- 學位論文
探討自動曝露控制技術於模擬不同厚度腹部假體之應用
Explore the Application with Automatic Exposure Control Technology in Simulating Different Abdomen Phantom
摘要
本研究主要探討自動曝露控制(AEC)應用在肥胖病人的腹部攝影時，厚度與管電壓之間曝露因子的變化關係，產生的輻射劑量是否適當，得出AEC應用於肥胖病人時的使用建議。使用Philips diagnost TH X光機、Hologic DPA/QDR-1 Anthropomorphic Spine Phantom與自製水假體，得到在81kVp、85kVp、90kVp、96kVp與102kVp管電壓條件下與各種厚度水假體產生之曝露因子數值，討論AEC使用於肥胖病人時之穩定性。以上述實驗獲得之曝露因子數值，計算不同假體厚度於不同管電壓條件下曝露三次後產生之曝露因子數值的平均值，以SPSS統計軟體進行迴歸分析。將腰椎假體置入水假體，以各編組之條件進行AEC攝影並儲存影像作為對照組。根據對照組影像條件，手動調整成較低之曝露因子條件，進行攝影並儲存影像作為實驗組。請兩名醫事放射師作為受試對象，於雙螢幕工作站隨機顯示實驗組與對照組之腰椎影像，評估影像能否區分優劣，若能區分優劣，指出較佳影像。記錄數據後執行Cohen's kappa一致性分析。結果為AEC適合使用在厚度36cm以上之肥胖病人且應用管電壓條件為102kVp之腹部攝影。
並列摘要
This study investigated the relationship between the exposure of thickness and tube voltage. To evaluate the radiation dose appropriation for the automatic exposure control (AEC) in abdominal radiography of obese patients. The values of the exposure factors generated with various thicknesses of water phantom at 81 kVp, 85 kVp, 90 kVp, 96 kVp, and 102 kVp tube voltage were obtained by using the Phlips diagnost TH X-ray machine, the Hologic DPA/QDR-1 Anthropomorphic Spine Phantom and the self-made water phantom. Exposure dose of different phantom thicknesses under different tube voltage conditions were calculated based on the exposure factor values obtained in the above experiments. The lumbar vertebral phantom was placed in the water phantom, AEC radiography was performed on each grouping condition and the images were stored as a control group. According to the image conditions of the control group, a lower exposure factor level was used to exposure and then save the image as an experimental group. Randomly display lumbar images with the experimental group and the control group on a dual screen in the workstation the images could be distinguished that determine distinguished by 2 radiographers. Perform Cohen's kappa consistency analysis after recording the data. The result showed that AEC is suitable for thickness of 36 cm or more obese patients with a tube voltage of 102 kVp during abdomen radiography examination.