Thesis submitted in fulfilment of the requirements for the award of the
degree of
Master of Technology Radiography (Diagnostic)
in the Faculty of Health and Wellness Sciences
at the Cape Peninsula University of Technology
2009 / Since their discovery in 1895, the use of x-rays is continuously evolving in medicine
making the diagnosis of injuries and diseases more practicable. It is therefore not
surprising that x-rays contribute 90% of the radiation dose to the population from manmade
sources (DWP, 1992). Moreover, these radiation doses are associated with both
fatal and non-fatal cancer risk that is detrimental to adults between 20 to 60 years (Wall,
1996). Radiation dose to individuals therefore needs to be actively monitored in order to
minimise such risk. Barium contrast examinations were characterised as one of the
radiological examinations that contributed enormously to the collective dose to the
patients in the radiology department (DWP, 1992). Determining the diagnostic reference
levels of such examinations would reduce the over-exposure of individuals to ionising
radiation. Currently in South Africa (SA), there are no diagnostic dose reference levels
for barium meal (BaM) and barium enema (BaE) examinations. This study therefore
investigated the radiation doses delivered to patients referred for BaM and BaE,
obtained potential regional reference doses for these examinations, compared the
radiation doses obtained with those from similar dosimetry studies and investigated
sources of dose variation among the study sites.
A total of 25 BaM and 30 BaE patients in the age range 18 to 85 years, weighing 50 kg
to 90 kg, at 3 hospitals in the Western Cape, SA were investigated. The radiation dose
to the patients was measured using Dose Area Product (DAP) meters that were
permanently fitted onto fixed fluoroscopy units at these 3 hospitals. The third quartile
DAP values were 20.1 Gycm2 and 36.5 Gycm2 for BaM and BaE respectively. The
median DAP values were 13.6 Gycm2 and 27.8 Gycm2 for BaM and BaE respectively.
The median values were recommended as the potential Diagnostic Reference Levels for
BaM and BaE as they are less affected by outlying values of under or over- weight
(Yakoumakis, Tsalafoutas, Sandilos, Koulentianos et al, 1999). The weights of the
patients, fluoroscopy time, the number of images obtained, the use of digital or
conventional fluoroscopy equipment and the level of training of the radiologists were the
factors considered for dose variation among the 3 hospitals.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:cput/oai:localhost:20.500.11838/1560 |
| Date | January 2009 |
| Creators | Nabasenja, Caroline |
| Publisher | Cape Peninsula University of Technology |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | http://creativecommons.org/licenses/by-nc-sa/3.0/za/ |
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