ABSTRACT
Doses for a range of examinations and views using digital X-ray equipment with full-body linear slit scanning capabilities (Statscan) have been compared with those from other published studies. Entrance doses (free-in-air) were measured using a dosimeter, and effective doses were generated using a Monte Carlo simulator. Doses delivered by the linear slit scanning system were significantly lower than those from conventional X-ray equipment. Effective doses were between 9 and 75% of the United Nations Scientific Committee Report on the Effects of Ionising Radiation doses for standard examinations. This dose reduction can be explained by the properties of linear slit scanning technology, including low scatter, beam geometry, the use of a digital detector and the use of higher than usual tube voltages.
Subject(s)
Radiation Monitoring/methods , Radiometry/methods , Whole Body Imaging/instrumentation , X-Ray Intensifying Screens , Air , Algorithms , Equipment Design , Humans , Monte Carlo Method , Radiation Protection/instrumentation , Radiation Protection/methods , Radiation, Ionizing , Radiographic Image Enhancement/instrumentation , Radiography/methods , Whole Body Imaging/methods , X-RaysABSTRACT
The genetically significant dose was initially defined by UNSCEAR in 1958. The National Radiological Protection Board (NRPB) derived a formula from this definition as shown in the NRPB Report, NRPB-R106. It combines the frequency of radiological examinations obtained during the country-wide survey and estimates of gonadal doses for different examination types, together with population and child expectancy data. The task was set to find a model in order to draw the best representative sample of the population, and it was determined in a unique way, namely the so-called Dollar Unit Sampling method. A sample of 27 institutions out of a possible 292 (9%) was drawn. The GSD for the total South African population was calculated, using the above-mentioned formula, as 95 microGy. The breakdown of the genetically significant dose for the various South African race groups was Asian--229 microGy; black--67 microGy; people of color (mixed race)--112 microGy; and white--463 microGy.
Subject(s)
Genitalia/radiation effects , Radiation Dosage , Radiation Injuries/epidemiology , Radiography/statistics & numerical data , Age Factors , Data Collection , Dose-Response Relationship, Radiation , Female , Humans , Male , Racial Groups , Sex Factors , South AfricaABSTRACT
Commerically available collimators are not suitable for the visual demonstration of the kinetics of 59Fe, because of its physical properties. A locally designed collimator, that provides integral visual information of the whole body distribution of erythropoietic marrow, is discussed. Wholebody scans of 4 individuals are also included to demonstrate the capabilities of the collimator.
