Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal contours are stable . A rounded density posterior to the carina on the lateral projection is new since the prior study . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
New rounded opacity posterior to the carina of unclear etiology . Nopnemergent chest CT recommended for further evaluation . Dr . ___ ___ these results with Dr . ___ at 5 :37 PM on ___ via telephone .