Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low bilateral lung volumes . There has been interval placement of an intra-aortic balloon pump for which the exact location is difficult to ascertain as the aortic arch is not clearly visualized . It however likely projects 5 .7 cm from the presumed top of the arch . Retrocardiac opacity likely reflects atelectasis . Mild pulmonary vascular congestion . The size the cardiomediastinal silhouette is enlarged .
    OUTPUT:
    
Limited examination determine the exact location of the intra-aortic balloon pump . The top of the aortic arch is difficult to ascertain on this radiograph but the IABP is roughly 5 .7 cm from the presumed top of the arch . A repeat radiograph could be helpful .