Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral chest radiograph demonstrates clear lungs . No pleural effusion or pneumothorax . Heart size , mediastinal contour , and hila are unremarkable . Interval resolution of left perihilar opacity . Pacer wires are unchanged in positioning with lead tips in right ventricle and right atrium . Limited assessment of the upper abdomen is within normal limits .
    OUTPUT:
    
Normal chest radiograph . Resolution of left perihilar pneumonia .