Atherosclerosis of the aorta
Definition
Atherosclerosis is characterised by irregularly distributed lipid deposits in the intima of large and medium-sized arteries; such deposits are associated with fibrosis and calcification.
 
Radiographic Appearance
 On plain films of he chest and abdomen the calcifications in the plaques in the walls of the arteries are often visible, frequently they are seen secondary to studies of the abdomen and lumbar spine.
 
Pathology
 When atherosclerosis begins, white blood cells that are called monocytes will migrate from the blood stream and into the wall of the artery. They are then transformed into cells that will accumulate fatty materials and in time form a patchy thickening called plaque. This plaque builds in the inner lining of the artery filling each area with a soft cheese like substance. These areas of thickening are called atheroma and they may be scattered through out the large and medium arteries but in most cases they are found where the arteries branch off. It is believed that this is because these areas have constant turbulence which injures the arterial walls. Most of the thickening is created by fatty materials such as cholesterol, connective tissue cells and smooth muscles cells. Since arteries that are affected with atherosclerosis tend to loose their elasticity, the antheromas will continue to grow narrowing the arteries even more. When this occurs the atheromas will collect calcium deposits becoming brittle with time. This may lead to a rupture of the atheroma where the fatty contents are spilled out to trigger the formation of a blood clot or what is known as thrombus. This may further narrow the artery or create an embolism.

In most cases atherosclerosis does not produce symptoms until an artery is severely narrowed or a sudden obstruction occurs. Then the symptoms will depend on where the disease has developed. In this part of the body pain or cramps may occur during exercise. When this occurs it is because the area of the body that is affected is not receiving enough blood and oxygen. Examples of this would be chest pain during exercise or leg cramps while walking. In most cases these symptoms tend to develope slowly as the artery narrows but if an obstruction occurs such as a blood clot lodged in an artery, the symptoms may appear suddenly.

Other risk factors with atherosclerosis might include a relative who has developed the disease at a young age. In most cases men are at a greater risk than women even though after menopause a womans risk will increase. Inherited diseases such as homocystinuria which causes an extensive formation of atheroma at a young age are at a higher risk of developing this disease. Even though this disease affects many different arteries in the body, it does not affect the coronary arteries. On the other hand, inherited diseases such as familial hypercholesterolemia which creates very high levels of blood cholesterol will cause atheromas to occur mainly in the coronary arteries.
 
Treatment:

Medication. Medications that lower cholesterol or control high blood pressure may be prescribed. Medication also is available that has been shown to significantly increase pain-free walking distance and total walking distance in people with intermittent claudication. Other medications that help prevent blood clots or the build-up of plaque in the arteries are available, as well.

Angioplasty. In this procedure, an interventional radiologist inserts a very small balloon attached to a thin tube (catheter) into a blood vessel through a small nick in the skin. The catheter is threaded under X-ray guidance to the site of the blocked artery. The balloon is inflated to open the artery. In some cases, a tiny metal cylinder, or stent, is left behind in the artery to keep it open.

Thrombolytic therapy. This treatment is used by an interventional radiologist if the blockage in the artery is caused by a blood clot. Thrombolytic drugs - sometimes called clot-bursting drugs - dissolve the clot and restore blood flow. Usually, the drugs are administered through a catheter directly into the clot. These drugs are frequently combined with another treatment, such as angioplasty.

Bypass grafts. In this procedure, a vein graft from another part of the body or a graft made from artificial material is used to create a detour around the blocked artery. Bypass grafts typically require surgery, but other ways of placing the grafts without major surgery are now being developed.

Thrombectomy. This procedure is used only when symptoms of PVD develop suddenly as the result of a blood clot. In the technique, a balloon catheter is inserted into the affected artery beyond the clot. The balloon is inflated and pulled back, bringing the clot with it. Thrombectomy usually is performed as an open surgical procedure.

 
Image 1 atherosclerosis in the lumber region

Image 2 Athersclerosis and a leaking aneurysm CT