Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiograph is compared to radiograph performed ___ . The overall appearance of the chest is unchanged though lung volumes are slightly lower . Mild emphysematous changes are noted with flattened diaphragms . Cardiomediastinal and hilar contours are stable . Bibasilar atelectasis is present on the frontal projection but does not persist on the lateral where there is better inspiratory effort . There is no evidence of pleural effusion , pneumothorax , or pulmonary edema .
    OUTPUT:
    
No acute intrathoracic abnormality . Emphysematous changes .