Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The ET tube is in the proximal right mainstem bronchus . Right central venous catheter terminates in the mid SVC . Intra-aortic balloon pump is just below the level of the carina and could be advanced approximately 2 .5 cm . Since the prior study there has been significant improved aeration of the left lung . There is persistent left retrocardiac opacity and small left effusion . The right lung is clear . No pneumothorax .
    OUTPUT:
    
The ET tube is in the proximal right mainstem bronchus . Right central venous catheter terminates in the mid SVC . Intra-aortic balloon pump is just below the level of the carina and could be advanced approximately 2 .5 cm . Since the prior study there has been significant improved aeration of the left lung . There is persistent left retrocardiac opacity and small left effusion . The right lung is clear . No pneumothorax .