Fig. 1

Chest x-ray. a Anterior-posterior (AP) film obtained on admission demonstrating normal heart, lung, mediastinum, and bony thorax shadows. b Posterior-anterior (PA) film obtained on day 4 of admission to investigate the patient’s acute respiratory failure. The film demonstrates extensive new bilateral acinar opacification in a mainly perihilar distribution throughout all lobes of both lungs in a fairly symmetrical distribution. Normal cardiac contours and pulmonary vascularity are seen