[Specific features of design of digital X-ray diagnostic apparatuses on the basis of CCD matrices].

Specific features of modern digital screen-optics-CCD-matrix systems are considered. Characteristics of single- and multi-matrix systems are analyzed. It is shown that all disadvantages of single-matrix systems as compared to multi-matrix systems can be eliminated using modem high-efficiency CCD matrices.

[Optimization of dynamic fuzziness and enhancement of image quality of an URI/230-Amethyst digital image intensifier]. / Optimizatsiia dinamicheskoi nerezkosti i povyshenie kachestva izobrazheniia tsifrovogo usilitelia rentgenovskogo izobrazheniia URI/230-"Ametist."

In X-ray diagnostic units, digital image intensifiers with a SSD matrix have recently been used instead of vacuum vidicons. Along with the well-known advantage of SSD matrixes, they fail to reach the capacities of vidicons in transmitting movable images. The authors consider that the way out of this situation is to use recursive filters and arithmetic logic devices. The automatically used filters are particularly original.

[The measurement of the dynamic range of digital systems for visualizing x-ray images]. / Izmerenie dinamicheskogo diapazona tsifrovykh sistem vizualizatsii rentgenovskikh izobrazhenii.

The paper presents a procedure to measure the dynamic range of digital X-ray image visualization systems, which is used for acceptance and certification tests of this class of equipment. The procedure is based on the use of experimental dependences of transmission of a narrow X-ray beam on the thickness of an aluminium or copper absorber (filter).

[The characteristics of digital electron optical systems for x-ray diagnosis]. / Osobennosti tsifrovykh élektronno-opticheskikh sistem dlia rentgenodiagnostiki.

The paper deals with the specific features of X-ray diagnostic units that have no screen-filming device for film X-ray study, with the requirements for hardware and software of these units. It gives data on specific systems for digital X-ray study.

[New types of multi-size cameras]. / Novye tipy mul'tiformatnykh kamer.

The paper provides a technical evaluation of the thermographic multi-sized chambers and recorders used in them, which have appeared on the market. It compares the control images obtained by employing thermographic and conventional multi-sized chambers.

[Low-dose digital radiography in diagnosis of stomach and duodenal cancer and peptic ulcer]. / Malodozovaia tsifrovaia rentgenologiia v diagnostike raka i iazvennoi bolezni zheludka i dvenadtsatipestnoi kishki.

While analyzing data of 149 studies of the stomach and duodenum, covering patients with gastric cancer (n = 66), peptic ulcer (n = 41) versus 42 individuals without abnormalities by means of a STs3 digital device, the authors express their opinion on some aspects of the gastroenterological application of digital roentgenology. To evaluate the potentialities of recording all details, revealed changes on the standard writing paper by digital roentgenology is a main area of the study. For this, the data of the 149 studies were used to compare the informative value of the obtained image on the X-ray film and writing paper. In the author's opinion, digital roentgenology completely rules out the application of an X-ray film, by replacing it by standard writing paper.

[Use of digital technology in x-ray television imaging]. / Primenenie tsifrovoi tekhniki pri rentgenotelevizionnom prosvechivanii.

The questions of decreasing radiation loads in X-ray TV units due to application of digital means of storing X-ray TV images are considered. On the basis of the theoretical analysis of the spatial frequency, time and noise parameters of the X-ray image amplifiers the authors derived expressions relating the input ratio signal/noise of the USSR manufactured URI to the intensity of the X-ray radiation dose of the transformer input. It was established that under the pulse mode of the X-ray unit and storage in the digital memory of the TV unit signal to get the needed ratio signal/noise of the output videosignal (37 dB) it is quite enough to secure on the transformer input the value of the X-ray radiation dose of 15 microR. The functional scheme of the digital unit operating in pulse and pseudodynamic modes of X-ray diagnostic units is outlined.

[Bi-dimensional correction of x-ray images]. / Dvumernaia korrektsilia rentgenovskikh izobrazhenii

The frequency and contrast characteristics of the unit of the shadow image formation point to a material weakening of the high-frequency components in the spectrum of spatial frequencies already during the formation of the X-ray image. To compensate for this weakening that also takes place in other subassemblies of the television X-ray installation the introduction of an aperture corrector is necessary. As such a corrector in transmitting an image of little mobile objects a bidimensional aperture corrector set up on the transmitting television tube can be effectively used.