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Computed tomography angiography (also called CT angiography or CTA) is a computed tomography technique used to visualize arterial and venous vessels throughout the body. This ranges from arteries serving the brain to those bringing blood to the lungs, kidneys, arms and legs. ==Medical uses== CTA can be used to examine blood vessels in many key areas of the body, including the brain, kidneys, pelvis, and the lungs. Under some circumstances the coronary arteries may be examined by CTA, but CTA has not replaced invasive catheter coronary angiography. The procedure is able to detect narrowing of blood vessels in time for corrective therapy to be done. This method displays the anatomical detail of blood vessels more precisely than magnetic resonance imaging (MRI) or ultrasound. Today, many patients can undergo CTA in place of a conventional catheter angiogram. CTA is a useful way of screening for arterial disease because it is safer and much less time-consuming than catheter angiography and is a cost-effective procedure. There is also less discomfort because contrast material is injected into an arm vein rather than into a large artery in the groin. CTA is commonly used for the following purposes: *Examine the pulmonary arteries in the lungs to rule out pulmonary embolism, a serious but treatable condition. This is called a CTPA. *Visualize blood flow in the renal arteries (those supplying the kidneys) in patients with high blood pressure and those suspected of having kidney disorders. Narrowing (stenosis) of a renal artery is a cause of high blood pressure (hypertension) in some patients and can be corrected. A special computerized method of viewing the images makes renal CT angiography a very accurate examination. Also done in prospective kidney donors. *Identify aneurysms in the aorta or in other major blood vessels. Aneurysms are diseased areas of a weakened blood vessel wall that bulges out—like a bulge in a tire. Aneurysms are life-threatening because they can rupture. *Identify dissection in the aorta or its major branches. Dissection means that the layers of the artery wall peel away from each other—like the layers of an onion. Dissection can cause pain and can be life-threatening. *Identify a small aneurysm or arteriovenous malformation inside the brain that can be life-threatening. *Detect atherosclerotic disease that has narrowed the arteries to the legs. *Exclude coronary artery disease, especially in low to intermediate risk patients. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Computed tomography angiography」の詳細全文を読む スポンサード リンク
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