Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable AP radiograph demonstrates no focal opacity convincing for pneumonia . Bilateral hila appear prominent , possibly reflective of pulmonary vessels though adenopathy can not be excluded . Heart is normal in size . Mediastinal contour is otherwise unremarkable . There is no large pleural effusion or pneumothorax . Visualized osseous structures are without an acute abnormality . No air under the right hemidiaphragm is seen .
    OUTPUT:
    
Prominent bilateral hilar contours may reflect prominent pulmonary arteries though adenopathy can not be excluded . Comparison with prior films would be helpful . Lungs are clear .