Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As compared to prior chest radiograph from ___ , there has been interval widening of the mediastinum , likely due to normal vascular filling . There is no evidence of tracheal narrowing . Thyroidectomy clips appear in a slightly changed position from prior examination . The cardiac silhouette is within normal limits . Lungs are clear . There are no pleural effusions or pneumothorax .
    OUTPUT:
    
Interval widening of mediastinum likely due to normal vascular filling . No evidence of airway abnormalities .