Angiography is an imaging test used to evaluate blood vessels, most often arteries. When carrying out angiography, X-rays and shading - contrast agents are used. It makes it possible to find places of abnormal blood flow resulting from many different diseases, and also helps to plan further procedures, and sometimes to implement immediate surgical treatment. It is worth finding out how many possibilities this type of research gives you, what exactly it is about. The article also describes when angiography is performed and the possible risks associated with it.

Angiographyis one of the radiological examinations in which selected elements of the circulatory system are assessed, it can be performed using non-invasive (e.g. CT angiography) or invasive methods (e.g. coronary angiography) ) related to the puncture of the vessel, but allowing simultaneous therapy within a specific vessel.

The principle of angiography is based on the administration of a contrast agent and taking a series of x-rays while filling the vessels with contrast. As a result, the vessels are visible as a uniform shadow that follows their course. Such an image will then be interpreted and on this basis appropriate procedures can be implemented.

Under standard conditions, blood vessels are permeable to X-rays and, in practice, they cannot be visualized by radiation alone. Therefore, when performing angiography, the inside of the vessel is filled with a contrast agent, which is impermeable to X-rays and enables the image of the examined vessel.

Please note that the image obtained reflects the inside of the vessel and only the places where blood flows. In this way, it is impossible to visualize the wall and outer surface of the blood vessel, or places where no contrast flows. After the contrast medium is administered, a series of x-rays is made, the so-called fluoroscopy, which shows the vessel being examined.

Angiography: methods of exercise

Classic angiography - as described earlier, this examination is performed by administering a contrast agent directly to the vessel that we want to image. Then a series of x-rays is taken,which show the flowing contrast, i.e. indirectly the vessel, its branches, possible widenings, vessel breakage and the outflow of contrast, its incorrect flow, or its closure and lack of flow. In this way, venography (phlebography) is performed, where the contrast is administered intravenously and the veins are assessed and, more often, arteriography - the assessment of the arteries and their branches:

  • pulmonary arteries
  • limb arteries
  • abdominal arteries
  • brain arteries

A variation of arteriography is coronary angiography, which is the assessment of the coronary arteries (supplying the heart), in this case long catheters are inserted through the femoral or radial artery, through which the contrast to the coronary arteries is administered. Coronary angiography is an examination that enables and is always performed during coronary angioplasty, i.e. stenting.

The angiography of the brain vessels can be performed in a similar way, then instead of the coronary arteries, the contrast is administered to the internal carotid artery. In this case, the concept of therapy is also possible, e.g. for cerebral aneurysms.

Nowadays - in the age of radiology and interventional cardiology, classic angiography is most often performed as part of an invasive procedure. There are cases where invasive examination is not necessary, and the methods based on tomography, MRI or ultrasound provide a sufficient image. The tests described below are non-invasive methods of vascular imaging and are not considered typical angiography even though they do show the vessels.

  • Computed tomography-angio-TK

The principle of performing the examination is the same as in the case of classic angiography: contrast is administered intravenously, and then after a specified period of time, a computed tomography of the examined area is performed. In this case, it is possible to visualize both arteries and veins, this examination is often used to assess the head vessels or pulmonary arteries in suspected pulmonary embolism.

A variant of this test is Angio-CT of the coronary arteries, unlike coronary angiography, it is a non-invasive method used especially in patients with suspected ischemic heart disease. Unfortunately, it has a lower resolution, is more difficult to interpret and less sensitive than classical angiography.

  • Magnetic resonance imaging-angio-MR

This method is called angiography, but the principle of its implementation is completely different from that of most studies of this type. First of all, it uses magnetic resonance imaging, so there is no X-ray here. Also thanksusing this technique, contrasting agents are rarely used, because MRI itself allows the assessment of vessels, even in the absence of contrast in its light. Angio-MR is most often used to assess the vessels of the brain, and much less frequently it is used to assess the coronary vessels.

  • USG

Ultrasound also allows you to evaluate the vessels. The ultrasound shows, first of all, the structure of the vessel wall and the speed of blood flow, which indirectly indicates the presence of a possible narrowing. Unfortunately, this examination is technically difficult and possible only on vessels available for ultrasonography, so it is not possible to examine e.g. coronary arteries in this way, moreover, the results depend on the transducer application angle and the ultrasound frequency used during the examination.

Classical angiography: indications

Due to its wide diagnostic and therapeutic possibilities, angiography has many applications:

  • diseases of the arteries, e.g. their stenosis in the course of atherosclerosis (ischemic heart disease, lower limb ischemia, carotid stenosis). On this basis, it is assessed whether invasive or conservative - pharmacological treatment is necessary
  • heart attack
  • suspected embolism, e.g. pulmonary embolism
  • developmental defects of blood vessels and their possible correction
  • deep vein thrombosis
  • diagnosis of cerebrovascular diseases, e.g. aneurysms

Classical angiography: waveform

These tests are performed in the invasive radiology laboratory or in the hemodynamics laboratory (in the case of coronary angiography), the operator is most often a radiologist, vascular surgeon or cardiologist, depending on the type of examination.

Blood tests are performed prior to angiography, including a complete blood count and creatinine, to check your kidney function for contrast.

Further preparation for the procedure involves nursing activities - insertion of a cannula, shaving the vascular access sites and their disinfection, the last of them is performed in the room immediately before the procedure.

Fasting for the treatment.

The angiography itself begins with local anesthesia in the area of ​​vascular access - in the groin or wrist. Then, after puncturing the vessel, a catheter is inserted into the vessel, which leads to the vessel that is the target of angiography. The position of the catheter is assessed using x-rays. Then the contrast is administered, which mixes with the blood and fills the examined vessels, enabling its visualization.

The result is a short film - a series of serial X-ray photos, it is saved in the versiondigital so that you can come back to it later. After the images are captured, the examination can be completed or a cardiology or interventional radiology procedure can be performed. Then the catheter is removed and a pressure dressing is applied to the puncture site.

Angiography: possible complications

Any type of angiography is a safe test and complications are rare. If tomography or MRI is performed, the only risk is the administration of contrast - allergic reactions may occur in allergic people, and in the case of kidney diseases - their damage. Both of these complications can be adequately prevented if the doctor preparing for the procedure is informed about hypersensitivity to contrast or kidney disease.

Both kidney damage and allergic reaction can also occur in the course of classic angiography.

Other complications may be related to the site of the catheter insertion - vascular access, they may be hematomas and bruises, or vascular damage.

More serious events occur exceptionally and vary depending on the examined area of ​​the body and the type of examination, they may be:

  • heart attack
  • rhythm disturbance
  • stroke

However, the risk of complications always outweighs the benefits obtained during the tests, allowing on the one hand diagnosis and further appropriate treatment, and on the other, often immediate treatment in the event of vessel damage or narrowing.

Angiography: contrast agents

The contrast agents used in classical angiography and CT angiography contain iodine. This element is non-toxic, and at the same time by absorption it weakens the transmission of X-rays, which ensures a contrasting effect. This keeps the area containing the shader darker than the rest of the image, allowing you to judge it.

Iodine contrast can be ionic or non-ionic, the former is slightly more toxic and poses a risk of kidney damage in people with kidney disease, therefore non-ionic agents are used in such cases.

In an MRI scan, if contrast agents are used, they are completely different compounds, not containing iodine, and their structure is based on gadolinium.

About the authorBow. Maciej GrymuzaA graduate of the Faculty of Medicine at the Medical University of K. Marcinkowski in Poznań. He graduated from university with an over good result. Currently, he is a doctor in the field of cardiology and a doctoral student. He is particularly interested in cardiologyinvasive and implantable devices (stimulators).

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