Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is top normal . The mediastinal and hilar contours are within normal limits . Pulmonary vascularity is not engorged . Focal opacity is noted within the right lung base , which likely represents a summation of shadows , and no correlate can be seen on the lateral view . There is no pleural effusion or pneumothorax . No acute osseous abnormality is seen .
    OUTPUT:
    
No definite evidence for pneumonia . Focal opacity within the right lung base likely represents a summation of shadows .