Biomedical subjects

E N Simonov

Publications and source records attributed to E N Simonov.

4 recordsLinked to original sources

PubMedDate not supplied

[Physical problems in the medical X-ray computer tomography].

Physical models related with solution approximation of a transport equation applicable to X-ray computer tomography are under discussion. Use of a point mono-energy collimated irradiation source is defined; when such source interacts with an investigated object, the effect of scattering of primary photons can be neglected or considered for the general tendency of rectilinear propagation of photons in a substance. The model can be adopted for photon energies ranging from 20 to 150 keV, in which a weak effect from Compton scattering and photoeffect predominance are evident.

Health Physics↗

PubMedDate not supplied

[A classification of tomography examination methods].

An analysis of current tomography evolution was performed making it possible to classify the tomography tools of object examinations by projections. It was based on a position of radiation source, its type and reconstructed position in its interaction with a studied object. Significance of X-ray computer tomography within the above classification was defined.

Humans↗

PubMedDate not supplied

[Limiting resolution of X-ray computer tomography in examination of man].

It is shown as necessary to increase the intensity of radiation source by at least 20 times in order to ensure a 2-fold enhancement of resolution. It predetermines the permissible values of dose per object, which in their turn, condition the permissible values of quantum noise per image (tomogram) as well space and density resolutions. The dose, when intensified purposefully in order to enhance the tomography image resolution, is apparently a limitation for examination of man by X-ray computer tomography.

Humans↗

PubMedDate not supplied

[The study of the possible use of image reconstruction algorithms based on integral radon changes in small-angle X-ray computer tomography].

Described are the results of a study of how a quantity of aspect angles affects the computer algorithm (deprojection with convolution filtration _ DCF) as well as of how symmetry and asymmetry in the aspect-angle position affect the space- and density resolutions of tomographic images. Examinations were made by using the reconstruction algorithm model (DCF) with fan X-ray geometry.

Algorithms↗