-Transient Tachypnoea of the Newborn (TTN, also called Retained Fetal Lung Fluid or "Wet Lung") is a diagnosis of exclusion.

-Typical radiologic features are ill-defined but include:

1-Increased central vascular markings ("star-burst" appearance)

2-Hyperaeration

3-Evidence of interstitial and pleural fluid

4-Prominent interlobar fissures

5-Cardiomegaly

-Because the symptoms and radiological features are non-specific, infection should be considered in the differential diagnosis. Typically, respiratory symptoms resolve within the first 24-hours of life, but occasionally can persist longer.

http://www.adhb.govt.nz/newborn/TeachingResources/Radiology/LungParenchyma.htm