The log file generated in the flat panel detector of a direct digital x-ray machine (General Electric, Haulun Medical Systems, Serial Number 8M0392) after x-ray exposure was used to acquire data regarding the entrance surface air kerma (ESAK) for some routine x-ray examinations. The data were collected for a minimum of 10 standard adult patients undergoing each examination considered. The mean ESAK were found to be 0.25, 0.33, 0.14, 7.33, 9.76, 7.38, and 6.86 mGy for skull AP and LAT, chest AP, lumbar spine AP and LAT, pelvis AP and abdomen AP series, respectively. The mean ESAK values recorded from this study show wide variations but were below diagnostic reference levels (DRLs) of the Commission of European Communities and also compare with other recommendations. The comparisons of this study's dose levels with DRLs were undertaken as an approach to dose optimization. The study revealed that a dose audit of digital radiography systems is necessary because of the potential high doses one is likely to receive. Continuous dose evaluation in digital radiography is therefore encouraged in order to optimize doses to patients.

Organ and effective doses to 90 patients undergoing some selected fluoroscopic examinations at the Korle-Bu Teaching Hospital were estimated using the Monte Carlo-based program (PCXMC version 1.5). Radiation dose was estimated from free-in-air measurements. The mean effective doses were found to be 0.29 +/- 0.07, 0.84 +/- 0.13, 3.15 +/- 0.44, 6.24 +/- 0.70 and 0.38 +/- 0.05 mSv for urethrogram, barium swallow, barium meal, barium enema and myelogram examinations, respectively. The dose area product was estimated to be 3.55 +/- 0.95, 16.44 +/- 2.60, 50.81 +/- 7.04, 99.69 +/- 10.85 and 9.32 +/- 0.99 Gy cm(2) for urethrogram, barium swallow, barium meal, barium enema and myelogram examinations, respectively. Optimisation of procedures is required for barium enema and barium meal examinations.

Studies have shown that there is high radiation exposure to medical staff during computed tomography fluoroscopy (CTF)-guided procedures. This study aims to investigate staff dose reduction techniques considering the CTF gantry positioning in the room and room dimensions in addition to the conventional use of thyroid collars, aprons and eye goggles. A Toshiba Aquilion One 640 slice CT scanner and CTF room were modelled using SimpleGeo. Standing and supine adult mesh phantoms were used to represent the staff and patient. The models were spatially put together on one platform using VOXEL2MCNP. Based on this, MCNPX input files were generated for the studies. CTF gantry and staff positions, and CTF room size were varied for different scenarios. Effective, eye lens and thyroid dose to staff were estimated for each scenario. Additional means of possible dose reduction with respect to positioning of the CTF device and room layout are discussed.

Cancer incidence estimates and dosimetry of 120 patients undergoing hysterosalpingography (HSG) without screening at five rural hospitals and with screening using image intensifier-TV at an urban hospital have been studied. Free in air kerma measurements were taken for patient dosimetry. Using PCXMC version 1.5, organ and effective doses to patients were estimated. Incidence of cancer of the ovary, colon, bladder and uterus due to radiation exposure were estimated using biological effects of ionising radiation committee VII excess relative risk models. The effective dose to patients was estimated to be 0.20 ± 0.03 mSv and 0.06 ± 0.01 mSv for procedures with and without screening, respectively. The average number of exposures for both procedures, 2.5, and screening time of 48.1 s were recorded. Screening time contributed majority of the patient doses due to HSG; therefore, it should be optimised as much as possible. Of all the cancers considered, the incidence of cancer of the bladder for patients undergoing HSG procedures is more probable.

The status of radiation protection and safety of diagnostic medical x-ray facilities in the Greater Accra region in Ghana have been evaluated. In all, 62 medical facilities with 86 diagnostic x-ray units were considered for the survey. Out of the 86 diagnostic units, there were 56 general radiograph, 13 dental radiography, 9 fluoroscopy, 5 computed tomography, and 3 mammography machines. The parameters evaluated include the tube voltage, type of film processor, and the required protective measures in an x-ray department. It was observed that none of the protective measures or equipment were fully present in the diagnostic units except lead aprons. The radiation protection and safety measures in the medical facilities need to be strengthened to protect patients, staff, and the general public.