Antimicrobial x-ray contrast articles]

A procedure has been developed to prepare the radio-opaque polymer composition containing an antimicrobial substance that can be used in medicine. The findings of the antimicrobial activity of products made of the above composition are presented in the paper.     

The resolving capacity of systems for the reproduction of x-ray images

At digital and film X-ray studies, the geometry of a survey exerts a varying effect on the system's resolution. This may lead to the better quality of digital X-ray image when actual magnification is performed.     

Control of effective doses in x-ray studies]

Developing the controlling techniques for dose loads in patients has led to the introduction of methods for evaluating the new dosimetric value an effective dose. When it is determined, regular refinement of calculating multiples causes errors as hundredths of a percent. Therefore, in addition to tabulated techniques of evaluating the effective dose and direct measurement of the dose absorbed per radiation area, one can determine midpoint exposure of an X-ray feeding device and use a translating program implemented in the Indor-C indicating device designed by the authors. In going from 60 kW to 120 kW, changes in the superficial dose by 15-50%, the absorbed dose by 10-45%, the 5-cm depth dose by 3-5 times can be neglected.     

The measurement of the dynamic range of digital systems for visualizing x-ray images

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).     

Development of a system controlling x-ray diagnostic devices]

The purpose and criteria for efficiency (errors of anode voltage holding, tube current, and exposure) of the system controlling X-ray diagnostic devices are considered from theoretical and practical points of view. A microprocessor-controlled variant of the controlling system developed for numerous existing six-pulsed generators of the -3 type is outlined. The design and operation of the key circuit diagram of X-ray tube filament in the PEHA 50-6 microprocessor-controlled feeding device are shown in detail.     

Reconstruction of images in emission tomography]

The algorithm of back projection with filtration for exponential Radon transform leads to strong distortion for big diameter objects. The main reason for this distortion is mainly the exponential increase of errors in the quadrature formula for a weighed back projection operator. So it is sometimes more convenient to use the back Radon transform R-1 and then to correct the result, taking into account attenuation. For this purpose, the approximation formulas are given, which connect f and R-1 R mu f. An appropriate iteration reconstruction algorithm is also considered. Application exponential Radon identities for projection data analysis are also discussed.     

Improvement of optic characteristics of the x-ray protective glass]

The optic characteristics of the roentgen protection glass (RPG) are shown to be capable of being improved through application of a translucent coating onto its working surface. This eliminates losses due to reflection from the RPG of a luminous flux proceeding to the examiner from the fluorescent screen of the X-ray apparatus. The proposed improvement of optic characteristics of the RPG will make it possible to cut down by 15 per cent the dose rate of ionizing radiation to which both the patient and the physician are exposed during roentgenoscopy.     

Device-aided determination of an effective dose in x-ray studies]

The paper proposes how to determine an effective radiation dose for patients undergone X-ray examinations, which includes the estimation of the size of a field while measuring the superficial dose and the assessment of an experiment protocol by taking into account the X-ray receiver used to measure exposure.