Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, blood vessels and organs, with particular interest in the arteries, veins and heart chambers. This is traditionally done by injecting a radio-opaque contrast agent into a vein and imaging using an X-ray-based technique such as fluoroscopy.
The word itself comes from the Greek word ??????? angeion , "ship", and ??????? graphein , "to write" or "record". The film or blood vessel image is called angiography, or more commonly the angiogram . Although the word can describe both arteriogram and venogram , in everyday use the term angiogram and arteriogram are often used synonymously, while the term venogram is used more precisely.
The term angiography has been applied to radionuclide angiography and newer vascular imaging techniques such as CT angiography and MR angiography. The term isotope angiography has also been used, although this is more accurately described as isotope perfusion scanning.
Video Angiography
Histori
This technique was first developed in 1927 by Portuguese physician and neurologist Egas Moniz at the University of Lisbon to provide contrasting contrast angiography angiography to diagnose several types of neurological diseases, such as tumors, arterial disease and arterial malformations. Moniz is recognized as a pioneer in this field. He performed the first cerebral angiogram in Lisbon in 1927, and Reynaldo Cid dos Santos undertook the first aortogram in the same city in 1929. In fact, many angiography techniques are currently developed by the Portuguese at the University of Lisbon. For example, in 1932, Lopo de Carvalho performed the first pulmonary angiogram through a vein puncture of the superior member; in 1948, the first cavogram was performed by Sousa Pereira. Radial access techniques for angiography can be traced back to 1953, where Eduardo Pereira first synthesized the radial artery to perform a coronary angiogram. With the introduction of the Seldinger technique in 1953, the procedure became very safe because there was no sharp delivery device required to remain within the vascular lumen.
Maps Angiography
Technique
Depending on the type of angiogram, access to the blood vessels is obtained most often through the femoral artery, to see the left side of the heart and to the arterial system; or jugular or femoral vein, to see the right side of the heart and the venous system. Using a guide wiring system and a catheter, a type of contrast agent (which appears by absorbing X-rays), is added to the blood to make it visible on an x-ray image.
The captured X-ray image may still be silent, displayed on intensive images or movies, or moving images. For all structures except the heart, images are usually taken using a technique called digital subtraction angiography or DSA. Images in this case are usually taken at 2 - 3 frames per second, allowing radiologist interventions to evaluate blood flow through the vessels or blood vessels. This technique "reduces" bones and other organs so that only vessels filled with visible contrast agents. Heart images taken at 15-30 frames per second, do not use reduction techniques. Because DSA requires the patient to remain immobilized, it can not be used on the heart. Both of these techniques allow an interventional radiologist or cardiologist to look at stenosis (blockage or narrowing) inside a blood vessel that might inhibit blood flow and cause pain.
Usage
Coronary angiography
One of the most commonly performed angiograms is visualizing blood in the coronary arteries. A long, thin, flexible tube called a ram catheter is used to set the X-ray contrast agent in the desired area to be visualized. The catheter is threaded into the artery in the forearm, and the tip is passed through the arterial system to the major coronary artery. The X-ray image of the transient radiocontrast distribution in the blood flowing inside the coronary arteries allows visualization of the size of the arterial openings. The presence or absence of atherosclerosis or atheroma in artery walls can not be clearly determined. See coronary catheterization for more detail.
To detect coronary artery disease, Computed Tomography (CT) Scan is better than Magnetic Resonance Imaging (MRI). The sensitivity and specificity between CT and MRI were (97.2 percent and 87.4 percent) and (87.1 percent and 70.3 percent), respectively. Therefore, CT (especially multislice CT) is more acceptable, more widely available, preferably patient, and more economical. In addition, CT takes shorter breathing time than MRI.
Fluorescein angiography
Fluorescence angiography is a medical procedure in which fluorescent dye is injected into the bloodstream. Dyes highlight the veins behind the eyes so they can be photographed. This test is often used to manage eye disorders. Ocular OCTA (OCTA) ocular imaging technique, currently being developed to simulate fluorescence angiography results without the need to inject intravenous dye into the patient.
Microangiography
Micrography is generally used to visualize small blood vessels.
Neuro-vascular angiography
Another increasingly common angiography procedure is neuro-vascular digital angiography angiography to visualize the supply of arteries and veins to the brain. Interventions work like anile coil-embolization and AVM adhesion can also be performed.
Peripheral angiography
Angiography is also commonly used to identify narrowed vessels in patients with foot or cramp legacy, caused by reduced blood flow to the feet and legs; in patients with renal stenosis (which usually causes high blood pressure) and can be used in the head to find and repair strokes. This is all done routinely through the femoral artery, but can also be done through the brachial or axillary artery (arm). Any stenosis found can be treated using atherectomy. Post-mortem angiography for post-mortem case
Post mortem CT angiography for medicolegal cases is a method initially developed by the Virtopsy group. Coming from the project, a watery and oily solution has been evaluated.
While oily solutions require special deposition equipment to collect wastewater, aqueous solutions seem to be considered to be less problematic. Aqueous solutions are also documented to increase the differentiation of post mortem CT tissue while the oily solution is not. In contrast, oily solutions seem to only slightly interfere with subsequent toxicological analysis, while aqueous solutions can significantly inhibit toxicological analysis, thus requiring preservation of blood samples prior to post-mortem CT angiography.
Complications
After the angiogram, sudden shock may cause slight pain in the surgical area, but heart attacks and strokes usually do not occur, as they may be in bypass surgery. A heart attack occurs when blood flow to the heart is blocked, usually by a blood clot. Without oxygenated blood, the heart muscle begins to die. A stroke is a brain attack, cutting off important blood flow and oxygen to the brain. A stroke occurs when blood vessels that feed the brain are blocked or bursts.
Cerebral angiography
Major complications in cerebral angiography such as subversion reduction or contrast MRI angiography are also rare, but include stroke, allergic reactions to other anesthetic agents or contrast media, blockage or damage to one access vein in the leg, or thrombosis and embolism. Bleeding or bruising at contrast sites injected is a minor complication, delayed bleeding can also occur but is rare.
Additional risk
The contrast medium used usually results in a warmth sensation that lasts only a few seconds, but may be felt in a larger degree in the injection area. If patients are allergic to contrast media, far more serious side effects can not be avoided; however, with a new contrast agent, the risk of a severe reaction is less than one in 80,000 checks. In addition, blood vessel damage can occur at the puncture/injection site, and anywhere along the ship during the catheter journey. If digital reduction angiography is used instead, the risk is greatly reduced because the catheter need not be passed as far as the blood vessels; thereby reducing the possibility of damage or blockage.
See also
- Cardiac catheterization
- Computed tomography angiography
- Contrast media
- Echocardiogram
- Electrocardiogram
- Fluorescence angiography
- Intensifier image
- Interventional radiology
- Intravascular ultrasound
- Intravenous digital angiography reduction
- Magnetic resonance angiography
- Peripheral arterial occlusion disease
References
External links
- RadiologyInfo for patient: angiography procedure
- Catheterization of the Heart from Angioplasty.Org
- Type C-Arms Certain types of C-Arms
- Angiography Equipment from Siemens Medical
- Society for Cardiovascular and Interventional Radiology Europe
- CT coronary angiography by Eugene Lin
Source of the article : Wikipedia
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