Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is top normal . The mediastinal and hilar contours are within normal limits . Pulmonary vasculature is not engorged . Patchy and linear opacities are seen within the left lung base and right mid lung field , likely areas of atelectasis though infection in the left lung base is not completely excluded . Small left pleural effusion is present . No pneumothorax is identified . There are no acute osseous abnormalities .
    OUTPUT:
    
Patchy and linear opacities in the left lung base and right mid lung field which may reflect areas of atelectasis though infection in the left lung base can not be completely excluded in the correct clinical setting . Trace left pleural effusion .