Chest X-ray

Widened mediastinum (caused by mediastinal haematoma)

Widened or double lumen to aortic knuckle

Irregular aortic contour

Discrepancy in diameter of ascending and descending thoracic aorta (lateral film)

Displacement of calcified intima

Small left pleural effusion (15–20% Type A or B dissections) resulting from inflammation

Large left pleural effusion as a sign of rupture

Transthoracic echocardiography

Dissection flap

Dilated aorta

Aortic regurgitation

Pericardial effusion

Transoesophageal echocardiography

As for transthoracic echocardiography but better definition of dissection flap with imaging of true and false lumen and

entry tears

Intramural haematoma:

• Aortic wall >5 mm thick.
• Echolucencies caused by blood in the aortic wall.
• Fascial planes in the aortic wall which ‘shear’ during systole.

Penetrating ulcer:

• Usually descending thoracic aorta
• Crater-like outpouching through intima
• Extensive atheroma