Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable upright view of the chest demonstrates ill - defined opacity in the lateral right lung base , slightly more conspicuous since ___ . Similar opacities seen in the left lung base , has progressed since prior . Prominence of interstitial markings persists . Hilar and mediastinal silhouettes are unremarkable . The descending aorta is mildly tortuous . Heart size is normal . There is no pneumothorax . Healing remote left - sided rib fracture is noted .
    OUTPUT:
    
Ill - defined opacities in bilateral lung bases , more conspicuous since ___ exam , could be atypical infection .