What is the limit between the superior and inferior mediastinum?
Boundaries: the superior mediastinum is bounded superiorly by the thoracic inlet and inferiorly by a horizontal line through the sternal angle.
What passes through superior mediastinum?
- Organs: thymus, trachea, esophagus.
- Arteries: aortic arch, brachiocephalic trunk, left common carotid artery, left subclavian artery.
- Veins and lymphatics: superior vena cava, brachiocephalic veins, the arch of the azygos, thoracic duct.
What is superior mediastinal widening?
Mediastinal widening on CXR is defined as width of more than 8 cm on posteroanterior view. It can be commonly due to lymph node enlargement, vascular causes, neoplasia, and rarely due to gastrointestinal causes such as achalasia or hernia.
What is the superior boundary of the superior mediastinum?
Superior mediastinum. The superior mediastinum is a space bounded anteriorly by the manubrium of the sternum, and posteriorly by the bodies of T1-T4 vertebrae. Its superior border is an oblique plane extending from the jugular notch of the manubrium to the superior border of T1 vertebra.
What causes mediastinal shift?
Mediastinal shift may be caused by volume expansion on one side of the thorax, volume loss on one side of the thorax, mediastinal masses and vertebral or chest wall abnormalities. An emergent condition classically presenting with mediastinal shift is tension pneumothorax.
What passes through superior thoracic aperture?
The right and left subclavian arteries and veins pass through the superior thoracic aperture. These vessels may be compromised by pathologic conditions of the lower cervical or upper thoracic viscera.
Is mediastinal widening serious?
The most significant life-threatening concern associated with a wide mediastinum is an acute aortic rupture or aortic dissection. Additional imaging must be obtained to investigate these diagnoses.
What are the causes of mediastinal widening?
Widening of the mediastinum is most often due to technical factors such as patient positioning or the projection used. Rotation, incomplete inspiration, or an AP view, may all exaggerate the width of the mediastinum, as well as heart size.
What occurs when a patient experiences a mediastinal shift?
mediastinal shift a shifting or moving of the tissues and organs that comprise the mediastinum (heart, great vessels, trachea, and esophagus) to one side of the chest cavity. The condition occurs when a severe injury to the chest causes the entrapment of air in the pleural space (tension pneumothorax).
How do you test for mediastinal shift?
Assess and compare the space between the trachea and sternomastoid on either side. Keep the tips of your index and ring fingers over the medial end of the clavicles. Then, with the middle finger, assess the space between the trachea and sternomastoid. Caution: Make sure that your nails are trimmed.
What passes through superior and inferior thoracic aperture?
Structures passing through the thoracic outlet between the thorax and abdomen include the inferior vena cava and esophagus, both of which pass through the diaphragm, and the abdominal aorta and thoracic duct which pass through the diaphragm, through the aortic hiatus.
Why is the superior thoracic aperture called thoracic outlet?
The superior thoracic aperture, also known as the thoracic inlet or outlet, connects the root of the neck with the thorax.
What causes a widening of superior mediastinum?
Is a widened mediastinum serious?
What are the causes of shift of mediastinum?
How do you assess mediastinal shift?
Assess and compare the space between the trachea and sternomastoid on either side. Keep the tips of your index and ring fingers over the medial end of the clavicles. Then, with the middle finger, assess the space between the trachea and sternomastoid.