Catarino, José Carlos MotaViegas, InêsRodrigues, JoanaPinto, MartaBota, GonçaloCravo, FranciscoLúcio, FilipaFaísca, Pedro2019Catarino , J C M , Viegas , I , Rodrigues , J , Pinto , M , Bota , G , Cravo , F , Lúcio , F & Faísca , P 2019 , ' Quantifying myocardial fibrosis on murine model using ImageJ ' , Revista Lusófona de Ciência e Medicina Veterinária . https://doi.org/10.60543/rlcmv.v9i0.66391646-8805Revista Lusófona de Ciência e Medicina VeterináriaQuantification of histological images is a task often required in biomedical research. Many of the methods used are time-consuming, difficult to replicate and subjective. This work aimed to describe and validate a more objective, reproducible and easy to perform methodology to measure murine heart fibrosis, using ImageJ software. For this matter, a macro was created and validated for its intra and inter-observational reproducibility. No significant differences were found between the results obtained manually and with the macro (p> 0.05). Regarding the interobserver variability, the macro proved to be a less variable method by presenting higher correlation coefficients between observers when compared with the manual measurement. With these results, we were able to define and describe a methodology that outputs objective and replicable results in a less laborious way.application/pdfengopenAccessIMAGEJVETERINÁRIAMEDICINA VETERINÁRIAFIBROSECORAÇÃOMORFOMETRIAPATOLOGIA EXPERIMENTALFIBROSISHEARTVETERINARY MEDICINEMORPHOMETRYEXPERIMENTAL PATHOLOGYarticlehttps://doi.org/10.60543/rlcmv.v9i0.6639