1.2 Mediastinum
1.2.1 Superior mediastinum sternal angle
trachea, esophagus, thymus gland, great vessels {Superior vena cava(SVC),
Inferior vena cava (IVC), Aorta}
1.2.2 Anteior mediastinum sternum, pericardium
1.2.3 Middle mediasatinum pericardium heart
1.2.4 Posterior mediastinum pericardium, vertebra esophagus,
descending (thoracic ) aorta