Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP semi-upright portable chest radiograph is obtained . There are lower lung vague opacity , which is concerning for pneumonia , less likely atelectasis . Calcified pleural plaque is clearly visualized at the left lung base . No definite pleural effusion or pneumothorax is seen . The heart and mediastinal contour appears normal . The imaged osseous structures are intact .
    OUTPUT:
    
Lower lung opacities concerning for pneumonia , less likely atelectasis .