CT has a sensitivity of nearly 100% for detecting AAA, and it has certain advantages over ultrasonography for defining aortic size, rostral-caudal extent, involvement of visceral arteries, and extension into the suprarenal aorta (see the image below). CT permits visualization of the retroperitoneum, is not limited by obesity or bowel gas, detects leakage, and allows concomitant evaluation of the kidneys. Spiral (helical) CT allows three-dimensional (3D) imaging of abdominal contents, facilitating detection of branch vessel and adjacent organ involvement.
CT demonstrates abdominal aortic aneurysm (AAA). Aneurysm was noted during workup for back pain, and CT was ordered after AAA was identified on radiography. No evidence of rupture is seen.
Preoperative CT is helpful for more clearly defining the anatomy of the aneurysm and other intra-abdominal pathologic conditions. Nonenhanced CT is used to size aneurysms. [16] As important as sizing the aneurysm is determining the anatomic relations that are relevant to surgical repair. These include the location of the renal arteries, the length of the aortic neck, the condition of the iliac arteries, and the presence of anatomic variants such as a retroaortic left renal vein or a horseshoe kidney.
Enhanced spiral CT of the abdomen and pelvis with multiplanar reconstruction and CT angiography (CTA) is the modality of choice for preoperative evaluation for open and endovascular repair (see the image below).
-
Radiograph shows calcification of abdominal aorta. Left wall is clearly depicted and appears aneurysmal; however, right wall overlies spine.
-
On radiography, lateral view clearly shows calcification of both walls of abdominal aortic aneurysm, allowing diagnosis to be made with certainty.
-
CT demonstrates abdominal aortic aneurysm (AAA). Aneurysm was noted during workup for back pain, and CT was ordered after AAA was identified on radiography. No evidence of rupture is seen.
-
Arteriography demonstrates infrarenal abdominal aortic aneurysm. This arteriogram was obtained in preparation for endovascular repair of aneurysm.
-
Lateral arteriogram demonstrates infrarenal abdominal aortic aneurysm. Demonstration of superior mesenteric artery, inferior mesenteric artery, and celiac artery on lateral arteriogram is important for complete evaluation of extent of aneurysm.
-
Arteriogram after successful endovascular repair of abdominal aortic aneurysm.
-
Ultrasonogram from patient with abdominal aortic aneurysm (AAA). This aneurysm was best visualized on transverse or axial image. Patient underwent conventional AAA repair.
-
MRI of 77-year-old man with leg pain believed to be secondary to degenerative disk disease. During evaluation, abdominal aortic aneurysm was discovered.
-
Age is risk factor for development of aneurysm.
-
Inflammation, thinning of media, and marked loss of elastin.
-
Pulsatile abdominal mass.
-
Aneurysm with retroperitoneal fibrosis and adhesion of duodenum.
-
Aortic endoprosthesis (Cook aortic and aortobi-iliac endograft).
-
Endoaneurysmorrhaphy
-
Endovascular grafts.
-
Atheroemboli from small abdominal aortic aneurysms produce livedo reticularis of feet (ie, blue toe syndrome).
-
Enhanced spiral CT scans with multiplanar reconstruction and CT angiogram.
-
Angiography is used to diagnose renal area. In this instance, endoleak represented continued pressurization of sac.
