This X ray shows an aneurysm of the descending aorta.compare Descendenzaneurysma_pict3aAneurysms occur in different parts of the aorta, e.g. aorta ascendens, aortic arch, aorta descendens, aorta abdominalis. There are true and false aneurysms.Clinically there is a simplified classification:thoracic aortic aneurysm (variety aortic dissection)abdominal aortic aneurysm (mostly infrarenal)
