Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded and clear . The cardiomediastinal silhouette and hilar contours are normal . No pleural effusion or pneumothorax is present .
    OUTPUT:
    
No acute intrathoracic process . Specifically , no mediastinal air is noted . Please note , however , that if esophageal perforation remains a clinical concern , then an esophagram is the study of choice , whereas if an aortic dissection is the clinical concern then a CT may be obtained .