[en] Indexes of organ doses for a standard-size patient for commonly performed examinations are computed based on measurements of exposure and beam size using a specially designed test stand. This provides a method for observing the wide range of technique factors and thus the exposures and doses employed by operators of X-ray machines. Using these data, participating agencies are able to set program priorities, mount action programs to improve technique and evaluate the impact of these programs. The system design, instruction manuals, computer programs and specifications for the test stand are available to any agency interested in considering the applicability of the NEXT organ dose index system to its X-ray control program

[en] The use of fast neutrons in the treatment of cancer necessitates a knowledge of the normal tissue responses. This study was designed to compare the late effects of fractionated doses of fast neutrons with fractionated doses of photons on canine brains by evoked response recording and viewing computerized tomograms (CT). A relative biological effectiveness (RBE) of 4 was obtained for normal brain tissue assessed by mortality and onset of neurologic symptoms. Every three months post-irradiation, visual and sensory evoked responses were recorded. Changes over time appeared to be minimal; however, computerized tomographs showed marked brain shrinkage. A method of quantitating cerebrospinal fluid and parenchymal volumes from scans is described and future use of these CT ratios to generate dose response curves and RBE values is postulated

[en] A description is presented of a model being used in the USA to determine the genetically significant dose to the population as a consequence of radiodiagnostic procedures

[en] A 10-12 bit gray scale is provided in commercial laser film digitizers. The true contrast resolution on the digitized image within 200 microns square is limited by both the quantum mottle and instrumentation noise. In this paper, the authors investigate that mean value, standard deviation, and adjacent pixel correlation coefficient on a calibrated step wedge film with two laser digitizers. The results were disappointing. On the output side, the brightness of different grey levels from a clinical monitor was measured with a narrow angle luminance probe. In addition, the implications for teleradiology applications are discussed in this paper