Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiographs were obtained . The cardiomediastinal silhouette is unchanged . Postsurgical changes are seen at the right base . Known right upper lobe opacity continues to improve . Left lung is clear . No pleural effusions . No pneumothorax .
    OUTPUT:
    
Right upper lobe opacification , first seen on ___ , continues to improve over time . Given the time course , this likely represents a slowly resolving infection .