Grant Mair1, Elena V Boyd1, Francesca M Chappell1, Rüdiger von Kummer1, Richard I Lindley1, Peter Sandercock1, Joanna M Wardlaw2. 1. From the Division of Neuroimaging Sciences, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom (G.M., F.M.C., P.S., J.M.W.); Department of Radiology, Northwick Park Hospital, Harrow, United Kingdom (E.V.B.); Department of Neuroradiology, Dresden University Stroke Centre, University Hospital, Dresden, Germany (R.v.K.); and Westmead Hospital Clinical School and The George Institute for Global Health, University of Sydney, Sydney, New South Wales, Australia (R.I.L.). 2. From the Division of Neuroimaging Sciences, University of Edinburgh, Western General Hospital, Edinburgh, United Kingdom (G.M., F.M.C., P.S., J.M.W.); Department of Radiology, Northwick Park Hospital, Harrow, United Kingdom (E.V.B.); Department of Neuroradiology, Dresden University Stroke Centre, University Hospital, Dresden, Germany (R.v.K.); and Westmead Hospital Clinical School and The George Institute for Global Health, University of Sydney, Sydney, New South Wales, Australia (R.I.L.). joanna.wardlaw@ed.ac.uk.
Abstract
BACKGROUND AND PURPOSE: In acute ischemic stroke, the hyperdense artery sign (HAS) on noncontrast computed tomography (CT) is thought to represent intraluminal thrombus and, therefore, is a surrogate of arterial obstruction. We sought to assess the accuracy of HAS as a marker of arterial obstruction by thrombus. METHODS: The Third International Stroke Trial (IST-3) was a randomized controlled trial testing the use of intravenous thrombolysis for acute ischemic stroke in patients who did not clearly meet the prevailing license criteria. Some participating IST-3 centers routinely performed CT or MR angiography at baseline. One reader assessed all relevant scans independently, blinded to all other data; we checked observer reliability. We combined IST-3 data with a systematic review and meta-analysis of all studies that assessed the accuracy of HAS using angiography (any modality). RESULTS: IST-3 had 273 patients with baseline CT or MR angiography and was the largest study of HAS accuracy. The meta-analysis (n=902+273=1175, including IST-3) found sensitivity and specificity of HAS for arterial obstruction on angiography to be 52% and 95%, respectively. HAS was more commonly identified in proximal than distal arteries (47% versus 37%; P=0.015), and its sensitivity increased with thinner CT slices (r=-0.73; P=0.001). Neither extent of obstruction nor time after stroke influenced HAS accuracy. CONCLUSIONS: When present in acute ischemic stroke, HAS indicates a high likelihood of arterial obstruction, but its absence indicates only a 50/50 chance of normal arterial patency. Thin-slice CT improves sensitivity of HAS detection. CLINICAL TRIAL REGISTRATION URL: http://www.controlled-trials.com/ISRCTN25765518. Unique identifier: ISRCTN25765518.
BACKGROUND AND PURPOSE: In acute ischemic stroke, the hyperdense artery sign (HAS) on noncontrast computed tomography (CT) is thought to represent intraluminal thrombus and, therefore, is a surrogate of arterial obstruction. We sought to assess the accuracy of HAS as a marker of arterial obstruction by thrombus. METHODS: The Third International Stroke Trial (IST-3) was a randomized controlled trial testing the use of intravenous thrombolysis for acute ischemic stroke in patients who did not clearly meet the prevailing license criteria. Some participating IST-3 centers routinely performed CT or MR angiography at baseline. One reader assessed all relevant scans independently, blinded to all other data; we checked observer reliability. We combined IST-3 data with a systematic review and meta-analysis of all studies that assessed the accuracy of HAS using angiography (any modality). RESULTS: IST-3 had 273 patients with baseline CT or MR angiography and was the largest study of HAS accuracy. The meta-analysis (n=902+273=1175, including IST-3) found sensitivity and specificity of HAS for arterial obstruction on angiography to be 52% and 95%, respectively. HAS was more commonly identified in proximal than distal arteries (47% versus 37%; P=0.015), and its sensitivity increased with thinner CT slices (r=-0.73; P=0.001). Neither extent of obstruction nor time after stroke influenced HAS accuracy. CONCLUSIONS: When present in acute ischemic stroke, HAS indicates a high likelihood of arterial obstruction, but its absence indicates only a 50/50 chance of normal arterial patency. Thin-slice CT improves sensitivity of HAS detection. CLINICAL TRIAL REGISTRATION URL: http://www.controlled-trials.com/ISRCTN25765518. Unique identifier: ISRCTN25765518.
Authors: E Assouline; K Benziane; D Reizine; J P Guichard; F Pico; J J Merland; M G Bousser; H Chabriat Journal: Cerebrovasc Dis Date: 2005-05-30 Impact factor: 2.762
Authors: Peter D Schellinger; Julio A Chalela; Dong-Wha Kang; Lawrence L Latour; Steven Warach Journal: AJNR Am J Neuroradiol Date: 2005-03 Impact factor: 3.825
Authors: R von Kummer; U Meyding-Lamadé; M Forsting; L Rosin; K Rieke; W Hacke; K Sartor Journal: AJNR Am J Neuroradiol Date: 1994-01 Impact factor: 3.825
Authors: Peter Sandercock; Joanna M Wardlaw; Richard I Lindley; Martin Dennis; Geoff Cohen; Gordon Murray; Karen Innes; Graham Venables; Anna Czlonkowska; Adam Kobayashi; Stefano Ricci; Veronica Murray; Eivind Berge; Karsten Bruins Slot; Graeme J Hankey; Manuel Correia; Andre Peeters; Karl Matz; Phillippe Lyrer; Gord Gubitz; Stephen J Phillips; Antonio Arauz Journal: Lancet Date: 2012-05-23 Impact factor: 79.321