@article {DekosterPP202, author = {Kaat Dekoster and Sofie Van Den Broucke and Tatjana Decaesteker and Nathalie Berghen and Jens Wouters and Rik Lories and Peter Hoet and Jeroen Vanoirbeek and Greetje Vande Velde}, title = {Longitudinal in vivo {\textmu}CT for characterization of acute exacerbations in a pulmonary fibrosis mouse model}, volume = {5}, number = {suppl 2}, elocation-id = {PP202}, year = {2019}, doi = {10.1183/23120541.lungscienceconference-2019.PP202}, publisher = {European Respiratory Society}, abstract = {Pulmonary fibrosis is a life-threatening condition for which effective treatment is still lacking. To improve preclinical research, we introduced an in vivo {\textmu}CT protocol to repeatedly assess lung fibrosis progression in a silica-induced mouse model. {\textmu}CT-derived biomarkers allow longitudinal assessment of a lung fibrosis model in free-breathing animals and are therefore highly relevant to evaluate early and acute exacerbations.Mice were endotracheally instilled with crystalline silica or saline and scanned bi-weekly for 15 weeks with respiratory gated high-resolution low-dose {\textmu}CT. To evaluate the inflammatory and fibrotic phases of disease onset and progress, we used three lung biomarkers derived from the scans. At four different time points after instillation (day 7, 35, 63 and 105) lung function measurements, cellular, biochemical and histological analysis were obtained and cross-validated with the imaging data.Silica instillation resulted in a significant increase of non-aerated lung volume (corresponding with inflammatory and fibrotic processes) and total lung volume (corresponding to compensatory host response). The aerated lung volume decreased to gradually increase again, indicating an acute inflammatory response. Imaging results were confirmed by a significantly decreased tiffeneau index (d35 and d63), increased neutrophilic inflammation (d7 - d105), increased collagen content (d35 - d105) and increased granuloma formation (d35 - 105).Our findings indicate that {\textmu}CT is an excellent technique to longitudinally evaluate pulmonary fibrosis in mice, a novel approach that allows evaluation of acute exacerbations, disease progression and stabilization over several weeks.FootnotesCite this article as: ERJ Open Research 2019; 5 : Suppl. 2, PP202.This is an ERS Lung Science Conference abstract. No full-text version is available. Further material to accompany this conference is available at www.ers-education.org (ERS member access only).}, URL = {https://openres.ersjournals.com/content/5/suppl_2/PP202}, eprint = {https://openres.ersjournals.com/content}, journal = {ERJ Open Research} }