Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The upper lungs are well - expanded . There is a small area of volume loss in the retrocardiac region but no definite infiltrate . No focal consolidation , edema , effusion , or pneumothorax . The cardiac silhouette remains enlarged , similar to prior exams . The mediastinum is not widened . Aortic knob calcifications are mild .
    OUTPUT:
    
No focal pneumonia . Persistent enlarged cardiac silhouette , unchanged .