Figure 4e. (a-c) Arterial dissection after minor thoracic trauma in a 23-year-old patient with type IV Ehlers-Danlos syndrome. (a) Axial CT image of the origin of the left subclavian artery shows an intimomedial flap, which divides the artery into true (T) and false (F) lumina. (b) Axial CT image shows a crescent-shaped intramural hematoma (arrowheads) surrounding the true lumen. (c) Sagittal volume rendered image shows a dissection of the proximal descending aorta (type B dissection) (arrow). The dissection extends into the origin of the left subclavian artery. (d, e) Arterial rupture after minor thoracic trauma in a 19-year-old patient with type IV Ehlers-Danlos syndrome. (d) Coronal thin-slab MIP image shows a ruptured aneurysm of the left subclavian artery (arrow), which caused left-sided hemothorax. There is also a nonruptured, partially calcified aneurysm of the right subclavian artery. This aneurysm was asymptomatic and was probably chronic. (e) Oblique coronal volume rendered image from the arterial phase includes only the arterial vessels and thus shows the aneurysms more clearly.