Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable chest radiograph is obtained . Lungs appear grossly clear bilaterally without definite signs of pneumonia or CHF . Heart size is top normal , though this may be due to technique . Mediastinal contour is normal with faint atherosclerotic calcification along the aortic knob . Bony structures are intact . No large effusion or pneumothorax is seen .
    OUTPUT:
    
No signs of pneumonia .