Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single AP portable view of the chest is provided . Bibasilar atelectasis , particularly at the right lower lobe , is improved since ___ but still present . Otherwise , the lungs are clear . Cardiomediastinal silhouette is grossly unremarkable . Mediastinal contours appear normal . No pleural effusion , pneumothorax or opacities concerning for infectious process are present .
    OUTPUT:
    
Moderate bibasilar atelectasis , improved since ___ .