Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear unchanged . The right upper paratracheal stripe is widened , but the appearance is stable over time and in comparison to the CT torso . The appearance is probably due to tortuosity of the great vessels and prominent mediastinal fat . Patchy left basilar opacity is not specific but could be seen with minor atelectasis . There is no pleural effusion or pneumothorax . Mild degenerative changes are noted along the thoracic spine . No free air is seen .
    OUTPUT:
    
Vague opacity in the left lower lung , nonspecific and probably due to atelectasis . Other etiologies including pneumonia are not completely excluded , however .