Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest demonstrate low lung volumes , which accentuate bronchovascular markings . There is no focal consolidation , pleural effusion , or pneumothorax . Hilar and mediastinal silhouettes are unremarkable . Heart size is normal . There is a tubular opacity in the left mid lung at the ___ posterior rib level . Partially imaged upper abdomen is unremarkable .
    OUTPUT:
    
Low lung volumes . Tubular opacity in the left mid lung very likely represents superimposition of normal vessels and less likely a vascular malformation of mucous plugging . Repeat radiographs with shallow oblique views may be helpful for further assessment .