Factors influencing the increased effective dose and dose reduction for abdominal digital radiography
- 주제(키워드) Effective dose , Dose reduction , Abdominal radiography , Digital radiography
- 발행기관 고려대학교 의용과학대학원
- 지도교수 양형진
- 발행년도 2017
- 학위수여년월 2017. 2
- 학위구분 석사
- 학과 의용과학대학원 의학물리학과
- 원문페이지 33 p
- 실제URI http://www.dcollection.net/handler/korea/000000071530
- 본문언어 영어
- 제출원본 000045897823
초록/요약
Purpose: To identify the independent factors associated with increased radiation dose and to evaluate the effect of a patient’s position on the effective dose for abdominal digital radiography. Materials and Methods: We retrospectively evaluated the effective dose for abdominal digital radiography in 222 patients in both supine and standing positions. The patients were divided into two groups with a cut-off value of 0.311mSv which is the upper third quartile of the dose distribution: Group A (n=166, effective dose < 0.311mSv); and Group B (n=56, effective dose ≥ 0.311mSv). Using logistic regression analysis, the independent factors associated with the increased effective dose were identified. The effect of a patient’s position on the effective dose was also evaluated using paired t-test. Results: In univariate analysis, a high body mass index (BMI) (≥ 23 kg/m2), presence of ascites, and spinal metallic instrumentation were significantly associated with an increased effective dose (p<0.001, p<0.001 and p=0.009, respectively). Multivariate logistic regression analysis revealed that a high BMI (odds ratio (OR), 25.201; 95% confidence interval (CI), 8.576-74.051; p < 0.001) and ascites (OR, 25.132; 95% CI, 5.381-117.376; p<0.001) were significantly associated with an increased effective dose. The effective dose was significantly decreased (22.6%) in supine position compared with that in standing position (p<0.001). Conclusion: High BMI and ascites were the independent factors associated with an increased effective dose in abdominal digital radiography. The significant dose reduction in patients with these factors may be achieved by the patient being placed in the supine position during abdominal digital radiography.
more목차
Ⅰ. Introduction 1
Ⅱ. Materials and Methods 2
1. Study design and patient population 2
2. Radiographic equipment and exposure parameters 4
3. Effective dose measurement and calculation 4
4. Definitions and statistical analysis of data 5
5. Comparison of the supine and standing effective doses 6
Ⅲ. Results
1. Exposure parameters and effective dose 7
2. Factors influencing the effective dose 12
3. Comparison of the supine and standing effective doses 13
Ⅳ. Discussion 14
References 17
Abstract 21
