Fig. 21-2. The relations of the trachea, bronchi, esophagus, and aorta to one another. In the right anterior oblique view, the right lobar and segmental bronchi are omitted because they are not clearly visible in radiographs of this view. For similar reasons, the left lobar and segmental bronchi are omitted from the left anterior oblique view. The horizontal line indicates the level of the carina. Click for high resolution image.