Dragos M. Vasilescu MS, Presenter: Nothing to Disclose

Joseph Reinhardt PhD, Abstract Co-Author: Stockholder, VIDA Diagnostics

Matthias Ochs MD, Abstract Co-Author: Nothing to Disclose

Ewald R. Weibel MD, DSc, Abstract Co-Author: Nothing to Disclose

Eric A. Hoffman PhD, Abstract Co-Author: Shareholder, VIDA Diagnostics Medical Advisory Board, Siemens AG

In recent years various mouse models have been developed for observing lung disease and treatment progression. The main purpose of this study is to define ways to phenotype the normal murine lung to better quantify the changes that occur during various pathologic processes. For assessing the morphometry of the murine lung with respect to macroscopic (airway) and microscopic (alveolar) anatomy, scanning at various levels of magnifications is necessary.

A novel microCT scanner (XRadia, MicroXCT, Conconrd, California) allows for localized imaging of the intact mouse lung at any pre-selected location. We are using this capability to non-destructively assess the whole murine lung via design based stereology. After performing an in-vivo scan at 20cmH2O water column pressure, the murine lungs are fixed through perfusion fixation at the same trans-pulmonary pressure. The in-vivo scan images were reconstructed with a voxel size of 28µm. After excision the lungs were scanned again at a low resolution followed by localized high resolution scans. The ex-vivo scans were reconstructed with a voxel size of 21µm and respectively with a 2µm voxel size. This imaging cascade permits measurements using manual and automatic algorithms for characterizing the whole lung, from macroscopic to microscopic anatomy.

Measurements that were performed on the low-resolution scans include whole lung volumes and airway morphometry. Using the sub-sample images we calculated the following parameters: acinar volume, branch pattern, and path and branch lengths within an acinus. Applying the stereology approach to the CT-sampled lung, the following parameters could be determined: volume of alveoli and alveolar ducts; alveolar surface; septal volume; septal thickness; alveolar number and size.

In conclusion we demonstrate that non-destructive multi-resolution microCT imaging combined with unbiased stereologic sampling allows for a multi-scale assessment of the normal murine lung.

An atlas derived from such measures will provide important information for the assessment of pathologic processes in the murine lung model.

Vasilescu, D, Reinhardt, J, Ochs, M, Weibel, E, Hoffman, E, Morphometry of the Murine Lung via Multi-Resolution Micro X-ray CT.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8016296.html