Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is interval increased hazy opacity in the left lung base , with loss of the " clear " spine sign in the lateral view . There is no pneumothorax or pleural effusion . The cardiomediastinal silhouette remains mildly enlarged but unchanged . There is no evidence of pulmonary edema .
    OUTPUT:
    
Interval increased hazy opacity in the left lung base , could represent either atelectasis or infectious process .