Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are normal . Lungs are clear . Previously described left lower lobe 6 mm tubular density on CT has no correlate on the prior chest radiograph . The Pulmonary vasculature is normal . No pleural effusion or pneumothorax is present . No acute osseous abnormalities present .
    OUTPUT:
    
No acute cardiopulmonary abnormality . Please note that the previously described 6 mm tubular opacity in the left lower lobe on prior CT is not visualized on this exam . As recommended on the prior CT in ___ , the patient is due for a follow up 6 - month chest CT .