Grant Mair1, Awad Alzahrani2, Richard I Lindley3,4, Peter A G Sandercock2, Joanna M Wardlaw5. 1. Edinburgh Imaging, and UK Dementia Research Institute at the University of Edinburgh and Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK. grant.mair@ed.ac.uk. 2. Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK. 3. Westmead Applied Research Centre, University of Sydney, Sydney, Australia. 4. The George Institute for Global Health, Newtown, Australia. 5. Edinburgh Imaging, and UK Dementia Research Institute at the University of Edinburgh and Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
Abstract
PURPOSE: CT attenuation of ischemic brain reduces with time after stroke onset. We aimed to quantify this relationship and test the feasibility and accuracy of estimating stroke onset time using only CT attenuation of visible ischemic lesions, the CT-Clock Tool. METHODS: We selected CT scans with ischemic lesions representing a range of stroke-onset-to-scan times (elapsed time) from a well-defined stroke trial. We measured the attenuation of ischemic lesions and contralateral normal brain to derive attenuation ratio. We assigned scans to development (75%) or test (25%) datasets. We plotted the relationship between attenuation ratio and elapsed time in the development dataset and derived a best-fit curve. We calculated estimated time in the test dataset using only the attenuation ratio curve. We compared estimated time to elapsed time and derived absolute error for estimated time. We assessed area under the receiver operating characteristic (AUROC) curve for identifying scans ≤ 4.5 h elapsed time. RESULTS: We included 342 scans from 200 patients (41% male, median age 83 years). Elapsed time range: 22 min to 36 days. Estimation errors were least at early elapsed times (r = 0.82, p < 0.0001): median absolute error was 23, 106, 1030 and 1933 min for scans acquired ≤ 3, > 3-9, > 9-30 and > 30 h from stroke onset, respectively. AUROC was high at 0.955. CONCLUSIONS: It is feasible to accurately estimate stroke onset time using simple attenuation measures of ischemic brain. Our method was most accurate 0-9 h from onset and may be useful for treatment eligibility assessment, especially where imaging resources are limited.
PURPOSE: CT attenuation of ischemic brain reduces with time after stroke onset. We aimed to quantify this relationship and test the feasibility and accuracy of estimating stroke onset time using only CT attenuation of visible ischemic lesions, the CT-Clock Tool. METHODS: We selected CT scans with ischemic lesions representing a range of stroke-onset-to-scan times (elapsed time) from a well-defined stroke trial. We measured the attenuation of ischemic lesions and contralateral normal brain to derive attenuation ratio. We assigned scans to development (75%) or test (25%) datasets. We plotted the relationship between attenuation ratio and elapsed time in the development dataset and derived a best-fit curve. We calculated estimated time in the test dataset using only the attenuation ratio curve. We compared estimated time to elapsed time and derived absolute error for estimated time. We assessed area under the receiver operating characteristic (AUROC) curve for identifying scans ≤ 4.5 h elapsed time. RESULTS: We included 342 scans from 200 patients (41% male, median age 83 years). Elapsed time range: 22 min to 36 days. Estimation errors were least at early elapsed times (r = 0.82, p < 0.0001): median absolute error was 23, 106, 1030 and 1933 min for scans acquired ≤ 3, > 3-9, > 9-30 and > 30 h from stroke onset, respectively. AUROC was high at 0.955. CONCLUSIONS: It is feasible to accurately estimate stroke onset time using simple attenuation measures of ischemic brain. Our method was most accurate 0-9 h from onset and may be useful for treatment eligibility assessment, especially where imaging resources are limited.
Authors: Gregory W Albers; Michael P Marks; Stephanie Kemp; Soren Christensen; Jenny P Tsai; Santiago Ortega-Gutierrez; Ryan A McTaggart; Michel T Torbey; May Kim-Tenser; Thabele Leslie-Mazwi; Amrou Sarraj; Scott E Kasner; Sameer A Ansari; Sharon D Yeatts; Scott Hamilton; Michael Mlynash; Jeremy J Heit; Greg Zaharchuk; Sun Kim; Janice Carrozzella; Yuko Y Palesch; Andrew M Demchuk; Roland Bammer; Philip W Lavori; Joseph P Broderick; Maarten G Lansberg Journal: N Engl J Med Date: 2018-01-24 Impact factor: 91.245
Authors: Raul G Nogueira; Ashutosh P Jadhav; Diogo C Haussen; Alain Bonafe; Ronald F Budzik; Parita Bhuva; Dileep R Yavagal; Marc Ribo; Christophe Cognard; Ricardo A Hanel; Cathy A Sila; Ameer E Hassan; Monica Millan; Elad I Levy; Peter Mitchell; Michael Chen; Joey D English; Qaisar A Shah; Frank L Silver; Vitor M Pereira; Brijesh P Mehta; Blaise W Baxter; Michael G Abraham; Pedro Cardona; Erol Veznedaroglu; Frank R Hellinger; Lei Feng; Jawad F Kirmani; Demetrius K Lopes; Brian T Jankowitz; Michael R Frankel; Vincent Costalat; Nirav A Vora; Albert J Yoo; Amer M Malik; Anthony J Furlan; Marta Rubiera; Amin Aghaebrahim; Jean-Marc Olivot; Wondwossen G Tekle; Ryan Shields; Todd Graves; Roger J Lewis; Wade S Smith; David S Liebeskind; Jeffrey L Saver; Tudor G Jovin Journal: N Engl J Med Date: 2017-11-11 Impact factor: 91.245
Authors: Henry Ma; Bruce C V Campbell; Mark W Parsons; Leonid Churilov; Christopher R Levi; Chung Hsu; Timothy J Kleinig; Tissa Wijeratne; Sami Curtze; Helen M Dewey; Ferdinand Miteff; Chon-Haw Tsai; Jiunn-Tay Lee; Thanh G Phan; Neil Mahant; Mu-Chien Sun; Martin Krause; Jonathan Sturm; Rohan Grimley; Chih-Hung Chen; Chaur-Jong Hu; Andrew A Wong; Deborah Field; Yu Sun; P Alan Barber; Arman Sabet; Jim Jannes; Jiann-Shing Jeng; Benjamin Clissold; Romesh Markus; Ching-Huang Lin; Li-Ming Lien; Christopher F Bladin; Søren Christensen; Nawaf Yassi; Gagan Sharma; Andrew Bivard; Patricia M Desmond; Bernard Yan; Peter J Mitchell; Vincent Thijs; Leeanne Carey; Atte Meretoja; Stephen M Davis; Geoffrey A Donnan Journal: N Engl J Med Date: 2019-05-09 Impact factor: 91.245
Authors: Thomas Kucinski; Ole Väterlein; Volkmar Glauche; Jens Fiehler; Ernst Klotz; Bernd Eckert; Christoph Koch; Joachim Röther; Hermann Zeumer Journal: Stroke Date: 2002-07 Impact factor: 7.914
Authors: Joanna M Wardlaw; Rüdiger von Kummer; Andrew J Farrall; Francesca M Chappell; Michael Hill; David Perry Journal: PLoS One Date: 2010-12-30 Impact factor: 3.240
Authors: Peter Sandercock; Richard Lindley; Joanna Wardlaw; Martin Dennis; Steff Lewis; Graham Venables; Adam Kobayashi; Anna Czlonkowska; Eivind Berge; Karsten Bruins Slot; Veronica Murray; Andre Peeters; Graeme Hankey; Karl Matz; Michael Brainin; Stefano Ricci; Maria Grazia Celani; Enrico Righetti; Teresa Cantisani; Gord Gubitz; Steve Phillips; Antonio Arauz; Kameshwar Prasad; Manuel Correia; Phillippe Lyrer Journal: Trials Date: 2008-06-17 Impact factor: 2.279