The third period of time (8th – 20th day) was marked by even less amount of changes revealed according to both methods.

During the third period of time we registered IPA pathognomonic symptom – air crescent sign, represented by moderately chromogenic cavity with roundish solid content. The content was separated from a wall by thin crescent achromogenic layer of air, resembling crescent moon. The sign was revealed in 9% by Bioplasm nls software
-study and in 3.6% by roentgenography.

In one patients we diagnosed a pneumothorax.