PT - JOURNAL ARTICLE AU - Joshi, M.D. AU - O'Kelly, C.J. AU - Krings, T. AU - Fiorella, D. AU - Marotta, T.R. TI - Observer Variability of an Angiographic Grading Scale Used for the Assessment of Intracranial Aneurysms Treated with Flow-Diverting Stents AID - 10.3174/ajnr.A3431 DP - 2013 Aug 01 TA - American Journal of Neuroradiology PG - 1589--1592 VI - 34 IP - 8 4099 - http://www.ajnr.org/content/34/8/1589.short 4100 - http://www.ajnr.org/content/34/8/1589.full SO - Am. J. Neuroradiol.2013 Aug 01; 34 AB - BACKGROUND AND PURPOSE: Novel angiographic grading scales for the assessment of intracranial aneurysms treated with flow-diverting stents have been recently developed because previous angiographic grading scales cannot be applied to these aneurysms. The purpose of this study was to evaluate the inter- and intraobserver variability of the novel O'Kelly Marotta grading scale, which was developed specifically for the angiographic assessment of aneurysms treated with flow-diverting stents. MATERIALS AND METHODS: Multiple raters (n = 31) from the disciplines of neuroradiology and neurosurgery were presented with pre- and posttreatment angiographic images of 14 aneurysms treated with intraluminal flow diverters. Raters were asked to classify pre- and posttreatment angiograms by using the OKM grading scale. Statistical analyses were subsequently performed with calculation of a generalized multirater κ statistic for assessment of inter- and intraobserver variability and by performing a Wilcoxon signed rank sum test for assessment of group differences. RESULTS: Variability analysis of the OKM grading scale yielded substantial (κ = 0.74) and almost perfect (κ = 0.99) inter- and intraobserver agreement, respectively, with no statistically significant differences between raters with a background of neuroradiology versus neurosurgery or attending physician versus trainee. CONCLUSIONS: The OKM grading scale for the assessment of intracranial aneurysms treated with flow-diverting stents is a reliable grading scale that can be used equally well by users of varying backgrounds and levels of training. Comparison with interobserver variability of pre-existing angiographic grading scales shows equal or better performance. OKMO'Kelly Marotta