Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest . No prior . There is left basilar opacity which partially obscures the left lateral heart border , potentially due to atelectasis although a developing infiltrate is also possible . Elsewhere , lungs are clear . There is no pneumothorax or effusion . Cardiomediastinal silhouette is within normal limits . Osseous and soft tissue structures are unremarkable .
    OUTPUT:
    
Lingular opacity partially silhouetting the heart border , potentially due to atelectasis however developing infiltrate is not excluded and clinical correlation is suggested .