Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are relatively low lung volumes and bibasilar atelectasis . Left base opacity is seen with differential diagnosis of the pneumonia or atelectasis . This opacity appears new since ___ . No large pleural effusion is seen . There is no pneumothorax . Cardiac and mediastinal silhouettes are stable . There is gaseous distention of the stomach and of bowel underlying both diaphragms . Degenerative changes at the glenohumeral joints and high - riding right humeral head are seen .
    OUTPUT:
    
Low lung volumes . Left base opacity seen laterally ; differential diagnosis includes infection or atelectasis , new since the prior study from ___ .