Influence of dose reduction recommendations on changes in chest radiography techniques
| Autor: | M J Haddaway, D H Temperton, Helen Warren-Forward, I W McCall |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Medical Audit
business.industry West midlands Radiography General Medicine Applied potential Radiation Dosage Collective dose Radiology procedures Practice Guidelines as Topic Humans Medicine Dosimetry Radiography Thoracic Radiology Nuclear Medicine and imaging Dose reduction Statistical analysis Practice Patterns Physicians' business Nuclear medicine |
| Zdroj: | The British Journal of Radiology. 69:755-761 |
| ISSN: | 1748-880X 0007-1285 |
| Popis: | A previous dosimetric study on chest radiography identified ways to reduce patient entrance surface dose (ESD). This present study was designed to monitor changes that had occurred in the use of applied potential and film-screen sensitivity, after a series of recommendations were issued. The study falls into two parts: (1) an assessment of the impact of the recommendations and (2) what factors were responsible for change. Where changes had occurred, exposure factors were collected for 30 patients per tube and the mean ESD was calculated for each tube. Intercomparison (r = 0.93, p< 0.001) was made between calculated and measured (TLDs) values of mean ESD for 10 X-ray units, to ensure that the calculated values provided accurate estimates of the new mean ESDs. 89% of units previously monitored for patient ESD now use average applied potentials greater than 90 kVp and 51% are using film-screen sensitivities of 400. The mean ESD has been reduced on average by 47%, from 0.15 mGy to 0.08 mGy. It has been estimated that the annual collective dose from diagnostic radiology procedures in 30 hospitals in the West Midlands has been reduced by a value in excess of 40 man Sv. Reasons for change could be attributed to some of the following factors: (a) a knowledge of dose levels in comparison with other centres; (b) personal contact with departments; (c) feedback in terms of results and dose savings and (d) positive encouragement to make changes. A dosimetric study (1991-1994) on chest radiography has identified ways to reduce patient entrance surface dose (ESD), while maintaining adequate levels of image quality [1]. The ESDs were monitored with lithium borate thermoluminescent dosemeters (TLDs) in accordance with the National Protocol [2] . The variation of results between different departments was similar to a number of national and regional dose surveys [3-5] . Image quality was assessed with the use of the Commission of the European Communities (CEC) quality criteria [6]. Minor changes were made to the criteria after discussions with a number of radiologists in the West Midlands. Actual film-screen processor sensitivity was also monitored for each department, using their own film-screen and processor systems; the results showed agreement with other studies in that there were large discrepancies between nominal and actual sensitivities [7,8], indicating non-optimization of the imaging systems. |
| Databáze: | OpenAIRE |
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