ICM-II: CHEST, case 2

TYPE-this is a frontal chest image, no air-fluid level is seen but this does not determine for sure whether it is upright or not, scapulae are slightly rotated but it looks like the arms are overhead, based on the position of the humeri. In fact, this is an image called a 'topogram' or 'scout' image that is done before a CT scan. It is a low quality digital radiograph done on the CT table to figure out where to start and stop the scanning. So the patient is supine with arms overhead.

What do you think is outlined in blue? Based on the width and height of the lungs, this patient has not taken a very deep breath and their lungs do not look entirely clear.