Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single frontal view of the chest was obtained portably . Low lung volumes results in bronchovascular crowding . Increased opacity at the right lung base since ___ likely represents a pleural effusion and atelectasis but supervening infection can not be excluded . The right upper lung zone and the left lung are clear . The cardiac silhouette is unchanged . Mediastinal silhouette and hilar contours are normal .
    OUTPUT:
    
Right lower lung opacity likely represents pleural effusion and atelectasis , but supervening infection can not be excluded .