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Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the
arteries An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the p ...
,
vein Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenate ...
s, and the heart chambers. Modern angiography is performed by injecting a radio-opaque
contrast agent A contrast agent (or contrast medium) is a substance used to increase the contrast of structures or fluids within the body in medical imaging. Contrast agents absorb or alter external electromagnetism or ultrasound, which is different from radiop ...
into the blood vessel and imaging using X-ray based techniques such as
fluoroscopy Fluoroscopy () is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope () allows a physician to see the internal structure and function ...
. The word itself comes from the
Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. ** Proto-Greek language, the assumed last common ancestor ...
words ἀγγεῖον ''angeion'' 'vessel' and γράφειν ''graphein'' 'to write, record'. The film or image of the
blood vessel The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away f ...
s is called an ''angiograph'', or more commonly an ''angiogram''. Though the word can describe both an arteriogram and a venogram, in everyday usage the terms angiogram and arteriogram are often used synonymously, whereas the term venogram is used more precisely. The term angiography has been applied to radionuclide angiography and newer vascular imaging techniques such as CO2 angiography, CT angiography and MR angiography. The term ''isotope angiography'' has also been used, although this more correctly is referred to as isotope perfusion scanning.


History

The technique was first developed in 1927 by the Portuguese physician and neurologist Egas Moniz at the
University of Lisbon The University of Lisbon (ULisboa; pt, Universidade de Lisboa, ) is a public research university in Lisbon, and the largest university in Portugal. It was founded in 2013, from the merger of two previous public universities located in Lisbon, th ...
to provide contrasted X-ray
cerebral angiography Cerebral angiography is a form of angiography which provides images of blood vessels in and around the brain, thereby allowing detection of abnormalities such as arteriovenous malformations and aneurysms. It was pioneered in 1927 by the Portugues ...
in order to diagnose several kinds of nervous diseases, such as tumors, artery disease and arteriovenous malformations. Moniz is recognized as the pioneer in this field. He performed the first cerebral angiogram in Lisbon in 1927, and
Reynaldo dos Santos Reynaldo dos Santos (3 December 1880 – 6 May 1970) was a Portuguese physician, writer, and art historian. As a physician, he was a pioneer in the fields of vascular surgery and urology; as an art historian, he published numerous works on 15th- ...
performed the first aortogram in the same city in 1929. In fact, many current angiography techniques were developed by the Portuguese at the University of Lisbon. For example, in 1932, Lopo de Carvalho performed the first pulmonary angiogram via venous puncture of the superior member. In 1948 the first cavogram was performed by
Sousa Pereira Sousa refers to * John Philip Sousa (1854–1932), American composer of marches Sousa also may refer to: People * Sousa (surname), including other Portuguese variants such as Souza, de Sousa, D'Souza, etc. * João Sousa, Portuguese tennis pla ...
. Radial access technique for angiography can be traced back to 1953, where Eduardo Pereira first cannulated the radial artery to perform a coronary angiogram. With the introduction of the
Seldinger technique The Seldinger technique, also known as Seldinger wire technique, is a medical procedure to obtain safe access to blood vessels and other hollow organs. It is named after Sven Ivar Seldinger (1921–1998), a Swedish radiologist who introduced th ...
in 1953, the procedure became markedly safer as no sharp introductory devices needed to remain inside the vascular lumen.


Technique

Depending on the type of angiogram, access to the blood vessels is gained most commonly through the
femoral artery The femoral artery is a large artery in the thigh and the main arterial supply to the thigh and leg. The femoral artery gives off the deep femoral artery or profunda femoris artery and descends along the anteromedial part of the thigh in the f ...
, to look at the left side of the heart and at the arterial system; or the jugular or femoral vein, to look at the right side of the heart and at the venous system. Using a system of guide wires and catheters, a type of
contrast agent A contrast agent (or contrast medium) is a substance used to increase the contrast of structures or fluids within the body in medical imaging. Contrast agents absorb or alter external electromagnetism or ultrasound, which is different from radiop ...
(which shows up by absorbing the X-rays), is added to the blood to make it visible on the X-ray images. The X-ray images taken may either be still, displayed on an image intensifier or film, or motion images. For all structures except the heart, the images are usually taken using a technique called
digital subtraction angiography Digital subtraction angiography (DSA) is a fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a "pre-contra ...
or DSA. Images in this case are usually taken at 2–3 frames per second, which allows the interventional radiologist to evaluate the flow of the blood through a vessel or vessels. This technique "subtracts" the bones and other organs so only the vessels filled with contrast agent can be seen. The heart images are taken at 15–30 frames per second, not using a subtraction technique. Because DSA requires the patient to remain motionless, it cannot be used on the heart. Both these techniques enable the interventional radiologist or cardiologist to see
stenosis A stenosis (from Ancient Greek στενός, "narrow") is an abnormal narrowing in a blood vessel or other tubular organ or structure such as foramina and canals. It is also sometimes called a stricture (as in urethral stricture). ''Stricture' ...
(blockages or narrowings) inside the vessel which may be inhibiting the flow of blood and causing pain. After the procedure has been completed, if the femoral technique is applied, the site of arterial entry is either manually compressed, stapled shut, or sutured in order to prevent access-site complications.


Uses


Coronary angiography

One of the most common angiograms performed is to visualize the blood in the coronary arteries. A long, thin, flexible tube called a
catheter In medicine, a catheter (/ˈkæθətər/) is a thin tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. Ca ...
is used to administer the X-ray contrast agent at the desired area to be visualized. The catheter is threaded into an artery in the
forearm The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in a ...
, and the tip is advanced through the arterial system into the major coronary artery. X-ray images of the transient
radiocontrast Radiocontrast agents are substances used to enhance the visibility of internal structures in X-ray-based imaging techniques such as computed tomography ( contrast CT), projectional radiography, and fluoroscopy. Radiocontrast agents are typically ...
distribution within the blood flowing inside the coronary arteries allows visualization of the size of the artery openings. The presence or absence of
atherosclerosis Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no sy ...
or
atheroma An atheroma, or atheromatous plaque, is an abnormal and reversible accumulation of material in the inner layer of an arterial wall. The material consists of mostly macrophage cells, or debris, containing lipids, calcium and a variable amount ...
within the walls of the
arteries An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the p ...
cannot be clearly determined. Coronary angiography can visualize coronary artery
stenosis A stenosis (from Ancient Greek στενός, "narrow") is an abnormal narrowing in a blood vessel or other tubular organ or structure such as foramina and canals. It is also sometimes called a stricture (as in urethral stricture). ''Stricture' ...
, or narrowing of the blood vessel. The degree of stenosis can be determined by comparing the width of the lumen of narrowed segments of blood vessel with wider segments of adjacent vessel.


Cerebral angiography

Cerebral angiography provides images of blood vessels in and around the brain to detect abnormalities, including
arteriovenous malformation Arteriovenous malformation is an abnormal connection between arteries and veins, bypassing the capillary system. This vascular anomaly is widely known because of its occurrence in the central nervous system (usually cerebral AVM), but can a ...
s and
aneurysm An aneurysm is an outward bulging, likened to a bubble or balloon, caused by a localized, abnormal, weak spot on a blood vessel wall. Aneurysms may be a result of a hereditary condition or an acquired disease. Aneurysms can also be a nidus ( ...
s. One common cerebral angiographic procedure is neuro-vascular
digital subtraction angiography Digital subtraction angiography (DSA) is a fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a "pre-contra ...
.


Pulmonary angiography

Pulmonary angiography is used to visualise the anatomy of pulmonary vessels.


Peripheral angiography

Angiography is also commonly performed to identify vessels narrowing in patients with leg claudication or ''cramps'', caused by reduced blood flow down the legs and to the feet; in patients with renal stenosis (which commonly causes high blood pressure) and can be used in the head to find and repair stroke. These are all done routinely through the femoral artery, but can also be performed through the brachial or axillary (arm) artery. Any stenoses found may be treated by the use of balloon angioplasty, stenting, or atherectomy.


Fluorescein angiography

Fluorescein angiography is a medical procedure in which a fluorescent dye is injected into the bloodstream. The dye highlights the blood vessels in the back of the eye so they can be photographed. This test is often used to manage eye disorders.


OCT angiography

Optical coherence tomography (OCT) is a technology using
near-infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
light to image the eye, in particular penetrate the retina to view the micro-structure behind the retinal surface. ocular OCT angiography (OCTA) is a method leveraging OCT technology to assess the vascular health of the retina.


Microangiography

Microangiography is commonly used to visualize tiny blood vessels.


Post mortem CT angiography

Post mortem CT angiography for medicolegal cases is a method initially developed by the Virtopsy group. Originating from that project, both watery and oily solutions have been evaluated. While oily solutions require special deposition equipment to collect waste water, watery solutions seem to be regarded as less problematic. Watery solutions also were documented to enhance post mortem CT tissue differentiation whereas oily solutions were not. Conversely, oily solutions seem to only minimally disturb ensuing toxicological analysis, while watery solutions may significantly impede toxicological analysis, thus requiring blood sample preservation before post mortem CT angiography.


Complications

After an angiogram, a sudden shock can cause a little pain at the surgery area, but heart attacks and strokes usually don't occur, as they may in bypass surgery.


Cerebral angiography

Major complications in cerebral angiography such as in
digital subtraction angiography Digital subtraction angiography (DSA) is a fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a "pre-contra ...
or contrast MRI are also rare but include
stroke A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop function ...
, an allergic reaction to the anaesthetic other medication or the contrast medium, blockage or damage to one of the access veins in the leg, pseudoaneurysm at the puncture site; or
thrombosis Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (thr ...
and embolism formation.
Bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, v ...
or
bruising A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur clos ...
at the site where the contrast is injected are minor complications, delayed bleeding can also occur but is rare.


Additional risks

The contrast medium that is used usually produces a sensation of warmth lasting only a few seconds, but may be felt in a greater degree in the area of injection. If the patient is allergic to the contrast medium, much more serious side effects are inevitable; however, with new contrast agents the risk of a severe reaction is less than one in 80,000 examinations. Additionally, damage to blood vessels can occur at the site of puncture/injection, and anywhere along the vessel during passage of the catheter. If
digital subtraction angiography Digital subtraction angiography (DSA) is a fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a "pre-contra ...
is used instead, the risks are considerably reduced because the catheter does not need to be passed as far into the blood vessels; thus lessening the chances of damage or blockage.


Infection

Antibiotic prophylaxis An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
may be given in those procedures that are not clean, or clean procedures that results in generation of infarcted or
necrotic Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dig ...
tissues such as embolisation. Routine diagnostic angiography is often considered a clean procedure. Prophylaxis is also given to prevent infection from infected space into blood stream.


Thrombosis

There are six risk factors causing thrombosis after arterial puncture: low blood pressure, small arterial diameter, multiple puncture tries, long duration of cannulation, administration of vasopressor/inotropic agents, and the usage of catheters with side holes.


See also

*
Angiosarcoma Angiosarcoma is a rare and aggressive cancer that starts in the endothelial cells that line the walls of blood vessels or lymphatic vessels. Since they are made from vascular lining, they can appear anywhere and at any age, but older people are ...
* Cardiac catheterization *
Computed tomography angiography Computed tomography angiography (also called CT angiography or CTA) is a computed tomography technique used for angiography—the visualization of arteries and veins—throughout the human body. Using contrast injected into the blood vessels, im ...
*
Contrast medium A contrast agent (or contrast medium) is a substance used to increase the contrast of structures or fluids within the body in medical imaging. Contrast agents absorb or alter external electromagnetism or ultrasound, which is different from radiop ...
*
Echocardiogram An echocardiography, echocardiogram, cardiac echo or simply an echo, is an ultrasound of the heart. It is a type of medical imaging of the heart, using standard ultrasound or Doppler ultrasound. Echocardiography has become routinely used in t ...
* Electrocardiogram * Fluorescein angiography * Image intensifier *
Interventional radiology Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs bo ...
*
Intravascular ultrasound Intravascular ultrasound (IVUS) or intravascular echocardiography is a medical imaging methodology using a specially designed catheter with a miniaturized ultrasound probe attached to the distal end of the catheter. The proximal end of the cathe ...
* Intravenous digital subtraction angiography * Magnetic resonance angiography * Peripheral artery occlusive disease


References


External links


RadiologyInfo
for patients: Angiography procedures

from Angioplasty.Org
C-Arms types
Several types of C-Arms
Coronary CT angiography by Eugene Lin
{{Authority control Vascular procedures Projectional radiography