Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views of the chest were obtained . Lung volumes are low . There is mild left and right lung base atelectasis . No definite signs of pneumonia or CHF . No pleural effusion or pneumothorax is seen . Cardiomediastinal silhouette appears grossly stable . Atherosclerotic calcifications along the aortic knob noted . Bony structures appear intact .
    OUTPUT:
    
Mild bibasilar atelectasis . No definite signs of pneumonia or CHF .