Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bilateral increased interstitial markings in the lower lungs are demonstrated but may reflect underlying emphysema . Retrocardiac opacity with silhouetting of the left hemidiaphragm border could reflect edema , atelectasis or consolidation / pneumonia . A nodular opacity projecting over the left lung apex likely represents a chronic rib deformity . No large pleural effusion . No pneumothorax . Perihilar asymmetric opacities in the left lung could also represent foci of infection .
    OUTPUT:
    
1 . Retrocardiac opacity and asymmetric left perihilar opacities could reflect edema though pneumonia can not be excluded in the appropriate clinical situation . 2 . Emphysema .