Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable chest radiograph was provided . The lungs appear clear bilaterally . There is mild bibasilar atelectasis . Cardiomediastinal silhouette appears normal , allowing for technique . Bony structures are intact .
    OUTPUT:
    
No acute intrathoracic process . Please refer to subsequent CTA chest for further details .