that was assigned to different CTP maps and the CTP ASPECTS mismatch, the Boston Acute Stroke Imaging Scale (BASIS), the Clot Burden Score (CBS), and the location of the clot. In addition, two modified imaging parameters (M1-BASIS and CBSV) were introduced. The quality of CTP scans using scanners with detector widths of either 16 or 64 rows was also investigated. \n\nThe CTP ASPECTS parameters were found to detect reversible ischemia and to correlate with the clinical outcome. The CTP ASPECTS mismatch adequately identified the amount of potentially salvageable tissue. CBS, BASIS and the cerebral blood volume (CBV) ASPECTS scores were statistically robust and sensitive but unspecific predictors of a favorable clinical outcome. The two modified imaging parameters, CBSV and M1-BASIS, shared these same properties and appeared to provide slightly improved prognostic accuracy. The functional outcomes of an acute internal carotid artery (ICA) occlusion and\/or a proximal M1 segment of the middle cerebral artery (MCA) occlusion were typically found to be poor even if treated with IVT. A cut-point between the proximal and the distal M1 segments showed the highest accuracy in discerning favorable from poor clinical outcome. CTP scans performed using a 16-row scanner were significantly less sensitive in the detection of perfusion defects in the cranial parts of the MCA region compared with a 64-row scanner. The 16-row scans showed more uncorrected motion artifacts that resulted from periodic small-scale patient movements. \n\nOverall, the parameters derived from the multimodal CT provided added value in the evaluation of acute ischemic stroke.","brand":"Tampere University Press","offers":[{"title":"Default Title","offer_id":32447865225316,"sku":"9789514488924","price":55.95,"currency_code":"EUR","in_stock":true}],"url":"https:\/\/suomalainen-test.myshopify.com\/products\/multimodal-computed-tomography-in-the-evaluation-of-acute-ischemic-stroke","provider":"Suomalainen Test","version":"1.0","type":"link"}