CT scan

Computed Tomography (CT)

The founding fathers of computer tomography are the mathematician Cormac, who theoretically substantiated the possibility of obtaining information and constructing a CT image, and the practice engineer Hounsfield, who implemented the idea in practice. In March 1973, for the first time, a picture of the internal structure of the brain substance was obtained, indicating the location of the lesion focus. This sounds normal now, but 28 years ago, for the first time in the world, mankind had the opportunity to look inside the living brain and to judge violations in it, not for indirect reasons - changing the bones of the skull and brain vessels, but studying the changes in the substrate itself, distinguish between gray and white matter! The idea and its material embodiment conquered the world. And now computer tomographs I, II, III, IV generations have showered on consumers. The last two generations differ from one another in the character of the relationship of detectors receiving X-rays transmitted through the transverse plane of the human body and an X-ray tube rotating around the axis of the patient.

Most modern installations are third-generation devices. And if on the devices of the first generation the process of removing information and getting the "picture" took minutes, on the apparatus of the second - tens of seconds, then on scanners used since the 80s, the account goes for seconds. And the last 8 years, when spiral computer tomographs and electron-beam CT scanners have come into use, we are talking about seconds and their fractions.

So, the diagnosticians were able to look at the object of research in a new, transverse projection, which was earlier accessible only to anatomists. In historical terms, there is a well-known analogue of computed tomography - "pirogov slices" of a frozen corpse, the drawings of which are identical to high-quality CT images.

With the help of this method, questions of neurosurgery and neurology have been successfully addressed. I must say that in the beginning even there were special devices - computer tomographs for the study of the head.

Technical progress led to the improvement of equipment: there were more powerful high-speed devices, adapted for the study of the entire body of the patient. Diagnosis of diseases of the lungs, the abdominal cavity has become the second, the most common area of ​​use of CT.

What is the basis for CT?

On the ability of various organs and tissues (both healthy and pathologically altered) to absorb X-rays. In turn, the attenuation of X-rays is fixed by special sensors, the signal from which is sent to the computer for analysis. As a result of complex mathematical calculations, the spatial relationship of points with different ability to absorb X-ray radiation can be represented in the form of mathematical tables, graphs, and even more graphically in the form of a graphic "picture." The more information is used, the higher the quality.

The picture obtained as a result of the CT scan is absolutely objective, it can be evaluated and studied on the instrument monitor, fixed on paper or X-ray film, and compared and compared for a period of time if there is a complex diagnostic case.

Every new discovery in physics or technology inevitably finds its embodiment in medicine; A vivid example of this can be the discovery of Roentgen and its brilliant introduction into medical practice. Computer tomography (CT) can be considered as a new stage in the development of roentgenology, in turn, the principles of mathematical processing in the construction of images in CT forms the basis of the non-radiotherapy method - magnetic resonance imaging.

Computer technologies have stepped so far that now the subject of the diagnostic process is the so-called "virtual" endoscopy, in which it is possible to move within the reconstructed object, which is especially important in the study of the areas of the intestine, bronchi, ducts behind pathological constriction, which can not be passed to the real endoscope, But "virtual" under the force.