Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral chest radiograph demonstrates no focal opacity convincing for pneumonia . Blunting of the right costophrenic angle is similar in appearance to prior examinations . Cardiac silhouette is stable in appearance as are mediastinal and hilar contours . Aortic arch calcification is noted . There is no pneumothorax .
    OUTPUT:
    
No acute intrathoracic abnormality .