What is hyperaeration of the lungs?

I had posted a few months back about abnormal chest xray reportsin my 4-year old child.  The cardiothymic area was questioned about being enlarged and was read as normal this time.  But, in the impression, as well as the body of the dictation, it is read as marked hyperaeration.  What could this mean?  I have heard the term but am not familiar with its definition.  Can you help me?

[National Jewish]

Hyper aeration usually means that the lungs are expanded and have more air than one would expect.  Thus, the term "hyper" rather than "normal" aeration is used.  If your child was crying or simply taking in a large breath at the time of the chest x-ray, this can show up.  It is most commonly seen in people during an asthma attack, adults with emphysema and other lung conditions.

[xrayu2]

I did her xray myself and she had a normal breath hold, was not upset at all.  It was a six month f/u because there had been question of an enalrged mediastinal area.  The cardiothymic area was normal but the radiologist read it as persistent hyperaeration(when comparing to all the previous films). That particular doctor has not been  on my clinic rotation and the pediatrician had the receptionist call and say  she probably had bronchitis(but she had just had her well child visit with him).  Thank you for your answer!  I am still searching for the why at this point.

[jes778]

A related discussion, hyperaeration of lungs was started.

[bag156]

A related discussion, lung aeraton was started.

[janice_21]

A related discussion, pulmonary hyperaeration was started.