Increasing beam energies are well established as a radiation dose-reducing tool in diagnostic radiology. This has led to useful recommendations by the Commission of European Communities (CEC) for appropriate kVp values to be employed for a variety of examinations. The current work tests the hypothesis that kVp levels above those recommended by the CEC will result in reduced patient dose while still producing images of acceptable quality. This study explored the effect of a range of kVp levels within and above CEC recommendations for lumbar spine radiology. A phantom investigation facilitated selection of appropriate kVp levels for a patient study ( n=59): 81 kVp (CEC) and 96 kVp (non-CEC) for the AP projection and 90 kVp (CEC) and 102 kVp (non-CEC) for the lateral projection. Entrance surface and effective dose were calculated and image quality quantified using CEC image criteria and images of a detail contrast test tool. Data analysis demonstrated significant reduction in effective radiation dose for AP (29.9%) and lateral (24.6%) when a kVp value above the CEC range was employed compared with a kVp recommended by the CEC. Although significant reductions in total image quality of 18.3% and 10.1% for the antero-posterior and lateral projections, respectively, were noted, all patient images produced with all kVp values were considered acceptable by each member of the evaluative panel with all image criteria receiving a score of 2 (out of 3) or better. The psychophysical tests revealed minor non-significant reductions in visualisation scores. The current study demonstrated that kVp values outside the CEC recommended range offer reductions in dose while producing acceptable images. Practitioners should be guided, rather than constrained, by the CEC recommendations on good radiographic technique. The need for further work exploring the effect of higher energies on visualisation of subtle pathological lesions has been identified.

Data on image quality, compression and radiation dose were collected from symptomatic breast units within the Republic of Ireland. Quantitative and qualitative data were analysed using SPSS. Recommendations of mean glandular dose (MGD) diagnostic reference levels were made at various levels for film-screen and full field digital mammography units to match levels published worldwide. MGDs received by symptomatic breast patients within Ireland are higher than those received in the all-digital Irish Breast Screening service; 55-65 mm breast: 1.75 mGy (screening) vs. 2.4 mGy (symptomatic) at the 95th percentile; various reasons are proposed for the differences. MGDs achieved in the screening service may be lower because of the exacting requirements for radiographer training, characteristics of the patients and equipment quality assurance levels. More precise imaging guidelines, standards and training of symptomatic radiographers performing mammography are suggested to remediate MGDs delivered to the breasts of Irish women attending the symptomatic breast services.

Purpose: To assess whether subjective breast density categorization remains the most useful way to categorize mammographic breast density and whether variations exist across geographic regions with differing national legislation. Methods: Breast radiologists from two countries (UK, USA) were voluntarily recruited to review sets of anonymized mammographic images (n ¼ 180) and additional repeated images (n ¼ 70), totaling 250 images, to subjectively rate breast density according to the Breast Imaging Reporting and Data system (BI-RADS) categorization. Images were reviewed using standardized viewing conditions and Ziltron software. Inter-rater reliability was analyzed using the Kappa test. Results: The US radiologists (n ¼ 25) judged fewer images as being ''mostly fatty'' than UK radiologists (n ¼ 24), leading a greater number of images classified in the higher BI-RADS categories, particularly in BI-RADS 3. Overall agreement for all data sets was k ¼ 0.654 indicating substantial agreement between the two cohorts. When the data were split into BI-RADS categories, the level of agreement varied from fair to substantial.

This investigation proposes that an increased source to the imagereceptor distance (SID) technique can be used to optimize occipital frontal and lateral cranial radiographs acquired with direct digital radiography. Although cranial radiography is not performed on a routine basis, it should nonetheless be optimized to keep the dose to the patient as low as reasonably achievable, particularly because it can form part of the facial bone and sinus series. Dose measurements were acquired at various SIDs, and image quality was assessed using visual grading analysis. Statistically significant reductions in the effective dose between 19.2% and 23.9% were obtained when the SID was increased from the standard 100 to 150 cm (P .05), and visual grading analysis scores indicate that image quality remained diagnostically acceptable for both projections. This investigation concludes that increasing the SID effectively optimizes occipital frontal and lateral skull radiographs. Radiology departments must be advised of the benefits of this technique with the goal of introducing an updated reference SID of 150 cm into clinical practice.R ESUM E Cette etude pose comme hypoth ese que la technique de l'augmentation de la distance entre la source et le r ecepteur d'image (SID) peut etre utilis ee pour optimiser les radiographies occipitales frontales (OF10 ) et crâniales lat erales acquises par radiographie num erique directe. Bien que la radiographie crâniale ne se pratique pas couramment, elle doit quand mêmeêtre optimis ee pour garder la dose pour le patient la plus basse qui soir raisonnablement possible d'atteindre, notamment parce qu'elle peut s'inscrire dans une s erie de la structure osseuse faciale et des sinus. Des mesures de dose ont et e prises a diff erentes SID et la qualit e de l'image a et e evalu ee au moyen de l'analyse de classement visuel (VGA). Des r eductions statistiquement significatives de la dose variant entre 19,2 % et 23,9 % ont et e obtenues lorsque la SID a et e port ee de la distance standard de 100 cm a 150 cm (p 0,05) et les notes VGA indiquent que la qualit e diagnostique de l'image reste acceptable pour les deux projections. Cette etude conclut que l'augmentation de la SID permet effectivement d'optimiser les radiographies occipitales frontales et crâniales lat erales. Les services de radiographie doiventêtre inform es des avantages de cette technique dans le but d'adopter une mise a jour a 150 cm de la SID de r ef erence dans la pratique clinique.

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