Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright and lateral views of the chest provided . The cardiomediastinal silhouette is unchanged in this patient with known tortuosity of the thoracic aorta accounting for prominence of the mediastinum . Lung volumes are low though lungs appear clear . No pleural effusion or pneumothorax . Bony structures appear intact .
    OUTPUT:
    
No acute intrathoracic process . Mediastinal prominence due to unfolded thoracic aorta .