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At least 19 recordsLinked to original sources
PubMed1990

[The use of radiodiagnostic apparatus as human radiation counters in large-scale radiation accidents].

The problem of dosimetry of internal irradiation necessitates the use of human radiation counters (HRC). A state system of radiation safety should be based on a HRC stock in case of large-scale radiation accidents. Radiodiagnostic units can run in the HRC mode therefore they must be considered as an active reserve widely spread throughout the country. Radiodiagnostic devices can be used for control of the thyroid level of 131I and the whole-body content of a mixture of 134Cs and 137Cs.

Accidents↗
PubMed2002

New strategies for the prevention of radiation injury: possible implications for countering radiation hazards of long-term space travel.

New strategies for the prevention of radiation injuries are currently being explored with the ultimate aim of developing globally radioprotective, nontoxic pharmacologics. The prophylactic treatments under review encompass such diverse pharmacologic classes as novel immunomodulators, nutritional antioxidants, and cytokines. An immunomodulator that shows promise is 5-androstenediol (AED), a well-tolerated, long-acting androstene steroid with broad-spectrum radioprotective attributes that include not only protection against acute tissue injury, but also reduced susceptibility to infectious agents, as well as reduced rates of neoplastic transformation. Other potentially useful radioprotectants currently under study include the nutraceutical vitamin E and analogs, a chemically-engineered cytokine, interleukin-1beta, and a sustained-release formulation of an aminothiol, amifostine. Results suggest that a new paradigm is evolving for the prophylaxes of radiation injuries, based on use of newly identified, nontoxic, broad-spectrum prophylactic agents whose protective action may be leveraged by subsequent postexposure use of cytokines with organ-specific reparative functions.

Animals↗
PubMed1976

Counting losses in multidetector radiation counters.

We examined the reasons for the reduction in response of a multidetector radiation counting system when operated at high count-rates and established a convenient method of correction which is accurate to within +/- 1% up to 0-6 X 10(5) counts per second. In its application the method uses the observed count-rates from each detector at the time of measurement and previously determined values of critical time intervals of the electronic system. The detected signals establish these intervals in which further signals occurring within them are lost from the response. These further signals can also cause the loss of the signals establishing the intervals. The correction is of particular value when high-sensitivity whole-body counters are used to measure the activity of administered isotopes in metabolic studies.

Radiometry↗
PubMed1990

[The use of a hybrid scanner as a human radiation counter].

The most promising devices of those for radionuclide diagnosis that can be used for control of nuclides incorporated in the human body during a radiation incident are hybrid scanners. The authors made the calibration of devices of this type to register a mixture of 137Cs and 134Cs. The minimum detected activity was 40 nCi. A methodological error of measurements was +/- 3%. A mathematical criterion for optimization of the geometry of measurements was drawn for devices, including the methodological and statistical components of a total error. This criterion was used for finding optimum sizes of a slot collimator of the device.

Calibration↗
PubMed1997

Monitoring of the biodistribution and biokinetics of dysprosium-165 ferric hydroxide with a shadow-shield whole-body counter.

Radiation synovectomy is indicated when conventional pharmacological treatment of chronic synovitis has proved insufficient. In these cases dysprosium-165 ferric hydroxide (DFH) has been demonstrated to be clinically effective. After application of the agent, blood activity measurements and monitoring of activity distribution by gamma camera imaging over the local lymph nodes and the liver are commonly performed for control of possible leakage. In addition, we have used a shadow-shield whole-body counter with a profile facility to evaluate the biokinetics and biodistribution of 165Dy-DFH. Fifteen intra-articular injections were performed in 13 patients who received a median activity of 6.8 GBq (range 0.5-9.9 GBq) 165Dy-DFH. Activity profiles were obtained with the whole-body counter 2, 4 and 6 h after injection of 165Dy-DFH. The doses to non-target organs were calculated using the software MIRDOSE 3. In 10 of 15 treatments, absence of any leakage could be demonstrated. The effect of scattered rays could be observed in 14 measurements. In three patients small amounts of activity could be detected in the urinary bladder and in three patients activity was detected in the local inguinal lymph nodes, while no leakage could be detected by camera imaging. In these cases the individual doses to the bladder were 15 Gy, 65 mGy and 50 mGy, and those to the lymph nodes, 0.54 Gy, 0.89 Gy and 2.41 Gy. The whole-body counter also enabled the monitoring of activity profiles related to more complex pathological structures. In conclusion, using a whole-body counter activity leakage could be detected with much higher sensitivity than by using a gamma camera. The biodistribution of 165Dy-DFH could be determined, and leakage could be localised and related to organs. These results encourage the use of a whole-body counter to identify the site and extent of activity leakage.

Adult↗