Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates low lung volumes with resultant bronchovascular crowding . Retrocardiac opacity is increased over the interval and may represent atelectasis or pneumonia in the appropriate clinical setting . Moderate to severe cardiomegaly is stable . The endotracheal tube ends 4 .4 cm from the carina . The intra-aortic balloon pump tip ends 1 .8 cm from the aortic arch and is in acceptable position . The nasogastric tube tip ends in the distal esophagus , with the last side port at the level of the carina . No pneumothorax . The pacer lead is no longer present on this view .
    OUTPUT:
    
1 . Increased retrocardiac opacity may represent atelectasis or pneumonia in the appropriate clinical setting . 2 . Intra-aortic balloon pump tip ends 1 .8 cm from the aortic arch , and is in acceptable position . 3 . Nasogastric tube tip ends in the distal esophagus , with the last side port at the level of the carina .