You can score them after stained with Masson's trichrome (Collagen). You may score them based on thickness of the collagen deposition or severity of the fibrosis (semi quantification like 1-4 scale).

Good Luck.

Arul.

Thank you  Arul!

Do you know of any published work that has this on their methods? 

Hi Carolina, you can score lung fibrosis based on pixel counts of your stained slides:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3252890/

http://www.biomedcentral.com/1471-2407/13/179

http://www.pnas.org/content/103/48/18278.full

http://scholar.google.com/scholar?q=%22lung+fibrosis%22+%22pixel+count%22&btnG=&hl=en&as_sdt=1%2C21

Thank you Steingrimur!

I'll check on the references you kindly posted here.

Hi Carolina, Please check this reference.

Great!

Thank you Arul.

Caution...Masson's is NOT specific for collagen, it also detects BM components. If you want to quantitate collagen specifically, the only histo stain specific for it is picrosirius red, which also can be digitally quantitated under polarized light. Sorry Arul...Carolina, email if you need citations

Check the article

"Biotechniques. 2008 Apr;44(4):507-11, 514-7. doi: 10.2144/000112729.

Standardized quantification of pulmonary fibrosis in histological samples.

Hübner RH1, Gitter W, El Mokhtari NE, Mathiak M, Both M, Bolte H, Freitag-Wolf S, Bewig B"

They use a Modified Scale of the Ashcroft Scale

Thanks Yehuda!

You can use picrosirius red, which stains collagen red, or you can use Gordon and Sweet's reticular fibre stain, which stains collagen types I and III fibres black.  We quantify the collagen based on colour pixels using the image analysis software ImagePro Plus, or you can use a program like Image J.