Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were obtained . Lung volumes are somewhat low . There is a retrocardiac streaky opacity which could represent a left lower lobe pneumonia . Crowding of bronchovasculature likely accounts for the subtle opacity adjacent to the right heart border . No large pleural effusion or pneumothorax is seen . The heart and mediastinal contours appear stable and normal . Bony structures are intact .
    OUTPUT:
    
Retrocardiac opacity which could represent left lower lobe pneumonia .