Fig. 5. Type I: patent false lumen with both entry and re-entry; Type II: ‘cul-de-sac’-shaped false lumen with no re-entry (subdivided into IIa, patent true lumen; IIb, severe stenosis of the true lumen; and IIc, occlusion of the true lumen); Type III: thrombosed false lumen with an ULP (subdivided into IIIa, patent true lumen; IIIb, severe stenosis of the true lumen; and IIIc, occlusion of the true lumen); Type IV: completely thrombosed false lumen with no ULP (subdivided into IVa, patent true lumen; IVb, severe stenosis of the true lumen; and IVc, occlusion of the true lumen); Type V: dissecting aneurysm. ULP: ulcer-like projection.