Defining malignant cerebellar infarction: a systematic review of outcome definitions and quantitative imaging thresholds

Protocol for a PROSPERO-registered systematic review (CRD420261553314) of how malignant (space-occupying) cerebellar infarction has been operationally defined, and of the quantitative imaging thresholds proposed to predict it. The review maps each study's definition to a six-category taxonomy (D1-D6), reports the incidence of the target condition within each category, tabulates every proposed threshold with its measurement method and discrimination, and recomputes positive predictive values at standardised prevalences of 15%, 25% and 35% to test whether threshold discordance is explained by differences in prevalence rather than by measurement error. Protocol version 1.1, 28 October 2026. Registration record: CRD420261553314. Contact: Chunyu Tan, Zhujiang Hospital, Southern Medical University.