Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac silhouette size is likely mildly enlarged . The aortic knob is slightly calcified , and the mediastinal contours are relatively unchanged . There is mild pulmonary vascular engorgement . Ill - defined opacities are noted in the lung bases , which may reflect atelectasis , though infection or aspiration can not be excluded . No pleural effusion or pneumothorax is present . There are no acute osseous abnormalities .
    OUTPUT:
    
Low lung volumes with ill - defined opacities in the lung bases which may reflect atelectasis , infection or aspiration .