[Analysis of factors affecting the results of estimation of the detective quantum efficiency of digital X-ray detectors within high and low spatial frequency ranges].

Factors affecting the results of estimation of the detective quantum efficiency of digital X-ray detectors within high and low spatial frequency ranges are studied. These factors include energy dispersion and loss in the conversion channel, nonuniformity of the X-ray detector irradiation field, and the internal noise of the system.

[Hardware-software system for monitoring parameters and characteristics of X-ray computer tomographs under operation conditions].

The results of testing of hardware and software for monitoring parameters (mean number of CT units, noise, field uniformity, high-contrast spatial resolution, layer width, dose) and characteristics (modulation transfer function) of X-ray computer tomographs are presented. The developed hardware and software are used to monitor the stability of X-ray computer tomograph parameters under operation conditions.

[Experimental and computational evaluation of quality of digital X-ray imaging].

The results of the use of specialized software for experimental and computational evaluation of the characteristics of digital X-ray detectors are analyzed.

[Analysis of frequency-contrast characteristics of digital X-ray image detectors].

The effect of various computing procedures on the results of estimation of parameters used for MTF calculation is analyzed. Experimentally evaluated modulation transfer functions of some types of digital X-ray image detectors are presented.

[Experience in the use of a test phantom for checking the biopsy needle position in stereotactic mammography].

The possibility of the use of a special test phantom for checking the biopsy needle positioning accuracy in mammographic stereotactic devices is discussed. The test phantom meets the requirements of the state standard GOST R50267.45.

[Correlation of noises in the channels of digital X-ray receiver-transformer and the evaluation of registration's quant efficiency]. / Vliianie korreliatsii shumov v kanalakh tsifrovogo rentgenovskogo priemnika-preobrazpvatelia na otsenku kvantovoi effektivnosti registratsii.

Theoretical and experimental research results related with the influence of correlation of signals in neighboring elements of digital X-ray receiver-transformer produced on the evaluation of the output ratio noise/signal and, as a consequence, on the evaluation of quantum registration efficiency are described in the paper.

[The results of the monitoring of characteristics of digital receivers for X-ray images by using enterprise (VNIIMT) reference standard 01-22-04]. / Resul'taty aprobatsii metodik kontrolia kharakteristik tsifrovykh priemnikov rentgenovskogo izobrazheniia pri ispol'zovanii standarta predpriiatia (VNIIMT) 01-22-04.

Described are the results of testing of methods of the new 01-22-04 standard designed for monitoring the image-quality parameters of digital X-ray converter-receivers (made alongside with tests of digital X-ray diagnostic units ProScan-7000 and ProScan-2000).

[An experience in using a formalized protocol in describing digital fluorograms]. / Opyt ispol'zovaniia formalizovannogo protokola dlia opisaniia tsifrovykh fliuorogramm.

The case study deals with designing the formalized flow for digital photofluorogram and with results of their clinical testing. Recommendations are defined for improving the protocol program.

[Specific features of monitoring the characteristics of digital X-ray diagnostic systems]. / Osobennosti kontrolia kharakteristik tsifrovykh rentgenodiagnosticheskikh sistem.

The paper analyzes the specific features of monitoring the basic characteristics of formation of images in the digital X-ray diagnostic systems and considers the potentialities of transfer from traditional expert assessments to more objective and precise experimentally calculated methods.

[Methods of assessing the parameter detail-contrast of X-ray converting receivers]. / Metody otsenki parametra detal'-kontrast priemnikov-preobrazovatelei rentgenovskogo izlucheniia.

The paper analyzes methods for assessing the quality of an image in X-ray complexes (emphasis being laid on digital systems) by using the test object detail-contrast. Two possible variants of design of the test object are presented. Data of experimental assessment and comparison of the parameter detail-contrast for number of X-radiation converting receivers are given.

[Test object for controlling the quality of orthopantomography]. / Test-ob"ekt dlia kontrolia kachestva ortopantomografov.

Great emphasis is placed on a FO-01 orthopantomographic phantom test for checking the position of the projection boundary of an isolated layer, its shape and thickness. The basic specific feature of the phantom test is that one can rather simply check the adjustment of orthopantomographs of different kinds (including digital ones) and make their comparative assessment by the projection of an isolated layer with certain resolution. Examples of projection nomograms of an isolated layer for different orthopantomographs, which are obtained by this test object are given.

[Methods of automatic control of the characteristics of digital X-ray detectors]. / Metody avtomatizirovannogo kontrolia kharakteristik tsifrovykh rentgenovskikh detektorov.

Great emphasis is laid on automatic control of the most important parameters of X-ray image, such as contrast sensitivity and dynamic range, in the digital X-ray apparatuses that have recently found a wide clinical application in Russia and foreign countries. Methods and softwares are proposed for exercising this control.

[Definition of quantum efficiency of X-ray detectors]. / K opredeleniiu kvantovoi éffektivnosti detektorov rentgenovskogo izlucheniia.

Different definitions available in the literature on the quantum efficiency of X-ray detectors are presented and compared. The relationship of this parameter to spatial frequencies for quantum accounting receivers and energy accumulating ones is analyzed. A procedure is proposed for evaluating the quantum efficiency of the detectors in the area of zero spatial frequencies, which is rather simple and requires no special testing equipment.