Figure 18b.  Ulcerlike projection after intramural hematoma. (a) Enhanced CT scan obtained at admission shows an intramural hematoma of the descending aorta (arrow). Ten months later, the patient developed a type B open dissection. (b) CT scan shows a double-lumen dissection of the descending aorta with dilatation and mural thrombosis of the false lumen (arrow). (c) Sagittal MPR image shows the open dissection with a distal intimal tear and retrograde dissection (arrow).