Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Hypodense widening of the upper mediastinum is unchanged over multiple radiographs , reflecting mediastinal lipomatosis as seen on prior CT examinations . The heart is mildly enlarged . There is no pulmonary edema , focal consolidation , pneumothorax , or pleural effusion . Mild bibasilar atelectasis is present .
    OUTPUT:
    
No acute intrathoracic process .