Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart is upper limits of normal in size . Mediastinal and hilar contours are normal . Lung volumes are relatively low . Focal opacity at left lung base with adjacent elevation of left hemidiaphragm favors atelectasis . Small pleural effusions are present bilaterally .
    OUTPUT:
    
1 . Focal left lower lobe opacity is likely due to localized atelectasis adjacent to an elevated hemidiaphragm . 2 . No evidence of congestive heart failure .