Introduction: High kVp techniques, 15% or 10-kVp rules, are well-known dose reduction methods. Traditionally, the use of high tube potential (i.e. increased kVp) is associated with decreased radiographic contrast and overall image quality. Recent studies suggest contrast and image quality are not heavily reliant on kVp with digital systems. This study aims to assess the effects of the high tube potential technique on clinical radiographic image quality when using digital systems, to validate high kVp as a dose saving technique. Methods: A selection of comparable pelvis and lumbar spine radiographs were collected from the hospital's picture archiving and communication system (PACS), with technical factors recorded. All clinical radiographs were assessed by 5 senior radiographers using a 15-point visual grading analysis (VGA) rubric. Results: For 40 AP pelvis radiographs and 40 lateral lumbar spine radiographs, reduction in the dose area product (DAP) with higher kVp is seen. Average pelvis DAP at 75 kVp = 14.06 mGy.cm 2 ; 85 kVp = 7.47 mGy.cm 2. Average lumbar spine DAP at 80 kVp = 15.76 mGy.cm 2 ; 90 kVp = 14.83 mGy.cm 2. Image quality and contrast scores showed no statistically significant difference between the high and low kVp groups (z = 0.06 and 0.12, respectively). Average pelvis VGA score at 75 kVp = 11.26; 85 kVp = 12.55. Average lumbar spine VGA score at 80 kVp = 9.23; 90 kVp = 10.64. Conclusions: The high tube potential techniques allowed for reduced patient radiation doses whilst showing no degradation of diagnostic image quality in a clinical setting. This study successfully validates the high kVp technique as a useful tool for reducing patient radiation doses whilst maintaining high diagnostic image quality for digital pelvis and lumbar spine radiography.

In the UK, as elsewhere, there is potential to improve how radiological challenges are addressed through improvement in, or development of, a strong radiation protection (RP) safety culture. In preliminary work in the UK, two areas have been identified as having a strong influence on UK society: the healthcare and nuclear industry sectors. Each has specific challenges, but with many overlapping common factors. Other sectors will benefit from further consideration.In order to make meaningful comparisons between these two principal sectors, this paper is primarily concerned with cultural aspects of RP in the working environment and occupational exposures rather than patient doses.The healthcare sector delivers a large collective dose to patients each year, particularly for diagnostic purposes, which continues to increase. Although patient dose is not the focus, it must be recognised that collective patient dose is inevitably linked to collective occupational exposure, especially in interventional procedures.The nuclear industry faces major challenges as work moves from operations to decommissioning on many sites. This involves restarting work in the plants responsible for the much higher radiation doses of the 1960/70s, but also performing tasks that are considerably more difficult and hazardous than those original performed in these plants.Factors which influence RP safety culture in the workplace are examined, and proposals are considered for a series of actions that may lead to an improvement in RP culture with an associated reduction in dose in many work areas. These actions include methods to improve knowledge and awareness of radiation safety, plus ways to influence management and colleagues in the workplace. The exchange of knowledge about safety culture between the nuclear industry and medical areas may act to develop RP culture in both sectors, and have a wider impact in other sectors where exposures to ionising radiations can occur.

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Identification of hypoperfused areas in myocardial perfusion single-photon emission tomography studies can be aided by bull's-eye representation of raw counts, lesion extent and lesion severity, the latter two being produced by comparison of the raw bull's-eye data with a normal data base. An artificial intelligence technique which is presently becoming widely popular and which is particularly suitable for pattern recognition is that of artificial neural network. We have studied the ability of feed forward neural networks to extract patterns from bull's-eye data by assessing their capability to predict lesion presence without direct comparison with a normal data base. Studies were undertaken on both simulation data and on real stress-rest data obtained from 410 male patients undergoing routine thallium-201 myocardial perfusion scintigraphy. The ability of trained neural networks to predict lesion presence was quantified by calculating the areas under receiver operating characteristic curves. Figures as high as 0.96 for non-preclassified patient data were obtained, corresponding to an accuracy of 92%. The results demonstrate that neural networks can accurately classify patterns from bull's-eye myocardial perfusion images and detect the presence of hypoperfused areas without the need for comparison with a normal data base. Preliminary work suggests that this technique could be used to study perfusion patterns in the myocardium and their correlation with clinical parameters.

The improvement of mammographic specificity was investigated by means of identifying specific radiological features. Data are presented on the first 500 patients studied who had previously undergone mammography followed by biopsy. The presence of specific mammographic features on each radiograph, first determined by retrospective examination, was entered into a computer database. Subsequent discriminant function analysis demonstrated the importance of a small number of features whose presence could be used in an algorithm to predict diagnostic outcome. Using this algorithm, this feature-identification approach correctly identified 87.6% of benign and 79% of malignant cases. Specificity was improved to 88% as compared with the original radiological diagnosis of 49%. It is argued that this approach is very promising and a computer-assisted diagnosis based on these findings is described.