BACKGROUND AND PURPOSE: Analogous to the CT hyperattenuated vessel sign (HMCAS), MR imaging may show hypo- or hyperintense vessels in acute ischemic stroke (AIS) patients. We assessed the diagnostic and prognostic strength of early MR imaging vessel signs in AIS patients treated with intravenous thrombolysis (IVT) within 3 hours of the onset of symptoms. METHODS: We studied AIS patients both treated with IVT and stroke MR imaged within 3 hours of the onset of symptoms and at 2 hours and 24 hours after treatment. We assessed the presence or absence of early vessel signs (hyperintense fluid-attenuated inversion recovery sign [FLAIR HVS]; gradient-echo susceptibility vessel sign [GRE SVS]) compared with a combined MR angiography/perfusion-weighted imaging reference and their strength for predicting clinical outcome (favorable vs. poor, independent vs. dependent, or dead, death), recanalization (by clot composition and flow), and hemorrhage in uni- and multivariate analysis. RESULTS: Fifty-six patients (age range, 76 years ± 13 years; median National Institutes of Health stroke scale score [NIHSSS], 11) met the inclusion criteria. Forty-four patients (78.6%) had a vessel occlusion at baseline; 22 of them (50%) recanalized. Nineteen patients (33.9%) suffered some form of intracranial hemorrhage (ICH), 24 patients (42.9%) had an independent outcome, 18 patients (32.1%) a favorable outcome, and 14 patients died. Compared with our combined reference for vessel status PWI/MRA, the sensitivities of CT HMCAS, FLAIR HVS, and GRE SVS were 40%, 66%, and 34%, respectively, and improved during the hours that followed. Localization was accurately reflected by FLAIR HVS but not by GRE SVS. Only NIHSSS and age were independent predictors for recanalization and all clinical outcomes in multiple logistic regression analysis. CONCLUSION: Although early vessel signs can be helpful in the diagnosis of intravascular disease, they do not independently predict recanalization, ICH, or any of the three clinical outcomes in a multivariate logistic regression model. Thrombus composition as reflected by signal intensity characteristics on GRE and FLAIR does not predict the therapeutic effect of IVT.

Diagnostic and prognostic value of early MR imaging vessel signs in hyperacute stroke patients imaged <3 hours and treated with recombinant tissue plasminogen activator

Purpose There is ongoing debate on which method of perfusion computed tomography (PCT) evaluation in ischemic stroke is the most appropriate for improved selection of patients for endovascular treatment. We sought to test different assessment methods for inter-rater reliability. Methods Twenty-six patients were enrolled prospectively before endovascular therapy for acute anterior circulation ischemic stroke. Three raters experienced in stroke imaging and blinded to other imaging and clinical information independently analyzed 22 technically successful PCT scans according to 3 prespecified assessment methods applied to cerebral blood flow (CBF)/cerebral blood volume (CBV) and time-to-peak (TTP) maps: (1) visual mismatch estimate (VME), (2) Alberta Stroke Program Early CT Score perfusion method (ASPECTS-PCT), and (3) quantitative perfusion ratios (qPRs): R CBF , R CBV , R TTP . Inter-rater agreement was assessed with Cohen's kappa, intraclass correlation coefficients (ICC), Bland–Altman plots, and global and descriptive statistics. Results Significant differences between raters were found with VME and ASPECTS-PCT ( P P  = .03). Inter-rater agreement for VME was at best moderate by kappa statistics (.51); moderate by ICC for all parametric maps of ASPECTS-PCT (.56-.62), strong for R TTP (.76), and excellent for R CBF (.92) and R CBV (.86). Pairwise comparisons revealed less scattering of individual values with qPRs and less deviation of mean differences from 0, suggesting minor systematic deviation by any 1 rater as compared with VME or ASPECTS-PCT. Conclusion PCT evaluation methods used before endovascular therapy for acute anterior circulation stroke are subject to substantial inter-rater disagreement. QPRs in PCT evaluation had better inter-rater reliability than the often used VME and ASPECTS-PCT assessment.

Inter-rater Agreement in Three Perfusion-Computed Tomography Evaluation Methods before Endovascular Therapy for Acute Ischemic Stroke.

Max Wintermark, MD, MAS; Gregory W. Albers, MD; Joseph P. Broderick, MD; Andrew M. Demchuk, MD; Jochen B. Fiebach, MD; Jens Fiehler, MD; James C. Grotta, MD; Gary Houser; Tudor G. Jovin, MD; Kennedy R. Lees, MD; Michael H. Lev, MD; David S. Liebeskind, MD; Marie Luby, PhD; Keith W. Muir, MD; Mark W. Parsons, MD, PhD; Rüdiger von Kummer, MD; Joanna M. Wardlaw, MD; Ona Wu, PhD; Albert J. Yoo, MD; Andrei V. Alexandrov, MD; Jeffry R. Alger, MD, PhD; Richard I. Aviv, MD; Roland Bammer, PhD; Jean-Claude Baron, MD, ScD; Fernando Calamante, PhD; Bruce C.V. Campbell, MD, PhD; Trevor C. Carpenter, PhD; Søren Christensen, PhD; William A. Copen, MD; Colin P. Derdeyn, MD; E. Clarke Haley Jr, MD; Pooja Khatri, MD; Kohsuke Kudo, MD, PhD; Maarten G. Lansberg, MD, PhD; Lawrence L. Latour, PhD; Ting-Yim Lee, MD; Richard Leigh, MD; Weili Lin, PhD; Patrick Lyden, MD; Grant Mair, MD; Bijoy K. Menon, MD; Patrik Michel, MD; Robert Mikulik, MD, PhD; Raul G. Nogueira, MD; Leif Østergaard, MD, PhD; Salvador Pedraza, MD; Christian H. Riedel, MD; Howard A. Rowley, MD; Pina C. Sanelli, MD, MPH; Makoto Sasaki, MD, PhD; Jeffrey L. Saver, MD; Pamela W. Schaefer, MD; Peter D. Schellinger, MD; Georgios Tsivgoulis, MD; Lawrence R. Wechsler, MD; Philip M. White, MD; Greg Zaharchuk, MD, PhD; Osama O. Zaidat, MD; Stephen M. Davis, MD; Geoffrey A. Donnan, MD; Anthony J. Furlan, MD; Werner Hacke, MD, PhD; Dong-Wha Kang, MD, PhD; Chelsea Kidwell, MD; Vincent N. Thijs, MD, PhD; Götz Thomalla, MD, PhD; Steven J. Warach, MD, PhD; for the Stroke Imaging Research (STIR) and Virtual International Stroke Trials Archive (VISTA)-Imaging Investigators

Acute Stroke Imaging Research Roadmap II Special Reports

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Acute Stroke Imaging Research Roadmap II Special Reports