Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There are new subtle airspace opacities in the left lower lung along the left heart border and at the right cardiophrenic angle . The lungs are otherwise clear . Mediastinal contours are stable . No pleural effusion or pneumothorax .
    OUTPUT:
    
Subtle airspace opacities in the lower lungs bilaterally could represent pneumonia in the appropriate clinical context .