Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low as on the study of ___ . Mild atelectasis at the left base is improved . Mild right basilar atelectasis is unchanged . There is no evidence of new focal airspace opacity . There is no large pleural effusion or pneumothorax . Heart size is normal .
    OUTPUT:
    
Mild bibasilar atelectasis slightly improved at the left base . Low lung volumes . No evidence of pneumonia .