| Author: | So, Pui-wai. |
| Title: | Investigation of the dose reduction methods in C-arm fluoroscopy |
| Degree: | M.Sc. |
| Year: | 2006 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Radiation -- Dosage Fluoroscopy |
| Department: | Department of Optometry and Radiography |
| Pages: | xii, 72 leaves : ill. (some col.) ; 30 cm. |
| Language: | English |
| Abstract: | The number of interventional radiological (IR) procedures and fluoroscopic guided procedures are increasing in recent years. These procedures are less invasive and can shorten the time for hospitalization. However, these procedures induce comparatively high dose to both patients and staff due to the complexity of the examination that requires longer exposure time. Literatures suggested many ways that can reduce both patient's and staff's dose. The aim of this study is to evaluate the effects of tube geometry, magnification, collimation and object-I.I. distance on the degree of dose reduction for patients and staff. High sensitivity LiF:Mg,Cu,P thermoluminescent dosemeters (TLD) and a tissue equivalent phantom were used. Experiments were performed at the Radiology Department of the Caritas Medical Center. Results were tabulated and pair t-test and simple linear regression were performed to test the differences. The results for the effect of geometry showed that operator's doses including skin dose (at table level), hand, eye and testis decreased when the image intensifier (I.I.) was closed to the operator and when the operator stands at the I.I. side. The operator's entrance skin dose (ESD) can be reduced by a factor of 9 when he/she stands at the I.I. rather than in the tube side. Results on the effect of magnification showed that when using a smaller I.I. input field size, patient's ESD would increase. However, patient's testis dose, operator's ESD, hand, eye and testis dose would decrease. When using the magnified mode, patient's ESD increased from a range of 197% to 25 1%. For the effect of variation of object-I.I. distance, results showed that the greater the distance, the greater the radiation dose delivered both to patient and staff. The range of increment ranged from 1.3% to 9% per cm increase of the distance. Results of the effect of collimation were similar to those of magnification. Results showed that larger collimation size will deliver less patient's ESD but greater patient's testis, operator's ESD, hand, eye and testis doses. The radiation dose reduction methods investigated in this study are easy to achieve, simple, not time and cost consuming. The principle is simple but not everyone pay attention on it. Both patient and staff can enjoy the benefit if we pay more concern on our daily practice and maintain the good practice. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b19681318.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 4.61 MB | Adobe PDF | View/Open |
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