dc.contributor.author | Marenya, Umara P | |
dc.date.accessioned | 2013-05-23T11:45:29Z | |
dc.date.available | 2013-05-23T11:45:29Z | |
dc.date.issued | 2003 | |
dc.identifier.citation | Masters in Diagnostic radiology of the University of Nairobi, 2003 | en |
dc.identifier.uri | http://erepository.uonbi.ac.ke:8080/xmlui/handle/11295/24843 | |
dc.description.abstract | Radiation is always a medical concern as it may induce cancer and
hereditary defects ..The use of CT has increased rapidly in the past
decade due to the increased medical diagnostic applications of this
imaging modality. This has resulted in an increasing medical
radiation burden associated with CT. Doses should therefore be kept
as low as reasonably achievable in line with the ALARA principle.
Objective: The main objective of the study was to generate baseline
data in patients' radiation skin doses during abdominal CT scan
examination and to assess the associated risks to certain critical
organs.
Study Design: The study was comparative and cross sectional.
Study Setting: The study was conducted at MITC and involved
eighty-one patients who presented for-C'T scan examinations of the
abdomen between September 2002 and March 2003.
Subject/Patients: Eighty-one patients presented for abdominal CT
examinations. Thirty-five patients underwent conventional CT
examination at MP Shah while thirty-six patients underwent spiral
CT examination at MITC. Ten patients were assessed for radiation
skin dose during topogram examination at MP Shah.
Method: Radiation doses were measured by use of Thermolumiscent
Dosimeters (Lithium Fluoride), which were placed before the CT
scan examination on the skin corresponding to the Thyroid gland,
Liver, Breasts and Testis. The amount of radiation absorbed by the
dosimeters was determined by reading their light output in the
Thermoluminiscent Dosimeter Reader at the Department of
Diagnostic radiology (U.O.N).
The dosimeters were earlier calibrated using cobalt-60 radiation to
determine their response to a certain uniform amount of radiation.
Results: Dose calculations for each region e.g. liver, breast, thyroid,
and testis were done for each patient. Data was entered into a
microcomputer using SPSS/PC data entry programme. Geometric
means for radiation dose to the various skin sites were calculated.
The results showed that mean dose was highest for liver (sequential
CT- 88.8mGy, spiral CT-92.8mGy), followed by Breast (sequential-
9.89mGy, Spiral-lOmGy), Thyroid (sequential-2.85mGy, Spiral-
2.52mGy) and was lowest for the Testis (sequential-l.23mGy,
Spiral-l.33mGy). Results also showed that there was no significant
difference in skin doses delivered during conventional and spiral CT
examination. The dose delivered by Topogram examination relative
to the multi-slice examination were insignificant to the liver, breast,
and thyroid while it was significant to the testis denoting that the
topogram contributed to most of the testis skin dose.
Conclusion
There was no significant difference in skin doses at sequential or
spiral CT examinations. The skin doses in this study were generally
below radiation dose levels required to induce deterministic effects
like causing temporary or permanent sterility of the testis. The choice
of whether to use spiral or conventional CT should therefore rely on
clinical considerations rather than on dose. | en |
dc.language.iso | en | en |
dc.publisher | University of Nairobi | en |
dc.title | Radiation skin doses to patients undergoing abnomal computed tomographic examinations | en |
dc.type | Thesis | en |
dc.description.department | a
Department of Psychiatry, University of Nairobi, ; bDepartment of Mental Health, School of Medicine,
Moi University, Eldoret, Kenya | |
local.publisher | School of Medicine | en |