Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP radiograph of the chest demonstrates relatively low lung volumes compared to the prior study with persistent interstitial prominence and minimal pulmonary vascular engorgement without overt pulmonary edema . No pleural effusion or pneumothorax is present . Hazy opacity in the right lung base likely represents atelectasis , however underlying infection can not be completely excluded . The cardiac silhouette is stable .
    OUTPUT:
    
Hazy opacity in the right lung base likely represents atelectasis in the presence of low lung volumes , however , underlying infection can not be completely excluded .