Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single AP radiograph of the chest demonstrates clear lungs with mild bibasilar atelectasis . Cardiac , hilar , and mediastinal contours are within normal limits . No pleural effusion or pneumothorax . No subdiaphragmatic free air is identified . Osseous structures are grossly normal . Mesh from hernia repair is noted in the left upper quadrant .
    OUTPUT:
    
No evidence of pneumoperitoneum . No acute cardiopulmonary abnormality .