Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear unchanged . There is new vague , fairly streaky opacity projecting over the left upper lung which is difficult to visualize on the lateral view , but new . There is no pleural effusion or pneumothorax . No fracture is identified .
    OUTPUT:
    
Vague new opacity in the left upper lung ; possibilities include pneumonia , atelectasis or interval development of mild scarring .