Angiography

Angiography is one of the methods of modern diagnostics. This is a contrast x-ray examination of blood vessels. Angiography is used in fluoroscopy, radiography, computed tomography, hybrid operating rooms (operating theater for medical imaging). Diagnostics determines the functionality of the vessels, the state collateral blood flow, the extent of the pathological process and its features. What you need to know about the diagnosis, what are the indications / contraindications and is it possible to decipher the diagnosis yourself?

General characteristics of the study

Angiography is a method of diagnosing blood vessels, which is based on the properties of x-rays. Research can be general or selective. With the help of general angiography, all the vessels of the human body can be examined. The selective method is necessary for contrasting  and visualization certain vessels.

There are two methods of angiography – computed tomography and magnetic resonance imaging. CT allows you to get a clear picture of the blood vessels, to assess the nature of the blood flow. The information obtained is analyzed using special image reconstruction algorithms. With MRI, which, unlike CT, does not use x-rays, also receive an image of blood vessels, but the device reveals both functional and anatomical features of blood flow. The choice of diagnostic method depends on the characteristics of the patient’s health and the degree of damage to the body.

The study is divided into two types – puncture and catheterization. What does this mean and which method should be preferred? Puncture is used for superficial vessels. The contrast agent can be injected directly through a special syringe.

A contrast agent is a drug that is injected into an organ / bloodstream / body cavity. It provides contrast enhancement (staining) in radiological examination. The substance helps to visualize the vascular bed, internal relief vessels.

There are two large groups of contrast agents – iodine-containing (water- or fat-soluble) and water-insoluble. Angiography uses iodine-containing contrast agents. They are divided into ionic and non-ionic substances. The non-ionic contrast agent is suitable for intravascular administration and is considered the safest. It is superior to ionic drugs in lesser the risk of adverse reactions and lower cost.

The second type of angiography is catheterization. The method is used if the artery or vein to be examined is located deep under the skin. Before starting the diagnosis, the doctor injects the patient with anesthesia. Then an incision is made on the skin/subcutaneous tissue, the desired vessel is found and the sheath is inserted into it. The introducer is a thin plastic tube with a diameter of 10 centimeters or less. A catheter and other necessary instruments are placed inside the tube. The introducer is used to protect blood vessels from various damages. The catheter itself looks like a long thin hose. Through it, a contrast agent is injected into a specific vessel.

As soon as an iodine-containing drug is ingested, it spreads with the blood stream in the following sequence: large arteries – small arterioles – capillaries – small venules – large veins. While the substance is moving through the human body, the device takes a series of x-rays. It is these pictures that are the purpose of the diagnosis – according to them, the doctor determines the norms and pathologies of the vessels. The rate of spread of the contrast agent is indicative of the rate of blood flow. All information received is recorded on a digital medium and transmitted to the patient. The results of the study may also be useful to other specialists.

The doctor tries to perform the angiography as quickly as possible in order to reduce the patient’s exposure to the x-rays.

Applications of angiography

Diagnostics is used in the following areas of medicine:

• oncology (to detect cancerous neoplasms / their metastases, in which an extensive capillary network is formed);
• neurology (to detect aneurysms, hematomas, oncology, bleeding in vessels brain);
• phlebology (to determine the location of narrowing / blockage of veins, their congenital diseases, atherosclerotic pathologies or blood clots);
• pulmonology (to detect malformations of the lungs or sources of bleeding);
• vascular surgery (used during preparation for operations on the vessels to clarify their structure, location and features).

Indications and contraindications for the procedure

Doctors recommend replacing CT-angiography for MRI angiography or ultrasound only when the procedure could seriously aggravate the patient’s condition or cause complications. X-ray diagnostics is strictly contraindicated for pregnant women, since radiation can cause abnormalities in the development of the fetus and disrupt the normal course of pregnancy. Also contraindications include:

1. Acute infectious/inflammatory diseases. With angiography, the risk of bacteria and viruses entering the blood is as high as possible. This will increase the risk of vascular infection, suppuration at the point of introduction of the catheter.
2. Severe heart failure. Diagnosis affects blood pressure and can provoke its sharp jumps, which is undesirable for heart disease. Additionally, the patient may be worried, which will cause interruptions in cardiac activity.
3. Renal / liver failure (including decompensated). An iodine-containing drug affects the kidneys, more precisely, the excretion of urine, while delaying the contrast substance inside the body. Moreover, the combination of stress and contrast agent can be fraught with hepatic coma.
4. Individual intolerance to the drug. A patient allergic to iodine may experience a severe allergic reaction in the form of toxic bullous dermatitis, anaphylacticic shock or angioedema.
5. Violation of blood clotting. With increased blood clotting, the risk of thrombus formation is high, with reduced blood clotting, the risk of bleeding.
6. Mental pathologies. During the angiography, the patient is conscious. Moreover, he must follow some instructions from doctors, constantly report on his own well-being and feelings. A mentally ill person will not be able to do this, and additional stress will only aggravate the situation.
7. Thrombophlebitis. The contrast agent can enhance the inflammatory process in the vein and provoke occlusion of the vessel / separation of a blood clot.

Features of preparation for the procedure

Before diagnosis, the presence of contraindications is excluded, fluorography, electrocardiography are performed to monitor the patient’s condition. Two weeks before the angiography, it is necessary to completely exclude alcohol so as not to distort the overall result. In some cases, the doctor performs hydration (saturation of the body with fluid) to dilute the contrast agent, facilitate its removal from the body and minimize the harmful effects on the liver.

To reduce the risk of an allergic reaction, the doctor prescribes antiallergic drugs immediately before the procedure. 4 hours before the angiography, you can not eat food and various liquids. Before the examination, the patient must remove jewelry, remove all metal objects, as they prevent the free passage of x-rays. Then the specialist determines the area of ​​uXNUMXbuXNUMXbthe passage, shaves on the skin of this area hair and cleans the intervention area.

Before starting an angiography, the doctor must obtain written consent from the patient for the procedure.

The principle of diagnostics

Angiography, regardless of the type and area of ​​​​diagnosis, is carried out according to a single scheme. First, the doctor intramuscularly injects a tranquilizer and an antihistamine. They are necessary for the general reduction of anxiety, the prevention of a pathogenic reaction to a contrast agent. The skin area (under which the necessary vessel is located) is treated with an antiseptic preparation, an anesthetic is injected subcutaneously, and then a small incision is made.

An introducer and a catheter are inserted into the incision made. Previously, a special solution is injected into the test vessel to prevent spasm and minimize the irritating effect of the contrast agent. The catheter is advanced through the introducer to the desired vessel under the control of the x-ray machine. As soon as the goal is achieved, a contrast agent is injected through the catheter and the image is taken. In some cases, this step is repeated 2-3 times.

After collecting information, the catheter and introducer are removed from the body. Then the doctor stops the bleeding (it opens due to the traumatization of the vessels with a tube), applies a sterile pressure bandage and instructs. For the next 6-10 hours after the procedure, bed rest should be observed to minimize the risk of blood clots.

Deciphering the diagnosis

Angiography should be interpreted by an experienced specialist. – radiologist. In case of doubt, consultation of another specialist – vascular surgeon. Do not prescribe treatment yourself and do not try to diagnose the condition from information on the Internet. Strictly follow the doctor’s instructions and follow the therapeutic course.

Possible side effects

Side effects depend on the chosen technique and the field of study. Let’s analyze some manifestations on specific examples. During an angiography of the vessels of the brain/limbs, the patient is given anesthesia. This is necessary to anesthetize the insertion site of the catheter and introducer. The patient will not feel pain during the advancement of the catheter, since the inner vascular wall is devoid of pain receptors. After the introduction of an iodine-containing substance, the patient may feel a metallic taste in the mouth, heat or a growing feeling of warmth, which gradually covers the whole body. Most often, the symptoms go away on their own within a few minutes.

Angiography of the coronary vessels may cause a sensation of heat. The highest temperature is recorded in the face area. If the catheter touches the heart walls, the heart rhythm fails, blood pressure drops, so the patient may experience mild discomfort, dizziness, cough, or nausea. These side effects need to be corrected. Let your doctor know how you feel and follow his instructions.

In medical practice, there are rarely any side effects after angiography. The main thing is to track contraindications, identify a risk group and carry out diagnostics only in the direction of a doctor. Normally, an iodine-containing drug is excreted from the body naturally. Excretion occurs through the kidneys and takes 1 – 1,5 days (average figure, which may vary). Experts say that the process can be accelerated – it is enough to increase the volume of fluid intake. Immediately after angiography, the patient needs bed rest. The recovery period may be different for each group of patients. Additional information should be clarified with the attending physician.

Angiography has been known since the XNUMXth century, but only a few have entered everyday practice. so long ago. Now the method helps to identify, prevent and select high-quality treatment for diseases of the vascular system. The cost of diagnostics varies depending on the technique, the area under study and the chosen medical institution. The study is prescribed by the attending physician, based on the patient’s condition and the needs of the body. Clearly follow the therapeutic course and be healthy.