Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Compared to yesterday 's exam , there is increased opacity in the left lower lung which could represent atelectasis versus pneumonia . The right lung is clear . Cardiomediastinal silhouette is stable . Imaged osseous structures are intact . No free air below the right hemidiaphragm is seen .
    OUTPUT:
    
Left basal opacity is new from yesterday 's exam and may represent atelectasis versus pneumonia .