Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild cardiomegaly with unfolding of the thoracic aorta is unchanged . Mild . Scattered calcifications of the aortic knob . Mild central pulmonary vascular prominence without interstitial edema . Subtle bibasilar opacities , greater on the right , appear less prominent than on prior examination , likely representing atelectasis .
    OUTPUT:
    
Likely bibasilar atelectasis , though early or developing pneumonia can not be fully excluded given the appropriate clinical circumstance .