Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are present . The cardiac , mediastinal and hilar contours are unchanged , with the heart size appearing top normal . The aorta is slightly tortuous with aortic knob calcifications again noted . Bibasilar patchy ill - defined opacities are present , and could reflect areas of atelectasis or aspiration . No pleural effusion or pneumothorax is visualized . No acute osseous abnormalities are seen .
    OUTPUT:
    
Patchy ill - defined opacities in the lung bases in the setting of low lung volumes . Findings could reflect aspiration or atelectasis .