Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heterogeneous opacification at the left lung base may represent a developing infection . Otherwise , the lungs are clear . Left upper extremity PICC line terminates in the lower SVC . Cardiomediastinal silhouette is normal . Again seen is a mild rightward curvature of thoracic spine . No pleural effusion or pneumothorax .
    OUTPUT:
    
Subtle heterogeneous opacification of the left lung base may represent a developing infection , possibly atypical pneumonia .