Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The inspiratory lung volumes are slightly decreased . Mild opacification at the left costophrenic angle may represent atelectasis or underpenetration . No definite consolidation concerning for pneumonia is seen . No significant pleural effusion or pneumothorax is present . The cardiac silhouette is top normal in size . The cardiomediastinal and hilar contours are within normal limits and unchanged from the prior study . Calcification at the aortic knob is noted . No displaced rib fractures are detected .
    OUTPUT:
    
Limited examination with no acute cardiopulmonary process .