No abstract available

[en] The experiences are described of the examination of orbita in children using computer tomography (CT). Over a period of four years 42 examinations were performed of children in the age ranging between 7 months and 15 years, i.e., 2.7 per cent of all CT examinations performed. The highest diagnostic yield was in orbita tumours. The possibilities of CT are demonstrated on examples. (author)

[en] Computer tomography was used in 42 patients for the exploration of ventricular and subarachnoidal spaces following intraventricular, lumbar or suboccipital injections of 3 to 5 ml Amipaque using the kind of manoeuvre to permit optimum filling of the region concerned. This type of CT ventriculo- or cisternography is a significant supplement to plain CT examination particularly because it supplies data on the causes of CSF passage blocks. Thus, in two female patients it proved possible to localize cysts in the 3rd ventricle, the density of which was no different from that of CSF. As regards benign stenoses of the aqueduct, it is likely to yield less information than conventional specific ventriculography. On the other hand, the technique gives perfect visualization of all possible communications between pathological intracranial cavities and the ventricular system. CT cisternography proved useful for the identification of small-size isodense growths in the region of the sella turcica, and brought convincing evidence of the causes of profuse liquorrhea by demonstrating the presence of nasal meningocele. It was also found helpful in the analysis of the craniocervical region, otherwise difficult to survey. (author)

[en] The article deals with the development of radiation protection at the Dukovany NPP and its results during the 15 years of operation. The monitoring procedures and methods are described and the new radiation protection trends which are being introduced at Dukovany are outlined. The collective effective dose at Dukovany is compared with the values determined at other nuclear power plants. (author)

No abstract available

[en] Conventional instrumental neutron activation analysis (INAA) was used to determine selenium concentrations in the kidneys of 20-day-old and 86-day-old male and female rats. The females exhibited a more pronounced increase in kidney selenium concentration during maturation. Adult rats evinced a sex-dependent difference in kidney selenium concentration. Kidney selenium concentrations were also determined in male rats subjected, in the early post-natal period, to interventions that were known to affect the toxicity or metabolism of selenium compounds. The content of selenium in the laboratory diet was determined for each experiment by a multiparameter analysis which eliminated the effect of spurious energy interferences on the determination of low selenium concentrations by INAA. Flame atomic absorption spectrophotometry was employed as a reference method for the assay of low selenium levels. (author)

[en] Recently, high resolution micro-radiography became of great interest. Very thin scintillator layers of about 5–20 micrometres are used to achieve spatial resolution below one micrometre in application for low energy X-ray micro-radiography [1]. Such thin screens are mainly used in micro-XCT and nano-XCT systems (X-ray Computed Tomography) with either micro-focus X-ray tubes or with synchrotron sources [2]. This work deals with a high-resolution CCD camera together with different optical systems and different single crystal scintillators in application for low energy X-ray micro-radiography. The light distribution on the screen is re-imaged by an optical system (usually represented by classical microscope objective together with a field lens) to a high-resolution CCD or CMOS chip. A theoretical modelling and practical comparison of a camera set-up has been done to investigate the system resolution limits. Thin screens were prepared from YAG:Ce scintillator. The resolution is presented on test patterns. As recent optical systems are limited to the classical microscopy objectives only, we further investigate a possibility to develop a custom-made objective fully dedicated to X-ray imaging application.