Patients with respiratory distress syndrome may have relatively normal-appearing lungs on day 0, especially if they are on ventilatory support (and especially if there is a cuffed tube).

This case highlights the development of subtotal pulmonary interstitial emphysema and highlights that with modulation of ventilatory pressures, differential resolution may occur resulting in atypical patterns of residual disease.

In preterm babies with RDS, new focal areas of increased lucency with linear areas of opacification should trigger a thought about PIE. It doesn't need to be symmetrical or total-lung.