Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear . Mediastinal and cardiac contours are unremarkable except for unchanged deviation of the trachea towards the left , which could be due to a thyroid nodule .
    OUTPUT:
    
1 . There is no evidence of pericardial effusion on this exam , which is not sensitive for a small amount of fluid . The cardiac contour is normal . 2 . Possible right thyroid enlargement to be investigated with dedicated sonogram if needed .