Aortic Dissection: Diagnosis and Follow-up with Helical CT
Carmen Sebastià, MD1,
Esther Pallisa, MD1,
Sergi Quiroga, MD1,
Agustí Alvarez-Castells, MD1,
Rosa Dominguez, MD1 and
Arturo Evangelista, MD2
1 Departments of Radiology (C.S., E.P., S.Q., A.A., R.D.)
2 Cardiology (A.E.), Hospital General Universitari Vall d'Hebron, Paseo Vall d'Hebron 119–129, Barcelona 08035, Spain.
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Figure 1a. Stanford type A aortic dissection. (a, b) Enhanced CT scans show an intimal flap (arrow) in the ascending aorta (a) and brachiocephalic trunk (b). (c) Oblique sagittal two-dimensional reconstruction image shows the intimal flap in the ascending aorta (bottom arrow) with extension to the brachiocephalic trunk (top arrow).
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Figure 1b. Stanford type A aortic dissection. (a, b) Enhanced CT scans show an intimal flap (arrow) in the ascending aorta (a) and brachiocephalic trunk (b). (c) Oblique sagittal two-dimensional reconstruction image shows the intimal flap in the ascending aorta (bottom arrow) with extension to the brachiocephalic trunk (top arrow).
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Figure 1c. Stanford type A aortic dissection. (a, b) Enhanced CT scans show an intimal flap (arrow) in the ascending aorta (a) and brachiocephalic trunk (b). (c) Oblique sagittal two-dimensional reconstruction image shows the intimal flap in the ascending aorta (bottom arrow) with extension to the brachiocephalic trunk (top arrow).
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Figure 2a. Stanford type B aortic dissection. (a) Enhanced CT scan shows an intimal flap in the descending aorta (arrow). There is flow within both lumina. (b) Oblique sagittal MPR image shows the aortic dissection (bottom arrow). The origin of the dissection is distal to the left subclavian artery (top arrow).
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Figure 2b. Stanford type B aortic dissection. (a) Enhanced CT scan shows an intimal flap in the descending aorta (arrow). There is flow within both lumina. (b) Oblique sagittal MPR image shows the aortic dissection (bottom arrow). The origin of the dissection is distal to the left subclavian artery (top arrow).
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Figure 3a. Aortic motion artifact. (a) Enhanced CT scan shows an aorta with an artifactual rim of low attenuation (arrow). (b) Oblique sagittal MPR image shows a serrated appearance of the left anterior wall of the ascending aorta (arrow), particularly at the aortic root.
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Figure 3b. Aortic motion artifact. (a) Enhanced CT scan shows an aorta with an artifactual rim of low attenuation (arrow). (b) Oblique sagittal MPR image shows a serrated appearance of the left anterior wall of the ascending aorta (arrow), particularly at the aortic root.
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Figure 4. Figures 4, 5. (4) Mural thrombus. CT scan shows an atheromatous thrombus with an irregular internal border in the thoracic descending aorta (arrow) and motion artifact in the ascending aorta. A thrombosed aortic dissection usually demonstrates a smooth internal border. (5) Focal periaortic soft-tissue mass. (a) CT scan shows idiopathic periaortic fibrosis (arrows). (b) CT scan shows periaortic lymphoma as a focal rounded mass at the aortic border (arrows). These periaortic masses have an irregular external border, whereas intramural hematoma appears as smooth, crescentic thickening of the aortic wall (see Fig 6).
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Figure 5a. Figures 4, 5. (4)Mural thrombus. CT scan shows an atheromatous thrombus with an irregular internal border in the thoracic descending aorta (arrow) and motion artifact in the ascending aorta. A thrombosed aortic dissection usually demonstrates a smooth internal border. (5) Focal periaortic soft-tissue mass. (a) CT scan shows idiopathic periaortic fibrosis (arrows). (b) CT scan shows periaortic lymphoma as a focal rounded mass at the aortic border (arrows). These periaortic masses have an irregular external border, whereas intramural hematoma appears as smooth, crescentic thickening of the aortic wall (see Fig 6).
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Figure 5b. Figures 4, 5. (4)Mural thrombus. CT scan shows an atheromatous thrombus with an irregular internal border in the thoracic descending aorta (arrow) and motion artifact in the ascending aorta. A thrombosed aortic dissection usually demonstrates a smooth internal border. (5) Focal periaortic soft-tissue mass. (a) CT scan shows idiopathic periaortic fibrosis (arrows). (b) CT scan shows periaortic lymphoma as a focal rounded mass at the aortic border (arrows). These periaortic masses have an irregular external border, whereas intramural hematoma appears as smooth, crescentic thickening of the aortic wall (see Fig 6).
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Figure 6a. Intramural hematoma of the descending aorta. (a) Unenhanced CT scan shows a crescentic area of high attenuation (left arrow) with medial displacement of intimal calcifications (right arrow). (b) Enhanced CT scan shows the crescentic area as hypoattenuating relative to the aortic lumen. Arrow = intimal calcification. (c) Oblique sagittal MPR image shows the intramural hematoma (bottom arrow). Top arrow = intimal calcification.
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Figure 6b. Intramural hematoma of the descending aorta. (a) Unenhanced CT scan shows a crescentic area of high attenuation (left arrow) with medial displacement of intimal calcifications (right arrow). (b) Enhanced CT scan shows the crescentic area as hypoattenuating relative to the aortic lumen. Arrow = intimal calcification. (c) Oblique sagittal MPR image shows the intramural hematoma (bottom arrow). Top arrow = intimal calcification.
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Figure 6c. Intramural hematoma of the descending aorta. (a) Unenhanced CT scan shows a crescentic area of high attenuation (left arrow) with medial displacement of intimal calcifications (right arrow). (b) Enhanced CT scan shows the crescentic area as hypoattenuating relative to the aortic lumen. Arrow = intimal calcification. (c) Oblique sagittal MPR image shows the intramural hematoma (bottom arrow). Top arrow = intimal calcification.
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Figure 7a. Intramural hematoma of the ascending aorta. (a) Unenhanced CT scan shows a crescentic area of high attenuation along the walls of the ascending and descending aorta (arrows). (b) Enhanced CT scan does not show enhancement of the crescentic areas (arrows).
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Figure 7b. Intramural hematoma of the ascending aorta. (a) Unenhanced CT scan shows a crescentic area of high attenuation along the walls of the ascending and descending aorta (arrows). (b) Enhanced CT scan does not show enhancement of the crescentic areas (arrows).
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Figure 8a. Penetrating atherosclerotic ulcer. (a–c) CT angiograms (shown from superior [a] to inferior [c]) show a penetrating ulcer of the right lateral wall of the descending aorta (arrow in a and b) and distal intramural hematoma (arrowhead in c). (d) Sagittal MPR image shows the ulcer (arrow) and the intramural hematoma (arrowhead).
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Figure 8b. Penetrating atherosclerotic ulcer. (a–c) CT angiograms (shown from superior [a] to inferior [c]) show a penetrating ulcer of the right lateral wall of the descending aorta (arrow in a and b) and distal intramural hematoma (arrowhead in c). (d) Sagittal MPR image shows the ulcer (arrow) and the intramural hematoma (arrowhead).
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Figure 8c. Penetrating atherosclerotic ulcer. (a–c) CT angiograms (shown from superior [a] to inferior [c]) show a penetrating ulcer of the right lateral wall of the descending aorta (arrow in a and b) and distal intramural hematoma (arrowhead in c). (d) Sagittal MPR image shows the ulcer (arrow) and the intramural hematoma (arrowhead).
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Figure 8d. Penetrating atherosclerotic ulcer. (a–c) CT angiograms (shown from superior [a] to inferior [c]) show a penetrating ulcer of the right lateral wall of the descending aorta (arrow in a and b) and distal intramural hematoma (arrowhead in c). (d) Sagittal MPR image shows the ulcer (arrow) and the intramural hematoma (arrowhead).
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Figure 9a. Ruptured type B dissection. (a) Unenhanced CT scan shows hyperattenuating periaortic mediastinal hematoma (arrow) and hyperattenuating pleural effusion (arrowheads). (b) Enhanced CT scan shows irregularity of the aortic wall with an ulcerlike appearance caused by extravasation of vascular contrast material (arrow).
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Figure 9b. Ruptured type B dissection. (a) Unenhanced CT scan shows hyperattenuating periaortic mediastinal hematoma (arrow) and hyperattenuating pleural effusion (arrowheads). (b) Enhanced CT scan shows irregularity of the aortic wall with an ulcerlike appearance caused by extravasation of vascular contrast material (arrow).
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Figure 10. Figures 10, 11. (10) Dissection of the entire intima. Enhanced CT scan shows dissection of the entire intima in the thoracic descending aorta (arrow) (11) Filiform true lumen. Enhanced CT scan shows a filiform true lumen in the thoracic descending aorta (arrow).
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Figure 11. Figures 10, 11. (10) Dissection of the entire intima. Enhanced CT scan shows dissection of the entire intima in the thoracic descending aorta (arrow). (11) Filiform true lumen. Enhanced CT scan shows a filiform true lumen in the thoracic descending aorta (arrow).
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Figure 12. Figures 12, 13. (12) Calcified false lumen. Venous-phase enhanced CT scan shows an abdominal aortic dissection with mural calcification of the false lumen (arrows). (13) Three-channel aorta. CT angiogram shows two false lumina (F) in the thoracic descending aorta. The intimal flap demonstrates the Mercedes-Benz sign.
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Figure 13. Figures 12, 13. (12) Calcified false lumen. Venous-phase enhanced CT scan shows an abdominal aortic dissection with mural calcification of the false lumen (arrows). (13) Three-channel aorta. CT angiogram shows two false lumina (F) in the thoracic descending aorta. The intimal flap demonstrates the Mercedes-Benz sign.
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Figure 14a. Aortic coarctation and dissection. (a) Oblique sagittal MPR image shows focal narrowing of the thoracic descending aorta (long arrow) and an intimal flap in the ascending aorta (short arrow). (b) SSD image shows a dilated ascending aorta and aortic narrowing immediately distal to the left subclavian artery (arrow). Dissection is not seen because an SSD image shows only the aortic surface.
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Figure 14b. Aortic coarctation and dissection. (a) Oblique sagittal MPR image shows focal narrowing of the thoracic descending aorta (long arrow) and an intimal flap in the ascending aorta (short arrow). (b) SSD image shows a dilated ascending aorta and aortic narrowing immediately distal to the left subclavian artery (arrow). Dissection is not seen because an SSD image shows only the aortic surface.
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Figure 15a. Figures 15, 16. (15) Pseudoaneurysm after surgery for type A dissection in a 28-year-old man with Marfan syndrome. The surgery involved replacement of the aortic valve and placement of a Dacron graft in the aortic root. (a) Enhanced CT scan shows a pseudoaneurysm of the aortic root (arrows). Note the aortic motion artifacts (arrowheads). (b) SSD image shows the pseudoaneurysm of the aortic root (arrow). (16) Aneurysm after surgery for type A dissection 9 years earlier. The surgery involved replacement of the aortic valve and angioplasty of the intimal tear with a patch graft. (a) Enhanced CT scan shows an aneurysm of the ascending aorta with a persistent intimal flap (arrow). (b) SSD image shows the aneurysm of the ascending aorta with extension to the aortic arch.
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Figure 15b. Figures 15, 16. (15) Pseudoaneurysm after surgery for type A dissection in a 28-year-old man with Marfan syndrome. The surgery involved replacement of the aortic valve and placement of a Dacron graft in the aortic root. (a) Enhanced CT scan shows a pseudoaneurysm of the aortic root (arrows). Note the aortic motion artifacts (arrowheads). (b) SSD image shows the pseudoaneurysm of the aortic root (arrow). (16) Aneurysm after surgery for type A dissection 9 years earlier. The surgery involved replacement of the aortic valve and angioplasty of the intimal tear with a patch graft. (a) Enhanced CT scan shows an aneurysm of the ascending aorta with a persistent intimal flap (arrow). (b) SSD image shows the aneurysm of the ascending aorta with extension to the aortic arch.
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Figure 16a. Figures 15, 16. (15) Pseudoaneurysm after surgery for type A dissection in a 28-year-old man with Marfan syndrome. The surgery involved replacement of the aortic valve and placement of a Dacron graft in the aortic root. (a) Enhanced CT scan shows a pseudoaneurysm of the aortic root (arrows). Note the aortic motion artifacts (arrowheads). (b) SSD image shows the pseudoaneurysm of the aortic root (arrow). (16) Aneurysm after surgery for type A dissection 9 years earlier. The surgery involved replacement of the aortic valve and angioplasty of the intimal tear with a patch graft. (a) Enhanced CT scan shows an aneurysm of the ascending aorta with a persistent intimal flap (arrow). (b) SSD image shows the aneurysm of the ascending aorta with extension to the aortic arch.
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Figure 16b. Figures 15, 16. (15) Pseudoaneurysm after surgery for type A dissection in a 28-year-old man with Marfan syndrome. The surgery involved replacement of the aortic valve and placement of a Dacron graft in the aortic root. (a) Enhanced CT scan shows a pseudoaneurysm of the aortic root (arrows). Note the aortic motion artifacts (arrowheads). (b) SSD image shows the pseudoaneurysm of the aortic root (arrow). (16) Aneurysm after surgery for type A dissection 9 years earlier. The surgery involved replacement of the aortic valve and angioplasty of the intimal tear with a patch graft. (a) Enhanced CT scan shows an aneurysm of the ascending aorta with a persistent intimal flap (arrow). (b) SSD image shows the aneurysm of the ascending aorta with extension to the aortic arch.
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Figure 17a. Healing of intramural hematoma. (a, b) Unenhanced (a) and enhanced (b) CT scans obtained at the level of the aortic arch show a crescentic area (top arrow) and displacement of calcifications (bottom arrow), findings consistent with a fresh intramural hematoma. (c) Follow-up CT scan obtained 7 months later shows that the intramural hematoma has been absorbed.
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Figure 17b. Healing of intramural hematoma. (a, b) Unenhanced (a) and enhanced (b) CT scans obtained at the level of the aortic arch show a crescentic area (top arrow) and displacement of calcifications (bottom arrow), findings consistent with a fresh intramural hematoma. (c) Follow-up CT scan obtained 7 months later shows that the intramural hematoma has been absorbed.
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Figure 17c. Healing of intramural hematoma. (a, b) Unenhanced (a) and enhanced (b) CT scans obtained at the level of the aortic arch show a crescentic area (top arrow) and displacement of calcifications (bottom arrow), findings consistent with a fresh intramural hematoma. (c) Follow-up CT scan obtained 7 months later shows that the intramural hematoma has been absorbed.
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Figure 18a. 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).
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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).
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Figure 18c. 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).
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Figure 19a. Aneurysm of the false lumen in a patient who had type B AAD 10 years earlier. (a) Enhanced CT scan obtained 10 years earlier shows an intimal flap (arrow) in a descending aorta of normal diameter. (b) Helical CT scan shows dilatation and mural thrombosis of the false lumen (arrow). (c) Oblique sagittal MPR image shows irregular mural thrombosis of the false lumen (F), which compresses the true lumen.
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Figure 19b. Aneurysm of the false lumen in a patient who had type B AAD 10 years earlier. (a) Enhanced CT scan obtained 10 years earlier shows an intimal flap (arrow) in a descending aorta of normal diameter. (b) Helical CT scan shows dilatation and mural thrombosis of the false lumen (arrow). (c) Oblique sagittal MPR image shows irregular mural thrombosis of the false lumen (F), which compresses the true lumen.
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Figure 19c. Aneurysm of the false lumen in a patient who had type B AAD 10 years earlier. (a) Enhanced CT scan obtained 10 years earlier shows an intimal flap (arrow) in a descending aorta of normal diameter. (b) Helical CT scan shows dilatation and mural thrombosis of the false lumen (arrow). (c) Oblique sagittal MPR image shows irregular mural thrombosis of the false lumen (F), which compresses the true lumen.
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Figure 20a. Aneurysm of the true lumen in a patient with polycystic kidney disease. (a) Enhanced CT scan shows an abdominal aortic dissection (arrow). (b) Enhanced CT scan obtained 11 years later shows an aneurysm of the true lumen (arrows). (c) Oblique sagittal MPR image shows the anterior abdominal aneurysm of the true lumen (large arrow) and slow flow in the false lumen (F) (small arrows).
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Figure 20b. Aneurysm of the true lumen in a patient with polycystic kidney disease. (a) Enhanced CT scan shows an abdominal aortic dissection (arrow). (b) Enhanced CT scan obtained 11 years later shows an aneurysm of the true lumen (arrows). (c) Oblique sagittal MPR image shows the anterior abdominal aneurysm of the true lumen (large arrow) and slow flow in the false lumen (F) (small arrows).
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Figure 20c. Aneurysm of the true lumen in a patient with polycystic kidney disease. (a) Enhanced CT scan shows an abdominal aortic dissection (arrow). (b) Enhanced CT scan obtained 11 years later shows an aneurysm of the true lumen (arrows). (c) Oblique sagittal MPR image shows the anterior abdominal aneurysm of the true lumen (large arrow) and slow flow in the false lumen (F) (small arrows).
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Figure 21a. Static obstruction of the mesenteric artery. (a) Enhanced CT scan shows that the intimal flap enters the superior mesenteric artery. The true lumen (black arrow) is narrowed by a circumferential thrombosed false lumen that extends to the superior mesenteric artery (white arrows). (b) Sagittal MPR image shows the intimal flap (black arrow) and thrombosed false lumen in the superior mesenteric artery (white arrows).
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Figure 21b. Static obstruction of the mesenteric artery. (a) Enhanced CT scan shows that the intimal flap enters the superior mesenteric artery. The true lumen (black arrow) is narrowed by a circumferential thrombosed false lumen that extends to the superior mesenteric artery (white arrows). (b) Sagittal MPR image shows the intimal flap (black arrow) and thrombosed false lumen in the superior mesenteric artery (white arrows).
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Figure 22a. Dynamic obstruction of the renal artery. (a) Enhanced CT scan shows dynamic obstruction of the right renal artery (black arrow) and infarction of the right kidney (white arrows). (b) Coronal MPR image obtained at the level of the renal arteries shows a collapsed true lumen (black arrow) at the right renal ostium (white arrow).
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Figure 22b. Dynamic obstruction of the renal artery. (a) Enhanced CT scan shows dynamic obstruction of the right renal artery (black arrow) and infarction of the right kidney (white arrows). (b) Coronal MPR image obtained at the level of the renal arteries shows a collapsed true lumen (black arrow) at the right renal ostium (white arrow).
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Figure 23a. Thrombosis of the iliac artery. (a) Enhanced CT scan shows an abdominal aortic dissection with obliteration of the true lumen (arrow). (b) CT scan shows thrombosis of the right common iliac artery (arrow). (c) Maximum-intensity projection image of the abdominal aorta shows obstruction of the right common iliac artery.
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Figure 23b. Thrombosis of the iliac artery. (a) Enhanced CT scan shows an abdominal aortic dissection with obliteration of the true lumen (arrow). (b) CT scan shows thrombosis of the right common iliac artery (arrow). (c) Maximum-intensity projection image of the abdominal aorta shows obstruction of the right common iliac artery.
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Figure 23c. Thrombosis of the iliac artery. (a) Enhanced CT scan shows an abdominal aortic dissection with obliteration of the true lumen (arrow). (b) CT scan shows thrombosis of the right common iliac artery (arrow). (c) Maximum-intensity projection image of the abdominal aorta shows obstruction of the right common iliac artery.
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Copyright © 1999 by the Radiological Society of North America.
