Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Prior sternotomy was done for AVR . Significant mediastinal and cardiac contour enlargement is unchanged and by reviewing the CT , it is mostly due to lipomatosis . Multiple calcified pleural plaques are from previous asbestos exposure .
    OUTPUT:
    
There is no significant change since the previous exam . 1 . Mediastinal and cardiac contour enlargement is mostly due to mediastinal lipomatosis . 2 . Previous asbestos exposure .