Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are relatively low with bibasilar atelectasis . Superiorly , lungs are clear . There is no overt edema nor effusion . The cardiomediastinal silhouette is stable . Prosthetic aortic valve and left chest wall dual lead pacing device are unchanged . There is a new dual lumen right - sided central venous catheter with distal tip in the right atrium . Bilateral shoulder arthroplasties are noted as well as lumbar fixation hardware . .
    OUTPUT:
    
Low lung volumes without definite acute cardiopulmonary process .