SU461687A1 - Composition for obtaining tissue equivalent material - Google Patents

Description

1. Equality of electronic densities of tissue material and human tissue.

2.Effective atomic number by photoelectric absorption

ultrasound, 4j ultras, 4

  e / -A; - / g

tissue-equivalent material and human tissue to be equal to each other, while

 L OL-2 /

to,

noAi

where Zi is the atomic number i-ro of the chemical element included in the material;

Arg is the mass number of the gth chemical

. an item;

Pi-weighted dale of this element; Po and NO are the electron density of the material and Avagadro number, respectively.

3. Equality of effective atomic numbers by coherent scattering

71.5 f yl, 5

 - Li

human tissue and tissue equivalent material.

The main parameters of the tissue-equivalent material obtained on the basis of the composition according to the invention, but compared with the parameters of human muscle tissue are given in table. one.

Table 1

The stability of the tissue equivalence characteristics over time was checked for 4 years by comparing the relative measurements of the intensity of soft x-ray and -radiation passing through a sample of tissue-equivalent material of known thickness under identical geometric conditions, as well as comparing the values of the calibration coefficients of detectors obtained using tissue equivalent phantom, in identical geometrical conditions, but at different times. A disc with a diameter of 10 cm and a thickness of 5 mm was used as a sample of tissue equivalent material. The intensity of soft X-rays and γ rays in the photon energy range of 13–60 keV passed through the samples was measured under the conditions of a narrow beam geometry using spectrometric radiation sources (plutonium 239 and americium 241).

The magnitude of the intensity of the detecting radiation was determined by the area under the photo-picks on the spectrograms in the energy boundaries of 10-25 keV and 35-84 keV.

A flow proportional counter with argon-methane filling, a Nal (Te) thin crystal scintillation block and a multichannel amplitude analyzer were used as detection and recording equipment.

The test results are shown in Table. 2 (the intensity of the radiation transmitted through the layer of tissue-equivalent material is given in relative units)

table 2

The stability of the properties of the tissue equivalent material based on the composition of the invention over time is also indirectly confirmed by phantom measurements taken over a four year period.

Claims (1)

Invention Formula The composition for obtaining tissue-equivalent material, characterized in that in order to expand the energy range of tissue-equivalence of the material to the low photon energy, to obtain a material with good structural properties, stable in time, it consists of the following components, taken in a ratio, weight. including: Polymethyl methacrylate2 Methyl methacrylate 0.8-1.5 Dimethylparatholuidin 1.7-10-2-3.3.10-2 Benzoyl peroxide1, 5-10-2-3.0.10-2 NaaSaOs2,8.10-2-4,7.10-2