Today, almost everyone has heard about computed tomography, due to its popularity. But for those to whom it is assigned, it is important to know in detail: what is CT and the principle of its action.
General information
Computed tomography (CT) is a modern layered study of the human body. It is based on computer measurement and processing of the difference in the attenuation of x-ray radiation by tissues of different density. Using computed tomography, the organ under investigation is visible from different angles, so you can get its image in all projections and in three-dimensional form.
For CT, a special X-ray computer tomograph is used. It includes a movable table, which enters with the patient into the hole of the scanning unit, in which there are radiation sensors and an x-ray tube.
X-rays pass through the studied organ of a person, radiation becomes weaker when passing through tissues. Rotating at an angle of 360 degrees around the patient, the x-ray emitter scans a portion of his body from different angles. At this time, sensors located on the other side of the patient are engaged in the conversion of radiation energy into electrical pulses. Then they undergo computer processing, the result of which is visible on the monitor. The resulting images are studied and analyzed by a radiologist, then they are recorded on a
storage medium and printed on film. The entire research process takes no more than 10 minutes, but depending on the tomograph and the specifics of the diagnosed zone, it may take up to half an hour.
Recommendations before and after the examination
Patients who have been prescribed computed tomography want to know: what is a CT scan, what recommendations should be followed before the procedure, during and after it. For all types of scanning, it is recommended to refuse food and drink 2 hours before the study.
For the diagnosis of certain organs, and in some cases, by the decision of a doctor, intravenous administration of a contrast medium is required to improve the results of the study. Each patient will be warned about this by the attending doctor or medical staff of the CT room.
It is important to know that if a patient has electrical, mechanical and magnetic implants (prostheses, metal plates, pacemakers), the day before the CT scan there were studies using barium suspension, and also during pregnancy it is necessary to inform the doctor about this.
The investigated part of the body should be without clothes and jewelry. During the examination, for the reliability of the result, you need to lie still, you may need to hold your breath for several seconds. Computed tomography is an absolutely painless examination.
After a CT scan with intravenous administration of the drug, it is necessary to take up to 2 liters of water within two hours to get it out of the body as soon as possible.
What are the indications for the use of CT?
Computed tomography is used in a planned manner, emergency cases, medical and 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 also to exclude oncological formations.
In an emergency, the study is carried out in case of serious injuries, suspicions of life-threatening damage to organs, blood vessels, diagnosis of cerebral hemorrhage.
When do abdominal CT scans do?
Computed tomography of the abdominal space is used to accurately diagnose diseases of the spleen, gall bladder, liver, pancreas, stomach, then
the intestines.
CT scan of the abdominal cavity is mainly carried out with intravenous administration of a contrast medium, since the soft tissues of organs are difficult to diagnose. Contrast, which tends to accumulate unequally in various tissues, makes it possible to distinguish organs from each other, which favors an accurate diagnosis.
Symptoms in which doctors recommend an abdominal CT scan: frequent pain in the abdomen, yellowing of the skin and sclera, anemia, sudden weight loss, the formation of an incomprehensible nature, identified by ultrasound.
When is spinal tomography performed?
This study is widely used to diagnose diseases of the thoracic, cervical and lumbar spine. It makes it possible to simultaneously evaluate the structure of bones, blood vessels and soft tissues and obtain a three-dimensional image.
CT of the spine is carried out in such cases:
- any spinal injury;
- diagnosis of congenital malformations;
- diseases of the spinal cord of an infectious nature;
- arthritis, osteoporosis;
- study of the causes of pain (change in the spine, disc herniation );
- tumors or metastases from neighboring organs.
You should be aware that even after an insignificant at first glance injury in the spine, as well as any lower back pain that radiates to one of the lower extremities, it is urgent to consult a doctor. Only the doctor after examining the patient can decide on the need for computed tomography.
What are the indications for computed tomography of the chest?
A computer tomograph has been successfully used to diagnose diseases of the cardiovascular system, bones and ribs of the thoracic spine, and to assess the condition of the lungs. CT of the chest is necessary in the diagnosis of:
- tuberculosis
- heart conditions (presence of tumors, cysts, wall thickness);
- patency of large vessels for the treatment of heart attacks;
- lymph nodes of the chest, which can only be seen with a CT scan;
- bone injuries, disc herniation, inflammatory and oncological processes.
With prolonged coughing, sweating, sudden weight loss, general weakness, as well as the appearance of incomprehensible changes in the chest radiograph, it is imperative to consult a doctor for a decision on CT in the chest area. The study will help to exclude a tumor of the lungs, their chronic disease, tuberculosis.
Which study is better than CT or MRI?
Today, both diagnostic methods are successfully used to correctly diagnose many diseases. To understand what type of examination is more effective, you need to know in general terms: what is a CT scan, how does it differ from MRI. Both procedures have one similarity - the use of the method of layer-by-layer scanning of the human body. Otherwise, they differ significantly and do not have common features in the principle of operation.
With the help of MRI, it is possible to better study the state of such tissues: cartilage, nerves, muscles and ligaments, therefore this method is especially important in neurosurgery. However, it is practically uninformative with 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 detecting fresh injuries of the skull, organs of the abdominal region and chest. CT is also successfully used to diagnose strokes in the early stages.
Based on this, we can conclude: CT and MRI are different diagnostic methods, each of which is important and indispensable for a particular research area.
Is a CT scan dangerous to health?
With CT, a person receives a small dose of x-ray exposure, so the risk of adverse effects is not greater than with standard radiography. But the rejection of this examination in the presence 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, a CT scan is contraindicated. However, in extreme situations, for example, with serious injuries, the diagnosis is carried out with the application of a lead apron on the stomach. Breastfeeding is not considered a contraindication for CT.
Where is the best 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. For research, multislice, multispiral, multidetector computed tomographs are used.
All manufacturers of these devices with each new model want to reduce the radiation dose to a minimum.
The doctor conducting the study must know exactly about the goals and subtleties of each examination. Therefore, those who do not know where to do a CT scan can be advised: only in serious diagnostic centers specializing in the required profile of the disease. They have the latest equipment that will give a high-quality image with a minimum of exposure, and a staff of experienced and qualified specialists will help to make the correct diagnosis.
Cost of computed tomography
During the examination, there are two options: 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 objectives of the study, the amount of work, the area and location of the scan area. Also, the price may include additional services: transferring results to disk, duplicate images, and others. You can clarify the price of CT by contacting the selected clinic by phone.
Conclusion
So, to summarize: 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 a contrast agent makes the survey results more accurate.
Tomographs of the latest models are able to obtain images of the thinnest layers of tissue (1-5 mm), which makes it possible to use CT scans both for the diagnosis of many serious diseases at an early stage and for the control of punctures and biopsies, conservative and surgical treatment. Today, the work of doctors is already inconceivable without computed tomography.