Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable frontal view of the chest . The lung volumes are exceedingly low , resulting in crowding of the bronchovascular structures and bilateral atelectasis . There is no definite pleural effusion . No pneumothorax . Cardiac silhouette and mediastinum are likely unchanged , accounting for low lung volumes .
    OUTPUT:
    
Low lung volumes , without a definite acute cardiopulmonary process .