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Computed tomography is a method of studying the structure of the human body. With its help, the skeleton, circulatory system are examined, various pathologies are revealed. CT of blood vessels in medicine is called CT angiography – CTA. This method examines arteries, capillaries, veins, find places of narrowing or blockage. To identify pathologies of the legs, angiography of the lower extremities is prescribed. How it happens, how to prepare, how much it will cost and whether there is a health risk – all this can be found out right now.
Description of the CTA method
The circulatory system is distributed throughout the body and provides life to every cell. Therefore, failures in its work quickly affect the human condition. Diagnosing vascular disease was extremely difficult before the invention of computed tomography. Today, using this method, doctors can examine even small capillaries in detail without a single incision. The essence of CTA is the X-ray scanning of parts of the body. The images created in this case form a 3D model of the circulatory system on a computer monitor.
The innovation of angiography is due to the even greater accuracy of the results than a simple x-ray or conventional CT. For clear images, a special enhancer is used – a contrast agent. This is an iodine-based solution that is injected into a vein under test. The contrast does not let X-rays through, so the circulatory system looks more contrasting in the pictures, with the smallest nuances.
Unlike other diagnostic methods, CTA of the vessels of the lower extremities allows you to reduce the proportion of radiation exposure. This technology uses rays collected in a beam, while the exposure time is as short as possible. For examination, only the lower part of the body is placed in the tomograph chamber, which also reduces the level of exposure to x-rays. The procedure consists of several stages: preparation, introduction of contrast, taking pictures and deciphering the results.
For the patient, the diagnosis is absolutely painless, the only invasion is the intravenous administration of the drug. The tomography process lasts no more than a minute, then the doctor examines the resulting 3D model in detail and writes a conclusion based on it. The patient receives the results in written and electronic form, according to which the attending physician will determine the treatment regimen or further examination.
When is CAT given?
Due to the fact that the technique is based on radiation, albeit minimal, this procedure is prescribed only by a doctor. That is, it is impossible to go through it simply at will, for this there must be a referral from a vascular surgeon or other treating doctor. Indications for such a diagnosis are various disorders in the legs, suspicions of vascular pathology, and patient complaints.
The doctor may issue a referral if the patient experiences:
- pain and lameness after physical exertion, weakness in the limbs, trembling;
- causeless pain in the muscles of the legs;
- numbness of the fingers, feet or individual parts of the limbs;
- coldness in the legs, even when warm.
Also, if the doctor does not feel pulsation during palpation of the lower extremities, this is the reason for CTA. Any suspicion of vascular blockage requires a CT scan, as they often lead to severe complications such as a heart attack.
During the procedure, the radiologist can see various vascular pathologies. Examines the diameter of the vessel, the presence of a lumen or thrombus, finds places of narrowing. Volumetric images of the patient show inflammatory processes in the vessels and adjacent tissues. Due to this, most diseases, even those not related to the circulatory system, can be detected by CTA of the lower extremities.
Such a detailed diagnosis is needed before operations, to confirm the diagnosis or to refute it. When a disease is detected, tomography allows you to control the healing process and adjust the treatment in time. Angiography of the legs is prescribed for:
- atherosclerosis;
- varicose veins;
- trauma to the arteries or veins;
- aneurysm;
- inflammation of the aorta (Takayasu’s disease);
- malignant and benign vascular tumors;
- chronic venous insufficiency;
- swelling of the legs of an unidentified nature;
- arterial thrombosis;
- phlebothrombosis and thrombophlebitis;
- angiopathy in diabetes mellitus.
During the treatment course, the doctor may prescribe one or more tomography procedures. After surgical interventions, they are also referred for CTA, this allows you to consider the results of the operation after some time, prescribe treatment or finish it.
Where can I get this diagnosis?
If the patient is treated in a private clinic, a similar service can also be provided here. In this case, it remains only to set a date and go through the session. It is also possible to undergo diagnostics in public medical institutions, despite the fact that a CT scanner is very expensive equipment. If a doctor from a regular hospital or polyclinic has prescribed a CTA of the vessels of the lower extremities, you need to clarify where exactly you can undergo the study, perhaps it will be a diagnostic center.
You can do this without leaving your home, using the Internet. Such private medical centers always have websites describing services. Here, sometimes the cost is indicated and there is the possibility of online recording. The price for one procedure ranges from $ 100-200, depending on the clinic and the tomograph itself.
Preparing for the procedure
The study of the circulatory system is a very painstaking process, it can be influenced by a number of factors that distort the data. Therefore, doctors recommend preparing in advance. When issuing a referral, the doctor must warn his patient about the ban on taking drugs that reduce blood clotting. Two days before taking it, it is advisable to give up alcohol, since ethyl alcohol sometimes leads to blockage of small capillaries. For 6 hours you need to refuse food, the diagnosis is carried out on an empty stomach. You need to take with you to the reception:
- referral for a procedure from your doctor;
- pictures and results of all previous diagnostics;
- extract from the outpatient card;
- other documents that may be relevant to the disease under study;
- simple drinking water (it will be needed after diagnosis).
Upon arrival at the radiologist’s office, you need to inform him about the concomitant diseases and medications that are taken. So, it must be warned if there is diabetes, pregnancy, an allergy to iodine, the presence of prostheses and implants in the legs.
How would this happen
In the office where the procedure will take place, there is a tomograph. It consists of a special camera that scans the body, and a movable table on which the patient will lie. Before the procedure, the patient is given a change of clothes, asked to remove all metal jewelry. During the diagnostics, the radiologist himself will be in the next room with a window in which he can observe the diagnostic process. Communication is maintained through the speakerphone: the subject hears the doctor and vice versa.
Then the patient lies down on the table and he is injected with contrast. The dye is injected through the injector into the cubital vein, at which time heat can be felt throughout the body – this is a normal reaction that quickly passes. After the introduction of an iodine-containing substance, the tomography process itself begins. The table smoothly enters the chamber, where X-rays pass through the lower limbs along the entire circumference. The data obtained are immediately transferred to a computer and form a 3D model of the circulatory system in the legs.
For the patient, this is the end of the whole procedure, it remains only to change into your clothes and wait for the conclusion of the radiologist. Also, for faster and better removal of contrast from the body, it is recommended to drink plenty of fluids. Deciphering the results takes 15-60 minutes. All diagnostics will require no more than 10-15 minutes. The data is handed over to the patient in the form of a film and a written conclusion, 3D modeling is transferred to an electronic medium: DVD or flash card. These results can be sent by e-mail at the request of the patient.
When is CTA contraindicated?
Like all radiation modalities, computed tomography has its limitations. Almost all contraindications for angiography are due to the use of contrast. This substance contains iodine, which can adversely affect internal organs and systems. In addition, iodine is excreted from the body with urine, but it is able to penetrate, including into breast milk, therefore, for nursing mothers, this procedure is prescribed only in extreme cases.
CT of the vessels of the lower extremities is not performed in such situations:
- the patient is in critical condition;
- with renal failure;
- if there is an allergy to iodine (checked before issuing the appointment);
- the level of keratin in the blood is increased (it is checked before the appointment is issued);
- during pregnancy;
- with diabetes mellitus in the stage of decompensation.
Women during lactation may need CTA, in this case, feeding is stopped for two days after the procedure. Children under 14 years of age are prescribed such a study only in severe cases, usually replacing it with other types. In case of renal failure, such an examination is also avoided, since iodine adversely affects the kidneys. But if the patient’s life is threatened, the doctor may prescribe CTA under strict supervision of kidney function.
People weighing more than 200 kg will need an examination in an open type tomograph. Sometimes the equipment is designed for a weight of no more than 150 kg. When making an appointment by phone or online, it is better to clarify this nuance right away.
Similar diagnostic methods
If CT is contraindicated, use alternative methods of examination. You can replace tomography with MRI – magnetic resonance imaging. Its advantage is that it does not use X-ray irradiation. Pictures are obtained using an electromagnetic response. But this method is absolutely not suitable for those who have metal implants. In addition, the price for such a service is higher than that of KTA. One session will cost 150-250 dollars.
Another new technology is MSCT (multispiral computed tomography). It is also based on X-ray and contrast agent. However, the level of radiation and the amount of dye is less than that of angiography. The results are just as informative, in the form of a 3D image of the circulatory network. Among all research options, this one is the most expensive. For one appointment, you will have to pay 300-350 dollars. Reviews show that in different clinics this price may be higher.
Is KTA dangerous?
Any type of radiation does not have a positive effect on the human body. The exact effect of CT on humans is still not well understood. The radiation used in angiography does not exceed acceptable thresholds. But doctors still do not recommend abusing such examinations. At one time, a person receives such an amount of background radiation that he receives within 2 years from the external environment. However, even this amount does not cause visible damage to health if intervals of 3-6 months are maintained between procedures. To reduce the level of radiation, the patient is not completely placed in the chamber, so the risk is further reduced.
There is a small chance that the contrast will get into the soft tissues outside the vessels. This is accompanied by redness and swelling at the injection site, sometimes painful sensations. But in this case, side effects occur quickly enough and the patient can immediately seek help. If the patient was examined for allergies, all possible contraindications are taken into account – the diagnosis will pass without complications, quickly and comfortably.