Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral radiographs of the chest demonstrate clear lungs . The cardiac and mediastinal contours are normal . Calcified nodule in the left lower lobe is stable since prior CT . No focal areas of opacity are seen . No pleural abnormality is detected .
    OUTPUT:
    
No evidence of active or latent tuberculosis infection . No evidence of pneumonia .