Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are markedly low which limit the evaluation . There is no focal consolidation , large effusion , or pneumothorax . Heart size is top normal . Mediastinal contour is unremarkable . There is mild prominence of pulmonary vasculature . Bony structures are intact . No free air below the right hemidiaphragm .
    OUTPUT:
    
Limited study without sefinite signs of pneumonia or overt CHF . Please refer to subsequent CTA chest for additional details .