computed tomography angiography

WordNet

1. X-ray machine in which a computer builds a detailed image of a particular plane through an object from multiple X-ray measurements
2. roentgenographic examination of blood vessels after injection of a radiopaque contrast medium; produces an angiogram

PrepTutorEJDIC

1. …'を'計算する,見積もる / 計算する,算定する

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2018/01/12 01:27:19」(JST)

wiki en

[Wiki en表示]

Computed tomography angiography
Medical diagnostics
Sagittal thin slice of a computed tomography angiography abdominal aortic aneurysm (AAA) (arrows)
OPS-301 code	3-228

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.

Coronary CT angiography

Main article: Coronary CT angiography

Image of contrast enhanced dual-source coronary CT-angiograph.

Coronary CT angiography (CTA) is the use of CT angiography to assess the coronary arteries of the heart. The subject receives an intravenous injection of radiocontrast and then the heart is scanned using a high speed CT scanner, allowing radiologists to assess the extent of occlusion in the coronary arteries, usually in order to diagnose coronary artery disease. 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.

Other uses

CTA is commonly used for the following purposes:

• CT pulmonary angiogram (CTPA) to examine the pulmonary arteries in the lungs, most commonly to rule out pulmonary embolism, a serious but treatable condition.
• 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.

Technique

Further information: Contrast CT

In volume renderings, automatic bone removal (used in the right image) is helpful for visualizing the intracranial vessels.

CT angiography is a contrast CT where images taken with a certain delay after injection of radiocontrast to result in a high radiodensity within the blood vessels of interest.

Risks

CT angiography should not be used to evaluate for pulmonary embolism when other tests indicate that there is a low probability of a person having this condition. A D-dimer assay might be a preferred alternative to test for pulmonary embolism, and that test and a low clinical prediction score on the Wells test or Geneva score can exclude pulmonary embolism as a possibility.

Harms of overuse of CT angiography include radiation exposure and the possibility of finding then seeking treatment for a clinically insignificant pulmonary embolism which ought not be treated.

There is a risk of an allergic reaction, which may be serious, whenever contrast material containing iodine is injected. A patient with a history of allergy to x-ray dye may be advised to take special medication for 24 hours before CTA to lessen the risk of allergic reaction or to undergo a different exam that does not call for contrast material injection. CTA should be avoided in patients with kidney disease or severe diabetes, because x-ray contrast material can further harm kidney function. If a large amount of x-ray contrast material leaks out under the skin where the IV is placed, skin damage can result. Compared with other imaging modalities, CTA is associated with a significant dose of ionizing radiation. Depending on patient age and exam protocol, CTA may cause a considerable increase in lifetime cancer risk. However, there are many clinical situations for which the benefits of performing the procedure outweigh this risk.

History

By 1994 CT angiography began to replace conventional angiography in diagnosing and characterizing most cardiovascular abnormalities. Prior to this, conventional angiography had been in use for 70 years.

See also

• Angiography
• Magnetic resonance angiography

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 心臓CTおよび心血管MRIによる非侵襲的冠動脈イメージング noninvasive coronary imaging with cardiac computed tomography and cardiovascular magnetic resonance
• 2. 胸部CTの原理 principles of computed tomography of the chest
• 3. 急性虚血脳卒中の神経画像 neuroimaging of acute ischemic stroke
• 4. 頚動脈狭窄の評価 evaluation of carotid artery stenosis
• 5. 小児における神経画像検査へのアプローチ approach to neuroimaging in children

English Journal

• Coronary Artery Fistulas: Case Series and Literature Review.

• Karazisi C1, Eriksson P, Dellborg M.
• Cardiology.Cardiology.2017 Aug 30;136(2):93-101. [Epub ahead of print]
• Congenital coronary artery fistulas are rare anomalies. As coronary angiography and multidetector computed tomography have become more accessible, they have been increasingly used in the investigation of chest pain and heart failure. Coronary artery fistulas are often an incidental finding, which ra
• PMID 27577264

• The hyperdense basilar artery sign: a case of locked-in syndrome.

• Aryasinghe L1, Kazim Y2, Obeid HF3, Hashim H4.
• International journal of emergency medicine.Int J Emerg Med.2016 Dec;9(1):12. doi: 10.1186/s12245-016-0104-9. Epub 2016 Feb 29.
• BACKGROUND: Locked-in syndrome, although a notoriously famous clinical entity, the rarity of the condition coupled with the variability of clinical features on acute presentation represents a potential diagnostic pitfall for the emergency physician.CASE: A previously healthy 25-year-old female was b
• PMID 26928325

Japanese Journal

• 臨床技術 CTによる冠血流予備量比の解析能に再構成方法が与える影響について (「機能画像」論文特集号)

• 日本放射線技術学会雑誌 = Japanese journal of radiological technology 73(11), 1140-1146, 2017-11
• NAID 40021388897

• Generation and optimization of superpixels as image processing kernels for Jones matrix optical coherence tomography

• Biomedical Optics Express 8(10), 4396-4418, 2017-10
• NAID 120006355831

Related Links

• Computed Tomography (CT) Angiography (Angiogram)

Current and accurate information for patients about Computed Tomography (CT) - Angiography. Learn what you might experience, how to prepare for the exam, benefits, risks and more. ... How should I prepare? You should wear ...

• Computed Tomography Angiogram (CT Angiogram)

A computed tomography angiogram (CT angiogram) is a test that uses X-rays to provide detailed pictures of the heart and the blood vessels that go to the heart,lung,brain,kidneys,head,neck,legs,and arms. A CT angiogram can show ...

Related Pictures

---

★リンクテーブル★

関連記事	「compute」「tomograph」「computed tomography」

「compute」

　　[★]

• v.

• 計算する、算出する、コンピュータ処理する、コンピュータ化する

関

calculate、calculation、computation、computerization、computerize

　

「tomograph」

　　[★]

• 断層撮影、断層撮影機

関

tomographic、tomography

　

「computed tomography」

　　[★] コンピュータ断層撮影 コンピュータ断層撮影法 CT