Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Interval resolution of patchy right upper lobe opacity , which may have been due to contusion or aspiration . Lungs are otherwise clear . Right hemidiaphragm is mildly elevated . There is no pleural effusion or pneumothorax . Known L1 fracture is seen to better detail on recent CT .
    OUTPUT:
    
Resolution of right upper lobe opacity may have been due to contusion or aspiration .