Name : Morteza
Affiliation : Radiology Department,Hasheminejad Hospital,TUMS
Academic Degree: Assistant Professor of Radiology
Resident : Hussein Soleiman Tabar
Gender : Male
Age : 50
50 year-old male presented to emergency room with chest pain
Imaging Procedures and Findings
There is a huge aneurysm of descending thoracic aorta with calcified walls. Also evident are pericardial effusion and left pleural effusion.
Thoracic aortic aneurysm is a focal or diffuse dilatation of the thoracic aorta usually caused by degenerative diseases such as atherosclerosis and cystic medial necrosis. Infrequently, the etiology is congenital (Marfans syndrome), inflammatory (relapsing polychondritis cardiovascular manifestation), infectious or traumatic. The normal diameter of the thoracic aorta is less than 4.0 cm for the ascending, and less than 3.0 cm for the descending portions. A diameter exceeding 5 cm is usually considered an aneurysm. A diameter of the aorta greater than 1.5 times the normal diameter also constitutes an aneurysm. Aneurysms may be fusiform (concentric radial dilatation) or saccular (eccentric radial dilatation). Atherosclerosis and cystic medial necrosis usually produce fusiform aneurysms while infections cause saccular aneurysms (mycotic aneurysm). True aneurysms have all three layers of the wall while false aneurysms consist only of media. Infection and trauma cause false aneurysms. The etiologies of thoracic aortic aneurysms include: atherosclerosis, cystic medial necrosis (Marfans syndrome and Ehlers Danlos syndrome), aortoannular ectasia, syphilis cardiovascular, aortitis, relapsing polychondritis cardiovascular manifestation, Takayasus arteritis, and Behcets disease. Aneurysms may be caused by eccentric jet flow across a stenotic or nonstenotic bicuspid aortic valve or coarctation of the aorta. Plain radiography demonstrates generalized or focal bulging of the aortic contour. Aneurysm of the ascending aorta causes enlargement of the right superior mediastinum and obliteration of the retrosternal air space. The aneurysmal contour not uncommonly is calcified. Definition of the diameter and extent of aneurysm can be provided by aortography, CT, MRI and magnetic resonance angiography. Currently, the preferred imaging modalities for initial diagnosis and monitoring of the diameter are MRI, MR angiography and spiral or electron beam CT. Sequential tomographic imaging has shown that thoracic aortic aneurysms enlarge faster than abdominal aortic aneurysms (4.2 vs. 2.8 mm/year). A maximum diameter exceeding 6.0 cm has a likelihood of rupture five times greater than one less than 6.0 cm, so this dimension is considered an indication for early surgery.
Aneurysm of Descending Portion of Thoracic Aorta