More Is Better: Rater Consensus on Lesion Outline in Acute Stroke Improves Predictive Models

¹Department of Neuroradiology, Aarhus University Hospital, Aarhus, Aarhus C, Denmark

Accurate and reliable delineation of the final infarct in acute ischemic stroke is critical as volume or location of the lesion is typically used as surrogate outcome in clinical stroke trials. Here we study the effect of consensus in outlining the final infarct on a FLAIR image among 9 expert neuroradiologists on the performance of models predicting the final infarct using acute MRI. Predictive models are trained and tested using different degrees of consensus. Our results show that the large variability in lesion delineation effects the models substantially. In particular, complete consensus of the 9 raters provides the highest performance and consequently, multiple rating or standardized lesion definitions should be applied.