Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are low lung volumes . The heart size remains moderately enlarged . The aorta is tortuous but stable . There is mild pulmonary vascular congestion with perihilar haziness . More focal opacities in the lung bases may reflect atelectasis , though infection in these regions can not be completely excluded . Small left pleural effusion appears similar compared to the prior study . No pneumothorax is identified . Mild loss of height anteriorly of an upper lumbar vertebral body is unchanged .
    OUTPUT:
    
Mild pulmonary vascular congestion and small left pleural effusion . More focal opacities in the lung bases may reflect atelectasis , though infection in these regions can not be completely excluded .