Fundamental Radiological Findings: Endotracheal Tube


This page is dedicated to covering the radiological appearance of an endotracheal tube. 


An endotracheal tube is a wide bored breathing tube that is used to assist ventilation. It typically is about 1cm in width, and has a radiopaque marker stripe on the side. The tip often is diagonally shaped. It is a piece of medical equipment that can be visualized on medical imaging.

The stripe on the side of the endotracheal tube (pointed out by the black arrow) is radiopaque and will appear on a X-ray image to help visualize the tube (source)

Often the proper placement of the endotracheal tube can be assessed on a chest X-ray:

Location of the tip: With the patient’s head in the neutral position (i.e. bottom of mandible is at the level of C5/C6) the tip of the tube should be about 3 to 5 cm from the carina. This is roughly half the distance between the medial ends of the clavicles and the carina.  Neck flexion may cause a 2 cm decent of the tip which is why it should be a further distance from the carina.

Inflation of the cuff: the inflated cuff of the tube should NOT distend the lumen of the trachea.


Sometimes the improper placement of endotracheal tubes can be appreciated on a chest X-ray. Here is what to look out for:

Placement of the tip in the bronchus: most commonly these tips are malpositioned into he main or right lower lobe bronchi. This can lead to atelectasis of the non-aerated lung and pneumothorax can also be caused by damage to pulmonary structures.

Placement of the tip high in the neck: this can lead to damage of the vocal cords. The tube should be at least 3 cm distal to the vocal cords.

Intubation of the esophagus: if the tube was inserted in the esophagus the stomach will be hyper inflated.


Page Updated: 01.08.2016