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Biomedical subjects

N M Tole

Publications and source records attributed to N M Tole.

8 recordsLinked to original sources
PubMed1993

Radiation dose as a factor in the choice of routine pre-operative dental radiographs.

Radiation doses received by patients during dental x-ray examinations were measured in 95 patients referred to the X-ray Department of the Teaching Dental Hospital, University of Nairobi. The mean skin dose for single periapical films was 5.96 milligray (596 millirads) with the bitewing view recording a mean dose of 5.57 milligray (mGy). During a 14-film full-mouth periapical survey, mean doses ranged from 10.3-16.2 mGy for the upper jaw and 10.1-13.5 mGy for the lower jaw, respectively, depending on the region of dentition. In these full-mouth examinations, the distribution of skin dose over different parts of the dentition showed a characteristic pattern which may be explained by the overlap of radiation fields in the aggregated series of exposure. Orthopantomography recorded lower mean skin doses of 3.26 mGy in the molar region and 2.67 mGy at the posterior midline at the level of the 2nd cervical vertebra. The relative merits of intra-oral radiography versus orthopantomography are discussed, with radiation dosage as one of the factors to be considered. Some observations are made on measures to reduce patient dose.

Decision Making↗
PubMed1992

Radiation doses to patients during contrast examinations of the gastrointestinal tract.

Radiation doses received by patients undergoing radiological examinations of the gastrointestinal tract have been measured in 405 patients at two major hospitals in Nairobi using thermoluminescent LiF dosimeters. Skin-entry doses were found to be high at one of the facilities (A) and very high at the other (B). Barium meal delivered mean doses of 77 mGy (7.7 rad) and 558 mGy (55.8 rad) at facilities A and B respectively, while the corresponding mean values for barium enema were 93 mGy (9.3 rad) and 712 mGy (71.2 rad). Differences between the two hospital mean doses were highly significant (p < 0.001). Doses to the thyroid gland and the gonads were also generally higher than those reported in other similar studies. Poor performance of old and ill-maintained radiological equipment, among other possible factors, is suggested to be the main cause of excessive patient exposure. Radiation risks to patients are considered in the context of such high doses being received by a generally young patient population. The authors suggest that there ought to be limits on the extent to which social and economic considerations in the provision of radiological services should be allowed to compromise sound principles in the radiation protection of the patient. It is recommended that increased efforts be directed at establishing and supporting quality assurance programmes for the performance testing of radiological equipment in Africa.

Adolescent↗
PubMed1989

An estimate of the frequency of diagnostic X-ray examinations in Kenya in 1986.

The frequency of radiological examinations in a country is an important indicator of the general scope of such services in that setting. Frequency data obtained from surveys provide health planners with valuable information that can form an objective basis for resource allocation. Also, from the point of view of radiation protection, the collection of data on the frequency of different types of radiological examination is one of the essential steps in the process of estimating the collective risks to the population of exposure to diagnostic X-rays. The findings in this study indicate that: radiological coverage of the population is inadequate; simple radiological examinations of the limbs and the chest constitute the bulk of the radiological workload; and some trained radiological staff may be underutilized. These results may have general implications for strategies on the expansion of radiological services in other developing countries.

Health Services↗
PubMed1984

Radiation exposure to patients during radiological examinations of the gastro-intestinal tract: intrahospital dose variations.

Skin and gonad doses have been measured in 144 adult patients undergoing barium meal and barium enema examinations at a University Teaching Hospital. Intrahospital variations are discussed and their implications for national dose surveys considered. It is suggested that, due to differences in leakage and scattered radiation levels, overcouch tube machines may deliver higher doses to organs outside the useful beam than undercouch units. The study also points towards increased film consumption in GIT studies.

Abdomen↗