Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates increased opacification of the left upper lung field consistent with pneumonia . There is a small area of increased opacification of the left base , which likely represents atelectasis . There is a stable appearing right upper lung nodule . The cardiomediastinal contours are unchanged . The heart is top normal in size . There is no pneumothorax or pleural effusion . The right - sided internal jugular central venous line ends at the cavoatrial junction .
    OUTPUT:
    
Increased opacification of the left upper lobe is most suggestive of pneumonia .