Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . Mediastinal contours are unremarkable . There is mild pulmonary vascular congestion . Opacification in the left lung base is concerning for pneumonia . There is a small left pleural effusion . No pneumothorax is identified . No acute osseous abnormalities seen .
    OUTPUT:
    
Left basilar pneumonia and small left pleural effusion . Mild pulmonary vascular congestion .