Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest are provided . There is left basilar linear opacity which is stable and corresponds with atelectasis on prior imaging . No definite signs of pneumonia or CHF . No effusion or pneumothorax . Cardiomediastinal silhouette appears within normal limits . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Mild left basal atelectasis . Otherwise , unremarkable .