Computed tomography (CT) of the chest

Computed tomography of the chest organs is considered one of the most informative methods for examining patients with complaints of unpleasant symptoms in this part of the body. In such cases, first of all, doctors prescribe an x-ray to get a general idea of ​​the state of organs and tissues in the chest, and then they prescribe more specific examinations – magnetic resonance or computed tomography. Such techniques reveal violations in the structure and functioning of the organs of the chest and mediastinum: heart, lungs, esophagus, aorta, pulmonary artery, trachea, soft tissues and vessels of various localization.

What are the organs of the chest, what functions do they perform

The chest is not in vain has such a name – it is formed by a “cage” of ribs, the rear ends of which are connected to the thoracic spine, and the front ends to the sternum. From below, the chest cavity is, as it were, supported by the diaphragm. Within this cavity is the heart, lungs, large veins and arteries, trachea, esophagus, nerves, and behind the sternum is the thymus gland.

The heart is the central organ in the circulatory system of the body, it works like a pump, continuously providing blood circulation in the body. The lungs, in turn, are responsible for the processes of oxygen saturation, and perform the respiratory function. They are the largest paired organ of the human body.

The thymus gland is part of the endocrine system, takes part in hematopoiesis and the immune system, regulates growth processes.

The trachea is a tube that consists of cartilaginous half-rings, connective ligaments and muscle tissue on the back wall. Below it is divided into two main bronchi. The main purpose of the trachea is to convey air to the bronchi.

The esophagus is also shaped like a tube that connects the larynx and stomach. Through it, food enters the stomach for digestion.

The essence of computed tomography and why it is necessary to do it

CT is the abbreviation for computed tomography. It is a type of X-ray examination. Through a special method of directed action of X-rays on the human body, the radiologist receives a layered image of the internal organs of the human body, down to the smallest detail, and with the possibility of building a three-dimensional model on the screen.

If you need a more detailed study of deep tissues and structures in the human body, doctors prescribe the use of a contrast agent in the process of tomography. Distributed over tissues, vessels and cavities, the contrast gives the images on the tomograph monitor or the obtained images a clear and well-defined appearance. By the accumulation of contrast in one or another part of the organ, one can judge the presence of functional pathologies or abnormalities in that place.

Computed tomography of the chest is necessary to:

• establish the presence and number of neoplasms in the chest cavity;
• assess the severity of diseases of the organs localized in it;
• develop a treatment plan;
• assess the condition of the lymph nodes in the mediastinum;
• indicate the degree of spread of the neck tumor to the chest organs;
• assess the characteristics of the primary tumor, its ability to spread metastases.

In fact, in addition to the simple rules for preparing for the procedure, tomography itself is a simple and quick method for studying the state of the human body. It is recognized by both doctors and patients as one of the most comfortable and painless methods of examination. After all, the patient is not required to do anything except to take a comfortable lying position, and occasionally hold their breath for a short time. However, this procedure also has its own characteristics.

When is a chest CT scan performed?

Performing a CT scan involves a certain amount of risks, primarily related to the radiation that the patient is exposed to during the scan. Usually, the procedure is performed at the discretion of the attending physician, and in order for a person to be admitted to it, a documented referral with the signature and seal of the doctor will be required. A specialist may consider it appropriate to perform a CT scan in the presence of such indications:

• X-ray negative pneumonia;
• neoplasms of any etiology in the lungs or mediastinal organs;
• metastases in the lymph nodes of the chest, lymphadenopathy, lymphogranulomatosis;
• sarcoidosis, pleurisy, tuberculosis, abscess and parasitic cysts of the lungs, mediastinitis, diseases of the heart and large blood vessels, atelectasis, chest injuries;
• pathological conditions of the bronchi;
• the need to evaluate the effectiveness of the treatment for diseases of the chest;
• preparation for surgical intervention;
• detection on x-rays of changes of unclear etiology;
• clarification of diagnosis;
• the presence of congenital and acquired malformations of the chest organs.

Computed tomography can identify and visualize all the above deviations, if they were not previously indicated and did not manifest themselves in the patient. However, CT is rarely performed as a preventive procedure. For early detection of diseases of the chest, to prevent their development, doctors advise to undergo fluorography once a year. If a person has characteristic symptoms, and the obtained x-ray data indicate the presence of disorders, a chest scan with a tomograph will be quite appropriate.

Contraindications for tomography

It is not always possible to perform CT for the patient. The grounds for prohibiting tomography in a particular case may be:

• the state of pregnancy or the period of breastfeeding (to avoid possible harm to the child);
• the age of the patient is up to 3 years;
• diseases that cause spasms and convulsions (since the subject must remain motionless during the scanning process).

It is not always possible to perform a CT scan for a person with a body weight greater than a certain mark. Conventional tomographs are designed for a weight of no more than 140-180 kg.

For children older than 3 years, a chest CT scan may be ordered at the discretion of the attending physician, however, only if there is a special need. In other cases, a more harmless MRI should be dispensed with.

When using a contrast agent during the study, additional contraindications are added:

• the presence of bronchial asthma or allergies in acute forms;
• intolerance to a contrast agent or iodine;
• severe degree of renal, hepatic and heart failure;

How to Prepare for a Chest CT Scan

Before the patient on a special tomograph table goes directly into the tunnel of the apparatus under the influence of X-rays, the doctor conducts a survey, during which he finds out if there are contraindications for this type of examination, if the person suffers from allergies of any etiology. If the patient has on hand the results of previous studies and previous tests, they must be provided to the doctor for study.

If the procedure is planned without the introduction of a contrast agent, it does not require any special preparation. Otherwise, the doctor will ask you to do a blood test for creatinine in advance. No food or drink should be consumed 2-4 hours before the examination.

The procedure for performing computed tomography of the chest

If it is necessary to scan with contrast, a special iodine-based preparation is administered to the patient intravenously. For this, a syringe or catheter with an automatic injector is used, which passes the substance at a certain speed. After the introduction of an iodine-containing drug, the patient may feel fever, burning, nausea, a rush of blood to the head, and an increase in blood pressure.

Before the procedure begins, all metal objects, jewelry, devices must be removed and left outside the room with the tomograph.

The examination takes place directly inside the tomograph. The subject is placed on the retractable table of the tomograph, where it is most conveniently located. It must be taken into account that movement is prohibited during the scan, so the posture should be relaxed and natural.

The table together with the patient is pushed into the space of the apparatus. The person is there alone, but the doctor watches him from the next room, and can communicate with him. During the tomography, the doctor periodically asks you to hold your breath for a while.

The total duration of the procedure varies from 15 to 30 minutes. If it was carried out with contrast, after its completion, the patient is recommended to drink plenty of fluids so that the drug is quickly excreted from the body. Unpleasant symptoms that may appear due to tomography usually disappear within a day.

Who and how deciphers the results of the survey

The interpretation of the data and the conclusion on them are issued by the radiologist. This medical document will further become the subject of study of doctors of various specialties who can send for such a study: a cardiologist, thoracic surgeon, therapist, pulmonologist, oncologist, etc.

Studying the image displayed by the tomograph on the monitor, the radiologist evaluates the state of the systems of internal organs in the chest and their tissues. In this case, organs and tissues can be examined in different planes, since the image is formed in layers, in thin sections.

Usually, the doctor is ready to give the patient the results of the examination along with his conclusion within an hour. In complex cases, it may take him several hours to decipher the received data and prepare documents. If there are difficulties with the interpretation of the results, experts from related fields can be involved in the process.

In conclusion, the radiologist describes the localization of the pathology, the stage of its development, the features of the course reflected in the images. Based on these data, the attending physician will further develop treatment tactics.

Benefits and possible risks of CT

The advantages of computed tomography over other examination methods are described by physicians and biologists. This technique is non-invasive, so the likelihood of complications after it is extremely low. Patients who have been scanned by a tomograph note that they do not feel pain or discomfort in the process, the only thing that is required of them is to lie quietly on the table, sometimes holding their breath. Technologies of special computer equipment make it possible to obtain a very accurate image with detailed localization of all lesions of the chest organs. In addition, the procedure itself takes only 15-30 minutes, and, in case of detection of acute bleeding or injuries, their detection as quickly as possible allows you to immediately start treatment.

In terms of risks and complications, doctors usually name two main factors that can harm a person’s health as a result of a CT scan. The first of these is the danger of X-ray exposure. However, if the frequency of the procedure does not exceed two times a year, no problems should arise. The second factor relates to tomography with contrast. It is known that the contrast agent can cause acute allergic reactions in patients, so the task of the doctor is to reduce this probability to zero, or to provide him with emergency assistance if an allergy attack has nevertheless begun.

Multilayer computed tomography is the result of decades of development by technicians, engineers, physicists, mathematicians and physicians. Thanks to them, today it is possible to detect the most insignificant, deep-seated pathologies in the systems of the human body, including the organs of the chest. Scanning with a tomograph can detect hidden diseases that are not detected during other types of examinations.