Optimization of patient radiation protection in pelvic X-ray examination in Ghana.

Pelvis X-ray examinations inevitably involve exposure of the gonads to ionizing radiation. In line with the principle of keeping doses as low as reasonably practicable (ALARP), accurate patient dose measurement is vital if we are to ascertain that these exposures are fully optimized. The study aimed to provide patient dose estimates for pelvis examination being undertaken at 10 separate hospitals in Ghana in order to provide an initial quantitative indication of each site's typically achievable radiation safety and quality standards. The method employed was adapted from established methods and peer reviewed literature, such as the International Atomic Energy Agency (IAEA) publications on optimization of the radiological protection of patients undergoing radiography, fluoroscopy, and computed tomography examinations in some countries in Africa, Asia, and Eastern Europe. Dose measurements were calculated on 323 patients (137 (42%) male, 186 (58%) female, ages, 38.56 yr ± 9.0; range 20-68). The entrance surface dose (ESD) was determined by an indirect method, using the patient's anatomical data and exposure parameters utilized for the specific examination. The Quality Assurance Dose Database software (QADDs) developed by Integrated Radiological Services Ltd. in Liverpool, UK was used to generate the ESD values. The study identified variations in the technique factors used compared with the recommendations in the European Commission (EC) quality criteria. Eighty percent of the hospitals recorded lower ESD values below IAEA recommended diagnostic reference levels (10 mGy) and 40% of the hospitals exceeded the UK national reference value (4 mGy). However, one hospital consistently recorded higher ESDs than the other hospitals. The variations in the data recorded demonstrate the importance of creating awareness by the radiographic staff on quality assurance and standardization of protocols to ensure satisfactory standards and optimized radiation dose to patients and staff.

Acquisition and interpretation of focused diagnostic ultrasound images by ultrasound-naive advanced paramedics: trialling a PHUS education programme.

OBJECTIVE: This trial investigated whether advanced paramedics from a UK regional ambulance service have the ability to acquire and interpret diagnostic quality ultrasound images following a 2-day programme of education and training covering the fundamental aspects of lung ultrasound. METHOD: The participants were tested using a two-part examination; assessing both their theoretical understanding of image interpretation and their practical ability to acquire diagnostic quality ultrasound images. The results obtained were subsequently compared with those obtained from expert physician sonographers. RESULTS: The advanced paramedics demonstrated an overall accuracy in identifying the presence or absence of pneumothorax in M-mode clips of 0.94 (CI 0.86 to 0.99), compared with the experts who achieved 0.93 (CI 0.67 to 1.0). In two-dimensional mode, the advanced paramedics demonstrated an overall accuracy of 0.78 (CI 0.72 to 0.83), compared with the experts who achieved 0.76 (CI 0.62 to 0.86). In total, the advanced paramedics demonstrated an overall accuracy at identifying the presence or absence of pneumothorax in prerecorded video clip images of 0.82 (CI 0.77 to 0.86), in comparison with the expert users of 0.80 (CI 0.68 to 0.88). All of the advanced paramedics passed the objective structured clinical examination and achieved a practical standard considered by the examiners to be equivalent to that which would be expected from candidates enrolled on the thoracic module of the College of Emergency Medicine level 2 ultrasound programme. CONCLUSION: This trial demonstrated that ultrasound-naive practitioners can achieve an acceptable standard of competency in a simulated environment in a relatively short period of time.

Accounting for bias due to a non-ignorable tracing mechanism in a retrospective breast cancer cohort study.

We consider the analysis of competing risks in a retrospective breast cancer cohort study where tracing of patients is dependent on survival to a pre-specified truncation time. We demonstrate that if ignored, the observed cause-specific hazards will become distorted before the truncation time. Two approaches to account for the tracing bias are considered. First, a likelihood-based method using piecewise constant transition intensities under a Markov assumption. Second, a pseudo-likelihood method using inverse probability of tracing weights. For the breast cancer example, both methods improve the precision of estimates compared with a conventional approach based on excluding patients.

Paramedic application of ultrasound in the management of patients in the prehospital setting: a review of the literature.

OBJECTIVES: Recently, attempts have been made to identify the utility of ultrasound in the management of patients in the prehospital setting. However, in the UK there is no directly relevant supporting evidence that prehospital ultrasound may reduce patient mortality and morbidity. The evidence available to inform this debate is almost entirely obtained from outside the UK, where emergency medical services (EMS) routinely use doctors as part of their model of service delivery. Using a structured review of the literature available, this paper examines the evidence to determine 'Is there a place for paramedic ultrasound in the management of patients in the prehospital setting?' METHOD: A structured review of the literature to identify clinical trials which examined the use of ultrasound by non-physicians in the prehospital setting. RESULTS: Four resources were identified with sufficient methodological rigour to accurately inform the research question. CONCLUSION: The theoretical concept that paramedic-initiated prehospital ultrasound may be of benefit in the management of critically ill patients is not without logical conceptual reason. Studies to date have demonstrated that with the right education and mentorship, some paramedic groups are able to obtain ultrasound images of sufficient quality to positively identify catastrophic pathologies found in critically ill patients. More research is required to demonstrate that these findings are transferable to the infrastructure of the UK EMS, and in what capacity they may be used to help facilitate optimal patient outcomes.

Breast asymmetry and predisposition to breast cancer.

INTRODUCTION: It has been shown in our previous work that breast asymmetry is related to several of the known risk factors for breast cancer, and that patients with diagnosed breast cancer have more breast volume asymmetry, as measured from mammograms, than age-matched healthy women. METHODS: In the present study, we compared the breast asymmetry of women who were free of breast disease at time of mammography, but who had subsequently developed breast cancer, with that of age-matched healthy controls who had remained disease-free to time of the present study. The study group consisted of 252 asymptomatic women who had normal mammography, but went on to develop breast cancer. The control group were 252 age-matched healthy controls whose mammograms were also normal and who remained free of cancer during the study period. Breast volume was calculated from the cranio-caudal mammograms for each group, and the relationships between asymmetry, established risk factors and the presence or absence of breast cancer were explored. RESULTS: The group who went on to develop breast cancer had higher breast asymmetry than controls (absolute asymmetry odds ratio 1.50 per 100 ml, confidence interval (CI) 1.10, 2.04; relative asymmetry 1.09, CI 1.01, 1.18), increased incidence of family history of breast cancer, lower age at menarche, later menopause, later first pregnancies and a higher frequency of high risk breast parenchyma types. Conditional logistic regression analysis showed that breast asymmetry, height, family history of breast cancer, age at menarche, parenchyma type and menopausal status were significant independent predictors of breast cancer. When age at menopause was included in the model for the subgroup of post-menopausal women, absolute breast fluctuating asymmetry (FA) and relative breast FA remained significant effects. CONCLUSION: Breast asymmetry was greater in healthy women who later developed breast cancer than in women who did not.

N-nitrosodiethylamine-induced pig liver hepatocellular carcinoma model: radiological and histopathological studies.

Experimental research involving animal models plays a critical role in the development and improvement of minimally invasive therapies for hepatocellular carcinoma (HCC). As a large animal, the pig is commonly used for surgery and interventional radiology research. In this study, liver multicentric HCC with cirrhosis was induced in six China Taihu pigs by intraperitoneal injection of 10 mg/kg of N-nitrosodiethylamine once a week for 3 months, followed by a period of 10-12 months without N-nitrosodiethylamine treatment. All pigs were in generally good health until the end of the study. The tumor nodules appeared hyperattenuating in the arterial phase of a dynamic computed tomography (CT) scan. Digital subtraction angiography (DSA) and CT angiography demonstrated that the tumors derived their blood supply mainly from the hepatic artery system. Lipiodol-CT showed Lipiodol retention in tumor areas. The histology and electron microscopic ultrastructure of the chemically induced liver HCC in this study resembled human HCC with a cirrhosis background. An immunohistochemistry study confirmed that the tumors were of hepatocyte origin. All highly, moderately, and poorly differentiated HCC tumors were identified in this study. Cholangiocarcinoma was not seen in any of the animals. Due to its comparable size to human anatomy, the pig liver HCC model would give a better scope for interventional and surgical manipulations than small animal models.

Effects of oral sodium picosulphate Picolax on urea and electrolytes.

AIM: To investigate the effects of sodium picosulphate (Picolax) oral bowel preparation on levels of serum urea, electrolytes and glucose in patients undergoing bowel preparation for barium enema. METHOD: A prospective, non-randomised, pre-test and post-test trial was conducted with 144 patients aged 34-87 years, who had agreed to undergo a barium enema. Changes in serum urea, sodium, potassium, magnesium and glucose following Picolax treatment were investigated. RESULTS: There were statistically significant post-Picolax reductions in serum concentrations of urea (mean difference 0.556 (95 per cent confidence intervals (CI) 0.321-0.791) mmol/L), sodium (mean difference 1.299 (0.799-1.799) mmol/L) and potassium (mean difference 0.163 (0.0853-0.241) mmol/L). Similar findings were observed for sodium and urea when the sample was stratified according to age: under 60 years (n=56) or 60 years and over (n=88). However, there was no significant change in potassium in patients aged under 60 years. CONCLUSION: In normal circumstances, use of Picolax oral bowel preparation results in a statistically, but not clinically, significant reduction in concentration of serum urea, sodium and potassium.