This is a non specific descriptive sentence based on a subjective assessment or impression. Often it does not correspond to any real abnormality. I myself do not use this in my reports. I prefer to give a precise description of the abnormality, which could be one of the following examples:

- Bronchial wall thickening seen in chronic asthma or in chronic bronchitis also known as chronic obstructive airways disease(in smokers).

-Dilatation of the arteries in heart failure, or rarely in shunts of the heart.

- Linear infiltrates in edema from heart failure.

- Illdefined infiltrates in bronchopneumonia(infection).

Etc....

As you can deduce from the above, any of these findings should be correlated with the clinical symptoms of the patient to see if they fit.