Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal and hilar contours are remarkable for tortuosity of the thoracic aorta . The pulmonary vasculature is normal . Lungs are clear except for new peribronchiolar opacities in the retrocardiac portion of the left lower lobe . No pleural effusion or pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
New peribronchial left lower lobe opacities are concerning for developing pneumonia or an acute aspiration event .