Figure 2b. Acute chest syndrome in a 49-year-old man who presented with progressive shortness of breath and fever after an intravenous cocaine binge. (a) Chest radiograph shows abnormal bilateral parenchymal opacities, which are more confluent in the right midlung zone. (b) High-resolution computed tomographic (CT) scan demonstrates diffuse bilateral reticular opacities with superimposed thickening of inter- and intralobular interstitium ("crazy paving pattern").