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Lung morphometry and aerosol deposition in animal models

The laboratory has developed an in-situ MRI technique to measure airway morphometry along with an MRI-based method to quantify the spatial distribution of deposited particles in rodent lungs. The technique uses the change in signal decayrate (R 2 *), due to the presence of iron oxide particles, to quantify deposition. We showed that R 2 * was higher in rat lungs exposed to iron-oxide particles, compared with control lungs and that this difference in R 2 * reflected the presence of deposited particles in lung tissue. We then applied this technique to the study of the effect of gravity on the deposition of fine particles and to the study of aerosol deposition in emphysematous lungs. We have shown that, for similar breathing patterns and aerosol exposure, particle deposition was higher and more heterogeneously distributed in emphysematous lungs when compared to healthy lungs. These MRI studies have generated rich experimental datasets that can also be used to validate in-silico models of aerosol transport in the lung. More recently, we have investigated the effect of particle size on the distribution of deposited particles in the murine lung and have showed significant heterogeneities in deposition both at the lobar and near-acini level.

Experimental approaches include:

  • Aerosol exposure during mechanical ventilation
  • Animal plethysmography
  • MRI

Relevant publications

  • Oakes, J.M., M. Scadeng, E.C. Breen, A.L. Marsden and C. Darquenne. Rat airway morphometry measured from in-situ MRI-based geometric models. J. Appl. Physiol., 112:1921-1931, 2012 (doi:10.1152/japplphysiol.00018.2012, PMC3379152).
  • Oakes, J.M., M. Scadeng, E.C. Breen, G.K. Prisk and C. Darquenne. Regional distribution of aerosol deposition in rat lungs using magnetic resonance imaging. Ann. Biomed. Eng., 41:967-978, 2013. (DOI: 10.1007/s10439-013-0745-2, PMC3625510)
  • Oakes, J.M., E. Breen, M. Scadeng, G.S. Tchantchou and C. Darquenne. MRI-based measurements of aerosol deposition in the lung of healthy and elastase-treated rats. J. Appl. Physiol., 116:1561-1568, 2014 (DOI: 10.1152/japplphysiol.01165.2013, PMC4064380).
  • Gu, W. and C. Darquenne. Heterogeneity in lobar and near-acini deposition of inhaled aerosol in the mouse lung. J. Aerosol Sci., 151:105642, 2021 (doi: 10.1016/j.jaerosci.2020.105642, PMC7480823).

A full list of publications can be found on Chantal Darquenne's UCSD profile page.