Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are noted with crowding of the bronchovascular markings . Left basilar opacity obscuring the left costophrenic angle . Cardiomediastinal silhouette is within normal limits for technique . Median sternotomy wires and mediastinal clips are noted .
    OUTPUT:
    
Low lung volumes . Left basilar opacity may represent any combination of effusion , atelectasis or consolidation