Mu, Changqing

ABSTRACT Reliable assessment of infarct severity is essential in experimental stroke research, yet commonly used approaches such as 2,3,5‐triphenyltetrazolium chloride (TTC) staining and magnetic resonance imaging require additional tissue processing, specialized equipment, or substantial time and cost. In this study, we developed and validated a rapid visual Infarct Score to determine infarct volume and evaluate neuroprotective efficacy in rat middle cerebral artery occlusion (MCAO) models. A retrospective analysis was performed using data from 315 male Sprague–Dawley rats, including TTC‐derived infarct volume, visual Infarct Score, neurological deficit scores, and body weight changes. The Infarct Score demonstrated the strongest correlation with infarct volume among individual indicators in both nontreatment (Rho = 0.71) and treatment cohorts (Rho = 0.68). We further developed a Comprehensive Score by integrating the Infarct Score with the Longa 5‐point score at 48 h, which showed the highest overall correlation with infarct volume (Rho = 0.75 in both cohorts) and strong discrimination of infarct severity (AUC = 0.90). Interrater reliability analysis demonstrated excellent agreement among independent raters (intraclass correlation coefficient = 0.89; Kendall's W = 0.83, both p < 0.001). Neuroprotective interventions, including therapeutic hypothermia, nitroglycerin, and remote ischemic conditioning combined with physical exercise, significantly reduced infarct volume, Infarct Score, Comprehensive Score, neurological deficits, and weight loss. These findings indicate that the Infarct Score offers a rapid, practical, and cost‐effective method for infarct assessment, whereas the Comprehensive Score further improves the predictive accuracy and may serve as a useful tool for evaluating stroke severity and treatment outcomes in preclinical studies.