BACKGROUND: The evaluation of DWI/FLAIR mismatch in ischaemic stroke patients with unknown, time from onset can determine the treatment strategy. This approach is based on, visual assessment and may be subject to insufficient inter-rater agreement. OBJECTIVE: To compare the inter-rater agreement of visual evaluation of FLAIR MRI and proposed region of interest (ROI) semiquantitative method in large vessel occlusion (LVO) strokes. METHODS: Five readers have analysed MRIs of 104 patients obtained within six hours of the onset of stroke symptoms resulting from LVO visually and semi-quantitatively. For the semiquantitative analysis, a ROI method was used to obtain relative signal intensity compared to the unaffected side. Cut-off values of 1.15 and 1.10 were tested. The analysis yielded FLAIR-positive (abnormal) and negative (normal) findings. Percentage agreement and Fleiss kappa coefficients were calculated. RESULTS: The visual agreement of 5/5 readers and ≥ 4/5 readers occurred in 31% and 59% of cases respectively. Semi-quantitative evaluation using a cut-off value of 1.15 increased the agreements to 67% and 88% respectively. The agreement of visual evaluation was fair. The semi-quantitative method utilising the cut-off of 1.15 had moderate agreement although it increased the number of FLAIR-negative results compared to the visual evaluation. A low cut-off value of 1.10 didn't improve the agreement significantly. CONCLUSION: The inter-rater agreement of visual evaluation of FLAIR in patients with short-duration large vessel occlusion stroke was fair. The high cut-off value of semiquantitative evaluation increased the agreement although it changed the proportion of FLAIR positive and negative results.

Department of Mathematical Analysis and Applications of Mathematics Faculty of Science Palacky University Olomouc Czech Republic

Department of Neurology Palacky University and University Hospital Olomouc Czech Republic

Department of Radiology Palacky University and University Hospital Olomouc Czech Republic

Faculty of Health Sciences Palacky University Olomouc Czech Republic

See more in PubMed

Powers W.J., Rabinstein A.A., Ackerson T., Adeoye O.M., Bambakidis N.C., Becker K., Biller J., Brown M., Demaerschalk B.M., Hoh B., Jauch E.C., Kidwell C.S., Leslie-Mazwi T.M., Ovbiagele B., Scott P.A., Sheth K.N., Southerland A.M., Summers D.V., Tirschwell D.L. on behalf of the American Heart Association Stroke Council, Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2019;50 doi: 10.1161/STR.0000000000000211. PubMed DOI

Galinovic I., Puig J., Neeb L., Guibernau J., Kemmling A., Siemonsen S., Pedraza S., Cheng B., Thomalla G., Fiehler J., Fiebach J.B. Visual and region of interest–based inter-rater agreement in the assessment of the diffusion-weighted imaging– fluid-attenuated inversion recovery mismatch. Stroke. 2014;45:1170–1172. doi: 10.1161/STROKEAHA.113.002661. PubMed DOI

Thomalla G., Cheng B., Ebinger M., Hao Q., Tourdias T., Wu O., Kim J.S., Breuer L., Singer O.C., Warach S., Christensen S., Treszl A., Forkert N.D., Galinovic I., Rosenkranz M., Engelhorn T., Köhrmann M., Endres M., Kang D.-W., Dousset V., Sorensen A.G., Liebeskind D.S., Fiebach J.B., Fiehler J., Gerloff C. STIR and VISTA Imaging Investigators, DWI-FLAIR mismatch for the identification of patients with acute ischaemic stroke within 4·5h of symptom onset (PRE-FLAIR): a multicentre observational study. Lancet Neurol. 2011;10:978–986. doi: 10.1016/S1474-4422(11)70192-2. PubMed DOI

Fahed R., Lecler A., Sabben C., Khoury N., Ducroux C., Chalumeau V., Botta D., Kalsoum E., Boisseau W., Duron L., Cabral D., Koskas P., Benaïssa A., Koulakian H., Obadia M., Maïer B., Weisenburger-Lile D., Lapergue B., Wang A., Redjem H., Ciccio G., Smajda S., Desilles J.-P., Mazighi M., Ben Maacha M., Akkari I., Zuber K., Blanc R., Raymond J., Piotin M. DWI-ASPECTS (Diffusion-Weighted Imaging–Alberta Stroke Program Early Computed Tomography Scores) and DWI-FLAIR (Diffusion-Weighted Imaging–Fluid Attenuated Inversion Recovery) Mismatch in Thrombectomy Candidates: An Intrarater and Interrater Agreement Study. Stroke. 2018;49:223–227. doi: 10.1161/STROKEAHA.117.019508. PubMed DOI

Cheng B., Brinkmann M., Forkert N.D., Treszl A., Ebinger M., Köhrmann M., Wu O., Kang D.-W., Liebeskind D.S., Tourdias T., Singer O.C., Christensen S., Luby M., Warach S., Fiehler J., Fiebach J.B., Gerloff C., Thomalla G. Quantitative Measurements of Relative Fluid-Attenuated Inversion Recovery (FLAIR) Signal Intensities in Acute Stroke for the Prediction of Time from Symptom Onset. J. Cereb. Blood Flow. Metab. 2013;33:76–84. doi: 10.1038/jcbfm.2012.129. PubMed DOI PMC

Kim Y., Luby M., Burkett N.-S., Norato G., Leigh R., Wright C.B., Kern K.C., Hsia A.W., Lynch J.K., Adil M.M., Latour L.L. Fluid-attenuated inversion recovery hyperintense ischemic stroke predicts less favorable 90-day outcome after intravenous thrombolysis. Cereb. Dis. 2021;50:738–745. doi: 10.1159/000517241. PubMed DOI PMC

Song S.S., Latour L.L., Ritter C.H., Wu O., Tighiouart M., Hernandez D.A., Ku K.D., Luby M., Warach S. A pragmatic approach using magnetic resonance imaging to treat ischemic strokes of unknown onset time in a thrombolytic trial. Stroke. 2012;43:2331–2335. doi: 10.1161/STROKEAHA.111.630947. PubMed DOI PMC

Schwamm L.H., Wu O., Song S.S., Latour L.L., Ford A.L., Hsia A.W., Muzikansky A., Betensky R.A., Yoo A.J., Lev M.H., Boulouis G., Lauer A., Cougo P., Copen W.A., Harris G.J., Warach S. Intravenous thrombolysis in unwitnessed stroke onset: MR WITNESS trial results. Ann. Neurol. 2018;83:980–993. doi: 10.1002/ana.25235. PubMed DOI PMC

Silva G.S., Lima F.O., Camargo E.C.S., Smith W.S., Singhal A.B., Greer D.M., Ay H., Lev M.H., Harris G.J., Halpern E.F., Sonni S., Koroshetz W., Furie K.L. Wake-up stroke: clinical and neuroimaging characteristics. Cereb. Dis. 2010;29:336–342. doi: 10.1159/000278929. PubMed DOI PMC

Wouters A., Dupont P., Norrving B., Laage R., Thomalla G., Albers G.W., Thijs V., Lemmens R. Prediction of Stroke Onset Is Improved by Relative Fluid-Attenuated Inversion Recovery and Perfusion Imaging Compared to the Visual Diffusion-Weighted Imaging/Fluid-Attenuated Inversion Recovery Mismatch. Stroke. 2016;47:2559–2564. doi: 10.1161/STROKEAHA.116.013903. PubMed DOI

Petkova M., Rodrigo S., Lamy C., Oppenheim G., Touzé E., Mas J.-L., Méder J.-F., Oppenheim C. MR imaging helps predict time from symptom onset in patients with acute stroke: implications for patients with unknown onset time. Radiology. 2010;257:782–792. doi: 10.1148/radiol.10100461. PubMed DOI

Ebinger M., Galinovic I., Rozanski M., Brunecker P., Endres M., Fiebach J.B. Fluid-attenuated inversion recovery evolution within 12 h from stroke onset: a reliable tissue clock? Stroke. 2010;41:250–255. doi: 10.1161/STROKEAHA.109.568410. PubMed DOI

Lee H., Lee E.-J., Ham S., Lee H.-B., Lee J.S., Kwon S.U., Kim J.S., Kim N., Kang D.-W. Machine learning approach to identify stroke within 4.5 h. Stroke. 2020;51:860–866. doi: 10.1161/STROKEAHA.119.027611. PubMed DOI

Zhu H., Jiang L., Zhang H., Luo L., Chen Y., Chen Y. An automatic machine learning approach for ischemic stroke onset time identification based on DWI and FLAIR imaging. NeuroImage: Clin. 2021;31 doi: 10.1016/j.nicl.2021.102744. PubMed DOI PMC