Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single portable semi-erect chest radiograph was obtained . Low lung volumes exaggerate the heart size and interstitial markings . The lungs are clear . There is no focal consolidation , effusion , or pneumothorax . The heart size is top normal . Mediastinal contours are normal . Cholecystectomy clips are visible in the right upper quadrant . There is no displaced rib fracture .
    OUTPUT:
    
Top normal heart size .