胸腔與腹部數位X光攝影之影像品質與輻射劑量最佳化評估

Optimization of image quality and radiation dose for chest and abdomen radiography

黃嘉珮(Jia-Pei Huang)

指導教授 ： 陳拓榮

中山醫學大學/醫學科技學院/生物醫學科學學系碩士班/碩士(2013年)

https://doi.org/10.6834/CSMU.2013.00027

摘要

根據資料統計，胸腔和腹部X光攝影為常規X光攝影最常使用的檢查項目。根據行政院衛生署國民健康局統計，肺部和心臟疾病位居台灣國人十大死因之一。胸腔X光檢查為為早期診斷肺部或心臟是否有病變的診斷工具之一。腹部X光攝影可觀察腹部器官的大小、位置變化，提供了許多重要的腹部疾病的診斷訊息。
本研究目的評估胸腔和腹部X光攝影，其影像品質與輻射劑量之最佳化。首先，根據我們所收集的臨床資料，利用BMI去定義不同體型(瘦體型、正常體型、胖體型)，並設計不同曝射條件。我們開啟自動暴露控制 (automatic exposure control, AEC)系統，使用壓克力搭配影像品質假體模擬人體厚度。在影像品質部分，評估兩種影像品質假體，透過影像處理軟體分析影像。在輻射劑量部分，以蒙地卡羅模擬軟體計算使用不同曝射條件之輻射劑量，並以擬人形假體填入熱發光劑量計 (TLD)，評估人體實際接受曝射之輻射劑量。品質因數 (figure of merit, FOM)為影像品質分數的倒數 (inverse of image quality figure, IQFinv)的平方除以每次曝射之有效劑量，計算品質因數探討胸腔和腹部X光攝影，針對不同體型的受檢者，比較在不同曝射條件下的影像品質和輻射劑量，找出接受胸腔或腹部X光攝影，能根據受檢者體型使用之最佳曝射條件。

關鍵字

胸腔 ； 腹部 ； 影像品質 ； 劑量 ； FOM

並列摘要

The chest and abdominal radiography are the most commonly performed diagnostic X-ray examination from statistics. The lung and heart disease among the people of Taiwan one of the top ten causes of death, from the Bureau of Health Statistics. The chest X-ray examination is an early diagnostic tool for lung or heart disease. The abdominal X-rays can be observed in abdominal organ size, location, and provides much important diagnostic information.

This study investigates the chest and abdominal X-rays to assess the optimization of the image quality and radiation dose. First, we will collect clinical data, BMI was used to define different size (lean, normal, obese body), and the design of different radiation exposure parameters. Different thickness of acrylic was exposure by the automatic exposure control (AEC) system to simulate the human body from the current-time product. To analyze image quality, we used two image plates to evaluate the image quality score by commercial software. And, we evaluated the effective dose of different exposure condition by the simulation of Monte Carlo software (PCXMC) and the experiment of Rando phantom filled with thermoluminescent dosimeter (TLD). The figure of merit (FOM) for optimization is defined as the inverse of image quality figure (IQFinv) square per effective dose. We analyzed the FOM of the chest and abdomen X-ray images and doses in different exposure parameters with three different sizes. By the FOM comparison to find the optimization of exposure parameter in different body size patients for chest and abdomen radiography.

並列關鍵字

chest ； abdomen ； image quality ； dose ； FOM

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