I read with interest the article written by Jones et al published in CHEST (July 2016). I really enjoyed the last part that considers limitations. However, I think that there are other points to be discussed.
In my opinion, the inclusion criteria consisting of patients from birth to 21 years could determine a selection bias. Community-acquired pneumonia in children has a range of patterns more related to patient age than to causative agent. In infants, air trapping may be the only radiologic sign. Edema and mucus in these airways can determine a peripheral atelectasis. Small plugs in peripheral airways generate lesser or greater accumulated small blotches of atelectasis. Up to 8 years of age, round pneumonias, which are often central and not detectable by ultrasonography, are possible. Major consolidations (exudate or other product of disease that replaces alveolar air) become common when developed channels and pores allow the spread of the infection.
Ultrasonography is superior in identifying small subpleural echogenic areas. These focal atelectases are relatively usual in healthy lungs on CT imaging. They are common in patients with asthma and bronchiolitis (see earlier discussion).
B-lines are nonspecific regarding a causative production of signals due to the modification of the plane immediately below the pleura (volume and arrangement of the alveoli, fluid, and so on). They are common in normal infants (Fig 1).
Finally, imaging is insensitive for the identification of the cause of pneumonia.