Expansion
T1 inlet, T4/5 sternal angle, T8 caval, T9 xiphisternum, T10 oesophagus, T12 aorta
Expansion
| Level | Landmark |
|---|---|
| T1 | Thoracic inlet; superior border of the manubrium at T2/T3 |
| T2 | Suprasternal notch, approximately |
| T4/T5 | Sternal angle: carina, aortic arch limits, azygos arch, mediastinal division |
| T8 | Caval opening: inferior vena cava and right phrenic nerve |
| T9 | Xiphisternal joint |
| T10 | Oesophageal hiatus: oesophagus and vagal trunks |
| T12 | Aortic hiatus: aorta, azygos, thoracic duct |
The pattern to notice is that the three diaphragmatic openings sit at even numbers going down, 8, 10, 12, while the sternal angle at T4/T5 is the single most useful reference in the thorax.
Adding the neighbouring landmarks completes the picture: the cricoid cartilage and the start of the trachea and oesophagus at C6, and the aortic bifurcation at L4.