Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild enlargement of the cardiac silhouette is unchanged . Mediastinal contours are unremarkable . The pulmonary vasculature is not engorged . Patchy opacities in the lung bases , particularly in the left lung base , are worse compared to the previous study . There may be a trace right pleural effusion . No pneumothorax is present . No acute osseous abnormality is seen .
    OUTPUT:
    
Increased patchy bibasilar airspace opacities , particularly on the left , concerning for worsening infection .