Laura Carrero-Gonzalez1,2, Thomas Kaulisch1, Jesus Ruiz-Cabello2,3, Detlef Stiller1, Ignacio Rodriguez2,3
1Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Baden-Wrttemberg, Germany; 2Universidad Complutense de Madrid, Madrid, Spain; 3CIBER de Enfermedades Respiratorias, Madrid, Spain
Apparent diffusion coefficient (ADC) reflects changes in lung microstructure and it is used as a detector of lung diseases. Instillation of elastase in the lung produces emphysema, which is characterized by higher airspaces, higher compliance and higher residual volume compared to healthy tissue. It has been proved the feasibility of instilling elastase in only one lung using the other lung of the rat as an internal control. ADC values from elastase-treated and healthy lungs showed significant differences at the end of the expiration, but not during a full-inspiration breath-hold (23mbar). A special ventilation protocol reduces the effect on the ADC due to the different diffusivity of mixtures with either different gases composition or different gases concentration.