Today, almost everyone has heard about CT scans, thanks to its popularity. But to those to whom it is appointed, it is important to know in detail: what is CT and the principle of its operation.

General information

Computer tomography (CT) is a modern layered study of the human body. It is based on computer measurement and processing of the difference in attenuation of X-ray radiation by tissues of different density. With the help of computed tomography, the organ under examination is visible at different angles, so you can get its image in all projections and in a three-dimensional view.

A special X-ray computer tomograph is used for CT. It includes a movable table entering the patient into the opening of the scanning unit, in which there are radiation sensors and an X-ray tube.

What is CT? CT of the spineX-rays pass through the human organ under investigation, radiation becomes weaker when passing through tissues. Rotating at an angle of 360 degrees around the patient, the radiator of the X-rays scans the area of ​​his body under different angles. At this time, the sensors located on the other side of the patient are engaged in converting the radiation energy into electrical pulses. Then they go through computer processing, the result of which is visible on the monitor. The received images are studied and analyzed by the radiologist, then recorded on a storage medium and printed on a film. The entire research process takes no more than 10 minutes, but depending on the tomograph and the specificity of the diagnosed area, it is required up to half an hour.

Recommendations before and after the examination

Patients who have been assigned CT scans want to know what CT is, what recommendations should be followed before, during, and after the procedure. For all types of scanning, it is recommended to give up food and drink 2 hours before the test.For the diagnosis of certain organs and in some cases by the doctor's decision, an intravenous contrast medium is required to improve the results of the study. This will be reported to each patient by the attending doctor or medical personnel of the CT cabinet.

It is important to know that if a patient has electrical, mechanical and magnetic implants (prostheses, plates made of metal, pacemakers), one day before CT there were studies using barium suspension, and during pregnancy, it is necessary to inform the doctor about it.

The investigated part of the body should be without clothes and ornaments. During the examination, for reliability of the result, it is necessary to lie motionless, it may be necessary to hold the breath for several seconds. Computed tomography is an absolutely painless examination.

After CT with intravenous administration of the drug for its early removal from the body, it takes two hours to take up to 2 liters of water.

What are the indications for the use of CT?

Computed tomography is used routinely, emergency cases, medical-diagnostic manipulations, for example, to control the conduct of punctures.

As a screening test, CT should be done with frequent headaches, especially accompanied by vomiting, periodic loss of consciousness or convulsions, head injuries, and to exclude oncological formations.

In urgent order, the study is conducted in case of serious injuries, suspicions of vital organ and vessel injuries, and diagnosis of cerebral hemorrhage.

When do CT of the abdominal cavity?

Computed tomography of the abdominal space is used for accurate diagnosis of diseases of the spleen, gall bladder, liver, pancreas, stomach, thenof the intestine.

CT of the abdominal cavity is mainly performed with intravenous injection of contrast medium, since the soft tissues of the organs are complex for diagnosis. Contrast, which has a property in an unequal degree to accumulate in various tissues, makes it possible to distinguish organs from each other, which favors an accurate diagnosis.

Symptoms in which doctors recommend CT scan of the abdominal cavity: frequent pain in the abdomen, yellowing of the skin and sclera, anemia, sudden weight loss, the formation of an incomprehensible nature, revealed by ultrasound.

When do computer tomography of the spine?

This study is widely used to diagnose diseases of the thoracic, cervical and lumbar spine. It provides an opportunity to assess simultaneously the structure of bones, blood vessels and soft tissues and obtain a three-dimensional image.

  • any injuries of the spine;
  • diagnosis of congenital anomalies;
  • diseases of the spinal cord of an infectious nature;
  • arthritis, osteoporosis;
  • study of the causes of pain syndrome (spine change, disc herniation);
  • tumor or metastasis from neighboring organs.

It should be noted that even after an insignificant at first glance injury in the spine, as well as any pain in the lower back that gives to one of the lower limbs, it is necessary to urgently consult a doctor. Only the doctor after the examination of the patient can decide on the need for computer tomography.

What are the indications for computed tomography of the chest?

A computer tomograph is successfully used to diagnose diseases of the cardiovascular system, bones and ribs of the thoracic spine, assessment of the lungs. CT of the thorax is needed in diagnosis:

  • tuberculosis;
  • heart condition (presence of tumors, cysts, wall thickness);
  • patency of large vessels for the treatment of heart attacks;
  • lymph nodes of the chest, which can be seen only with the help of a computer tomograph;
  • injuries of bones, disc herniation, inflammatory and oncological processes.

With prolonged cough, sweating, severe weight loss, general weakness, as well as the appearance of incomprehensible changes on the chest radiograph, it is necessary to contact the doctor for a decision on CT in the thorax. The carried out research will help to exclude lung tumor, their chronic disease, tuberculosis.

Which study is better than CT or MRI?

Today, both diagnostic methods are successfully used for correct diagnosis in many diseases. To understand which type of survey is more effective, you need to know in general terms: what is CT, what is it different from MRT. Both procedures have one similarity - the use of the method of layer-by-layer scanning of the human body. In the rest they are essentially different and do not have common signs in principle of work.

Using MRI, you can better study the condition of such tissues: cartilage, nerves, muscles and ligaments, so this method is especially important in neurosurgery. However, it is practically uninformative for oncological formations of the gallbladder, fractures of bones, ribs, spinal injuries, and cancers in the lungs.

But the use of CT is ideal for the above diseases. The use of a computer tomograph is indispensable in the detection of fresh injuries of the skull, abdominal organs and chest. CT scans have also been successfully used to diagnose strokes at an early stage.

Proceeding from this, it is possible to draw a conclusion: CT and MRI are various diagnostic methods, each of which is important and indispensable for a certain study area.

Is it dangerous for health research on a computer tomograph?

At CT, a person receives a small dose of X-ray irradiation, so the risk of having adverse effects is not greater than with standard radiography. But the refusal of this examination with the existence of medical indications is dangerous for the health and life of the patient due to the lack of timely and reliable diagnosis.

For pregnant women examination on a computer tomograph is contraindicated. However, in extreme situations, for example, with serious injuries, the diagnosis is carried out with a lead apron applied to the abdomen. Breastfeeding is not considered a contraindication for CT.

Where it is better to make a CT scan?

The correctness of the result of computed tomography directly depends on two factors: the professionalism of the radiologist, the quality and technical capabilities of the tomograph itself. Multisection, multislice, multidetector computer tomographs are used for research.All manufacturers of these devices with each new model want to bring the radiation dose to a minimum.

The doctor conducting the study is obliged to know exactly about the aims and subtleties of each survey. Therefore, those who do not know where to do CT can be advised: only in serious diagnostic centers that specialize in the required profile of the disease. They have the latest equipment, which will give a high-quality picture with a minimum of radiation, and a staff of experienced and qualified specialists will help to establish the correct diagnosis.

Cost of computed tomography

During the survey, there are two versions of it: with the use of contrast medium and without it - the price of CT depends on this. The cost of computed tomography also takes into account the research tasks, the amount of work, the area and location of the scanning zone. Also in the price can be included additional services: transfer of results to a disk, duplication of pictures and others. To clarify the price for CT, you can contact the clinic by phone.


So, let's sum up: what is CT and its role in medicine. Computed tomography is a modern and universal method of X-ray examination. Using a computer tomograph, you can examine any organs and parts of the body, evaluate their shape, position, size, structure and condition, and analyze their functionality. The technique with the use of contrast medium makes the survey results more accurate.

Tomographs of the latest models are able to obtain images of the finest layers of tissue (1-5 mm), which makes it possible to successfully use CT to diagnose many serious diseases at an early stage, and to control puncture and biopsy, conservative and surgical treatment. Today, the work of doctors is unthinkable without a computer tomography.