RT Journal Article SR Electronic T1 Delayed Contrast-Enhanced MR Angiography for the Assessment of Internal Carotid Bulb Patency in the Context of Acute Ischemic Stroke: An Accuracy, Interrater, and Intrarater Agreement Study JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 1116 OP 1122 DO 10.3174/ajnr.A7054 VO 42 IS 6 A1 Boisseau, W. A1 Benaissa, A. A1 Fahed, R. A1 Amegnizin, J.-L. A1 Smajda, S. A1 Benadjaoud, S. A1 Benadjaoud, A.M. A1 Saint-Val, L. A1 Alias, Q. A1 Iorio, P. A1 Yang, S. A1 Zuber, K. A1 Kalsoum, E. A1 Hodel, J. YR 2021 UL http://www.ajnr.org/content/42/6/1116.abstract AB BACKGROUND AND PURPOSE: CTA has shown limited accuracy and reliability in distinguishing tandem occlusions and pseudo-occlusions on initial acute stroke imaging. The utility of early and delayed contrast-enhanced MRA in this setting is unknown. We aimed to assess the accuracy and reliability of early and delayed contrast-enhanced MRA for carotid bulb patency in patients with acute ischemic stroke.MATERIALS AND METHODS: We retrospectively reviewed patients who had ICA occlusion and underwent thrombectomy with preprocedural early and delayed contrast-enhanced MRA in a single comprehensive stroke center. During 2 sessions, 10 raters independently assessed 32 cases with early contrast-enhanced MRA (with an additional delayed contrast-enhanced MRA sequence during the second reading session). Their judgments were compared with DSA as a reference standard. Accuracy and interrater agreement were measured. Five raters undertook a third reading session to assess intrarater agreement.RESULTS: Accuracy for the assessment of carotid bulb patency with early contrast-enhanced MRA was limited (69%; 95% CI, 59%–79%), with moderate interrater agreement (κ = 0.42; 95% CI, 0.27–0.55). The second reading with an additional delayed contrast-enhanced MRA sequence improved both accuracy (82%; 95% CI, 73%–91%; P < .001) (raters corrected 43%–77% of incorrect diagnoses with early contrast-enhanced MRA alone; mean = 59%) and interrater agreement (κ = 0.56; 95% CI, 0.41–0.73; P = .07). Intrarater agreement was almost perfect, substantial, and moderate for 3, 1, and 1 raters.CONCLUSIONS: Early contrast-enhanced MRA has limited accuracy and repeatability for the evaluation of carotid bulb patency in acute ischemic stroke. The additional delayed contrast-enhanced MRA sequence may improve accuracy and reliability.AISacute ischemic strokeCEcontrast-enhancedPOpseudo-occlusion