Human he alth is currently exposed to a variety of dangers. To prevent serious diseases that can even lead to death, examinations should be carried out. Computed tomography is one of the methods actively used for these purposes. CT machines come in many varieties.
General description of the procedure
It's worth starting right away with the fact that computed tomography belongs to the group of non-invasive examination methods. This procedure involves the diagnosis of the internal parts of the human body in layers. The essence of the method lies in the fact that the CT machine emits X-rays that can pass through anatomical obstacles of various densities.
The absorption of such rays takes place with different intensity, which depends on the density of the area under study. To date, computed tomography is one of the most effective methods of examination, allowing to detect a variety of diseases at different stages.
What is the equipment
What the device looks likeCT, which allows such examinations? The device is presented in the form of a rectangular box, which has a hole in the center in the form of a tunnel. The object under study, that is, a person, lies down on a special retractable table passing through this tunnel. For examination, the device has a group of special sensors and a narrow rotating beam of radiation. The sensors are placed on a scanned ring called a gantry.
In addition, the CT device has a set of instruments responsible for the formation and output of the image. Most often, this complex is located in the next room. Here the specialist controls the operation of the scanner and receives information about the progress of the examination.
Sequential and spiral units
Today, all CT devices are divided into two groups - sequential and spiral.
It is worth considering them in more detail with sequential ones, since they were an earlier generation of equipment used for computed tomography. Such equipment made it possible to construct only one section during the examination, which was the result of X-rays. To date, such devices are used extremely rarely, since the procedure takes too much time. In addition, such CT machines are characterized by too high radiation exposure.
The second type of spiral-type devices made it possible to obtain more information in a shorter period, the amount of radiation affecting a person wasreduced. These advantages were achieved precisely due to the helical effect of radiation due to the mixing of the directions of the scanned tube.
That is, today, if you choose which CT machine is better, then you can indisputably say that spiral and multislice with the number of layers from 8 to 64. We will discuss them below.
Subspecies of spiral devices
Modern medicine uses single or multi-slice devices. Single-slice devices form only one scanning layer in one full circle. Multi-slices form several slices at once in one circle.
There are several significant advantages of multispiral computed tomography devices: the examination speed is much higher, reduced ionizing effect on the examined person, increased area of anatomical examination, improved image quality.
What CT machine is currently being used? The development of technology has made it possible to create equipment with the ability to scan a huge number of layers. Thus, advanced CT units can create from 16 to 64 layers. These machines are the most common. If we talk about their characteristics, then, for example, 16-slice equipment has speed parameters that are 24 times higher than single-slice equipment or, say, 4 times higher than 4-slice equipment. The time spent on scanning is also significantly reduced (by about 30 times). Due to reduced exposurethe dose of CT rays also drops significantly.
In order to significantly improve the quality of the resulting image and increase its resolution, as well as to further reduce the time spent on diagnostics, units with a number of slices of 64 were introduced into medicine.
Purpose of 64-slice devices
The use of such complex aggregates is essential when top quality tomography is required. A huge number of sections will allow you to examine all parts of the human body. The most important detail - a large number of layers will allow you to qualitatively check the areas that are constantly in dynamics. These include the heart and bone joints. Due to the rapid imaging of these units, they have been able to replace classical examination methods such as angiography and insertion of cardiac catheters.
Modern equipment allowed for a few seconds to examine the coronary vessels, abdomen, lower pelvis and chest. Modern tomography equipment has the possibility of contrast enhancement. It allows you to highlight in the picture the smallest details of the vascular system of the brain, kidneys, tumor formations, violations of the integrity of bones and other injuries, ailments.
Today, rarely, but still there are units with a 320-slice mode of operation. The capabilities of such devices are at an unimaginable level.
Closed and open typetomograph
From a constructive point of view, all devices for tomography can be divided into two types - closed and open. If we talk about the first type, then in this case the equipment will have a tunnel form of a closed type. Inside it, the object under study, that is, a person, will be placed. However, it also happens that people suffer from claustrophobia or for other reasons are afraid, or cannot be examined on this type of unit. In such cases, open CT is used.
This apparatus emits X-rays in a spiral, and there is no closed tunnel in the design.
CT or MRI?
As it has already become clear, computed tomography is a method of examination using x-rays. However, the use of modern equipment allows you to get a three-dimensional image, not a two-dimensional one.
MRI or magnetic resonance imaging is a procedure that also allows you to get volumetric results of the study. The main difference between the two methods is that MRI uses electromagnetic waves rather than x-rays.
CT and MRI machines, despite their similarity, are used in different cases. Examination on CT equipment is more often prescribed in case of serious injuries, for example, a fracture of the metatarsus, wrist, etc. It can be used to detect bleeding, examine the lungs.
MRI can give more information when examining tumors, you can conduct a detailed study of the human nervous system, identify cysts, inflammatoryprocesses, hernias.
Thus, it can be concluded that the difference in the type of radiation is the key between CT and MRI machines.
PET-CT examination
Today, another type of examination is used, which is called positron emission tomography or PET-CT. In this case, we are talking about tomography using radionuclide preparations.
If we talk about the PET-CT machine, then its work is quite similar to the work of a conventional tomograph. The design is a large ring with installed sensors that respond to radiation. Instead of a tunnel hole, PET-CT has a couch that slides inward. The impact of this equipment is based on the work of positron emission. If we talk about the radiation dose, then it will not exceed that which a person will receive during the passage of a conventional computed tomography.
What are the benefits of the PET-CT procedure
Of the main advantages of such a procedure and equipment, it is worth highlighting the following: almost 100% accuracy of the study, completely painless, can only detect emerging ailments, no side effects on the human body.
In the end, it is worth noting that this examination procedure itself is new. It allows you to easily assess the performance and condition of the internal organs of a person.
The price of a CT machine depends on the number of scanned layers, on the year of manufacture. For example,A 32-slice device from Toshiba costs about 17,000,000 rubles.
