Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to the prior chest radiograph and ___ , the lung volumes have decreased which causes crowding of the bronchovascular structures . Right lower lobe in the retrocardiac region opacity most likely atelectasis , however , superimposed infection can not be excluded . The cardiac and mediastinal contours are stable . There is no pleural effusion pneumothorax .
    OUTPUT:
    
Bilateral lower lobe opacities most likely represent atelectasis , however , infection can not be excluded in the appropriate clinical setting . Repeat radiographs with a deeper inspiration could be obtained if clinically indicated .