Estimation of organ-specific cancer and mortality risks associated with common indication-specific CT examinations of the abdominopelvic region.

Introduction: There is a paucity of large-scale studies reporting organ doses and cancer risks in patients who undergo indication-specific CT examinations. This study estimated organ-specific lifetime attributable risk (LAR) of cancer incidence and mortality among patients who underwent indication-based computed tomography (CT) examinations [(involving abdominopelvic lesion, kidney stones and computed tomography-intravenous urography (CT-IVU)] in about 70% of the functioning CT facilities in Ghana.

Methods: With a total of 1,100 data sets, organ doses were first determined using the National Cancer Institute Dosimetry System for CT (NCICTX) software version 2.

Adult Computed Tomography examinations in Uganda: Towards determining the National Diagnostic Reference Levels.

Introduction: Diagnostic Reference Levels (DRLs), typically set at the 75th percentile of the dose distribution from surveys conducted across a broad user base using a specified dose-measurement protocol, are recommended for radiological examinations. There is a need to develop and implement DRLs as a standardisation and optimisation tool for the radiological protection of patients at Computed Tomography (CT) facilities.

Methods: This was a retrospective cross-sectional study conducted in seven (7) different CT scan facilities in which participants were recruited by systematic random sampling.

Towards the establishment of national imaging practice guidelines: A preliminary study of the basic computed tomography imaging protocols in Ghana.

Background: There is a need to harmonize imaging practices in computed tomography (CT) imaging. This study, therefore, investigated the variability of the basic imaging protocols used for CT imaging of common indications in Ghana in order to generate recommendations for the development of national imaging practice guidelines in CT imaging.

Method: A cross-sectional study, utilizing a structured online questionnaire, was undertaken (between December 2018 to March 2019) to collect indication-based imaging protocol data (scan coverage, scan series, image quality requirement, slice thickness, reconstruction, scan mode and orientation, required window, AEC usage, scan and breath hold techniques etc.

Variability of redundant scan coverages along the Z-axis and dose implications for common computed tomography examinations.

Background: Scan length optimization is a method of optimization which ensures that, imaging is performed to cover just the area of interest without unnecessarily exposing structures that would not add value to answer a given clinical question.

Purpose: This study assessed the variability and degree of redundant scan coverages along the z-axis of CT examinations of common indications and the associated radiation dose implications in CT facilities in Ghana for optimization measures to be recommended.

Methods: On reconstructed acquired CT images, the study measured extra distances covered above and below anatomical targets for common indications with calibrated calipers across 25 CT facilities.

ASSESSMENT OF MEASUREMENT UNCERTAINTY FOR THE MEASUREMENT OF THE QUANTITY PERSONAL DOSE EQUIVALENT HP (10) IN PHOTON FIELDS USING THE GUM FRAMEWORK AND THE MONTE CARLO METHODS: APPLICATION TO GABON RESULTS OBTAINED DURING THE 2018 IAEA REGIONAL INTERCOMPARISON EXERCISE.

This paper describes the essential of the "Guide to the expression of Uncertainty in Measurement" Framework (GUMF) Method and Monte Carlo Method (MCM) for propagating uncertainties, with an application to Gabon results obtained during the 2018 International Atomic Energy Agency (IAEA) regional intercomparison exercise. The work has shown that the output quantity Hp (10) follows a lognormal distribution. The study has also shown that although the normal distribution does not best approximate the distribution of the output quantity Hp (10), it has been observed that its estimate, the associated standard uncertainty and the coverage interval determined by GUMF and MCM were close, meaning that the application of the GUMF could still be seen as valid.

National indication-based diagnostic reference level values in computed tomography: Preliminary results from Ghana.

Purpose: This study was conducted to develop national indication-based DRL values for common indications of adult computed tomography (CT) examinations for clinical application in Ghana.

Materials And Methods: The methodological approach recommended by the International Commission on Radiological Protection (ICRP), Publication 135, for the development of DRLs, was employed. Studies on CT infrastructure, common indications and quality control tests were first undertaken.

Status of Quality Management Systems in Computed Tomography Facilities in Ghana.

Purpose: To assess the status of quality management systems in computed tomography (CT) facilities in Ghana.

Methods: A questionnaire and quality control measurements were used to assess the status of quality management systems in CT facilities in Ghana. Thirty-one CT facilities took part in the study.

An Investigation into the Infrastructure and Management of Computerized Tomography Units in Ghana.

Introduction: In Ghana, there is a need to document computed tomography (CT) infrastructure and management systems for the development of interventions to promote CT practices while ensuring patient protection through the establishment of diagnostic reference levels and improved dose management systems.

Methods: A quantitative inquiry using a descriptive, cross-sectional approach was used to collect data, using a semistructured questionnaire related to CT infrastructure and management from the technical heads responsible for CT scanners. Data collected included the scanner characteristics, basic management system and organizational arrangements, number of attending practitioners, clinical indications for CT examinations, and the operation of CT facilities in Ghana.

INTERCOMPARISON ON THE MEASUREMENT OF THE QUANTITY PERSONAL DOSE EQUIVALENT HP(10) IN PHOTON FIELDS. LINEARITY DEPENDENCE, LOWER LIMIT OF DETECTION AND UNCERTAINTY IN MEASUREMENT OF DOSIMETRY SYSTEMS OF INDIVIDUAL MONITORING SERVICES IN GABON AND GHANA.

An inter-comparison study was conducted to assess the capability of dosimetry systems of individual monitoring services (IMSs) in Gabon and Ghana to measure personal dose equivalent Hp(10) in photon fields. The performance indicators assessed were the lower limit of detection, linearity and uncertainty in measurement. Monthly and quarterly recording levels were proposed with corresponding values of 0.

Medical physics practice and training in Ghana.

Medical physics has been an indispensable and strategic stakeholder in the delivery of radiological services to the healthcare system of Ghana. The practice has immensely supported radiation oncology and medical imaging facilities over the years, while the locally established training programme continues to produce human resource to feed these facilities. The training programme has grown to receive students from other African countries in addition to local students.

PAEDIATRIC NECK MULTIDETECTOR COMPUTED TOMOGRAPHY: THE EFFECT OF BISMUTH SHIELDING ON THYROID DOSE AND IMAGE QUALITY.

This study investigated the effect of bismuth shielding on thyroid dose and image quality in paediatric neck multidetector computed tomography (MDCT) performed with fixed tube current (FTC) and automatic exposure control (AEC). Four paediatric anthropomorphic phantoms representing the equivalent newborn, 1-, 5- and 10-y-old child were subjected to neck CT using a 16-slice MDCT system. Each scan was performed without and with single- and double-layered bismuth shield placed on the skin surface above the thyroid.

Natural radioactivity levels of some medicinal plants commonly used in Ghana.

Natural radioactivity levels in some selected medicinal plants commonly used in Ghana from the Centre for Scientific Research into Plant Medicine were investigated to determine the activity concentration and the annual committed effective dose due to naturally occurring radionuclides of (238)U, (232)Th and (40)K. The activity concentration was determined using gamma-ray spectrometry. The results of the analysis indicated an average activity concentration of (238)U, (232)Th and (40)K in the medicinal plants to be 31.

Assessment of the integrity of structural shielding of four computed tomography facilities in the greater Accra region of Ghana.

The structural shielding thicknesses of the walls of four computed tomography (CT) facilities in Ghana were re-evaluated to verify the shielding integrity using the new shielding design methods recommended by the National Council on Radiological Protection and Measurements (NCRP). The shielding thickness obtained ranged from 120 to 155 mm using default DLP values proposed by the European Commission and 110 to 168 mm using derived DLP values from the four CT manufacturers. These values are within the accepted standard concrete wall thickness ranging from 102 to 152 mm prescribed by the NCRP.

Personal dose analysis of TLD glow curve data from individual monitoring records.

Radiation exposure of workers in Ghana have been estimated on the basis of personal dose records of the occupationally exposed in medical, industrial and research/teaching practices for the period 2008-09. The estimated effective doses for 2008 are 0.400, 0.

Investigation of the environmental impacts of naturally occurring radionuclides in the processing of sulfide ores for gold using gamma spectrometry.

The possible environmental impacts of naturally occurring radionuclides on workers and a critical community, as a result of milling and processing sulfide ores for gold by a mining company at Bogoso in the western region of Ghana, have been investigated using gamma spectroscopy. Indicative doses for the workers during sulfide ore processing were calculated from the activity concentrations measured at both physical and chemical processing stages. The dose rate, annual effective dose equivalent, radium equivalent activity, external and internal hazard indices, and radioactivity level index for tailings, for the de-silted sediments of run-off from the vicinity of the tailings dam through the critical community, and for the soils of the critical community's basic schools were calculated and found to be lower than their respective permissible limits.

Systematic approach to training occupationally exposed workers in Ghana and the rest of Africa.

The International Basic Safety Standards requires that all personnel on whom protection and safety depends be trained and qualified. The Radiation Protection Institute of the Ghana Atomic Energy Commission has adopted a systematic approach to training those occupationally exposed to ionizing radiation in the course of their work. In collaboration with the International Atomic Energy Agency several training courses have been implemented at the national level and in the African region.

Radiological assessment of the structural shielding adequacy of the radiotherapy facility at Korle-Bu Teaching Hospital, Accra, Ghana.

A (60)Co radiotherapy source with an initial activity of 185 TBq has exhausted its useful half-life and has been replaced with a 222 TBq (60)Co source at the Korle-Bu Teaching Hospital; a radiological assessment was performed to ascertain the shielding integrity of the facility. Dose rate at selected critical positions were calculated for the old and new sources. Dose rate measurements were also performed at these critical locations for the new source.

Radiation doses and hazards from processing of crude oil at the Tema oil refinery in Ghana.

Processing of crude oil has been carried out in Ghana for more than four decades without measures to assess the hazards associated with the naturally occurring radionuclides in the raw and processed materials. This study investigates the exposure of the public to (226)Ra, (232)Th and (40)K in crude oil, petroleum products and wastes at the Tema oil refinery in Ghana using gamma-ray spectrometry. The study shows higher activity concentrations of the natural radionuclides in the wastes than the crude oil and the products with estimated hazard indices less than unity.

Optimization of radiation protection for the control of occupational exposure in Ghana.

Investigation of the optimization of protection of occupational exposed workers (OEWs) in Ghana had been carried out on the three practices in the country, namely medical applications, industrial radioisotope applications and research and education from 2002 to 2007. Mean annual effective dose and collective effective dose were estimated from dosimetry records from the Radiation Protection Institute of those occupationally exposed from 2002 to 2007. The mean annual effective dose estimated for about 650 OEWs per year ranged from 0.

Inter-comparison of safety culture within selected practices in Ghana utilising ionising radiation.

The safety culture of selected practices and facilities in Ghana utilising radiation sources or radiation emitting devices has been assessed using a performance indicator, which provided status information on management and operating staff commitment to safety. The questionnaire was based on the following broad areas: general safety considerations, safety policy at the facility level, safety practices at the facility level, definition of responsibility, staff training, safety of the physical structure of the facility and the emergency plans. The analysis showed that the percentage levels of commitment to safety for the respective practices are as follows: conventional radiography, 23.

Determination of activity concentration levels of (238)U, (232)Th, and (40)K in drinking water in a gold mine in Ghana.

The study of the activity concentration levels of uranium, thorium and potassium in drinking water from different locations in a gold mine in the Ashanti Region of Ghana was conducted using gamma spectrometry. The mean outdoor absorbed gamma dose rates at 1 m from the water were 0.524 nGy h, 0.

Radiation exposure control from the application of nuclear gauges in the mining industry in Ghana.

The use of nuclear gauges for process control and elemental analysis in the mining industry in Ghana, West Africa, is wide spread and on the increase in recent times. The Ghana Radiation Protection Board regulates nuclear gauges through a system of notification and authorization by registration or licensing, inspection, and enforcement. Safety assessments for authorization and enforcement have been established to ensure the safety and security of radiation sources as well as protection of workers and the general public.

Paediatric CT examinations in 19 developing countries: frequency and radiation dose.

The aims of this study were to investigate the frequency of computed tomography (CT) examinations for paediatric patients below 15 y of age in 128 CT facilities in 28 developing countries of Africa, Asia and Eastern Europe and to assess the magnitude of CT doses. Radiation dose data were available from 101 CT facilities in 19 countries. The dose assessment was performed in terms of weighted CT dose index (CTDI(w)), volume CT index and dose length product (DLP) for chest, chest (high resolution), lumbar spine, abdomen and pelvis CT examinations using standard methods.