電腦斷層掃描儀影像品質控管

Computed Tomography Image Quality Control

10.30173/JG.201206.0003

張榮華(Jung-Hua Chang)；施宛庭(Wan-Ting Shih)；秦作威(Trow-Way Chin)

電腦斷層掃描儀 ； 水假體準確性 ； 高對比空間解析度 ； 低對比偵測度 ； computed tomography scanner ； water phantom accuracy ； high-contrast spatial resolution ； low contrast detectability

加馬

43期（2012 / 06 / 01）

19 - 28

繁體中文

電腦斷層掃描儀（Computed tomography, CT）的應用已是醫學影像的主流，並廣泛用於一般及特殊檢查中，為了確保斷層掃描的影像品質，必需進行有效的醫療曝露品保。本研究的目的為評估不同的電腦斷層掃數的數位X光影像系統，以ACR CT-464假體來分別來分析、量測兩種電腦斷層掃描儀影像系統。研究中將量測水假體準確性，高對比空間解析度，低對比偵測度，CT值中空氣、聚乙烯、水、壓克力、骨頭的影像分析資料，如此將可幫助醫療部門及放射師們了解目前所使用的電腦斷層掃描儀影像品質的狀況。結果顯示：用以上之方法，測得兩家醫院之數值，並對照輻射醫療曝露品質保證標準部分條文之診斷用電腦斷層掃描儀的校驗項目，除低對比偵測度兩家醫院皆超過標準值（A超過3mm，B超過1mm）及CT值部分有一組的空氣與水的值有些差異，其它數值均符合標準。

Application of the CT scanner (Computed tomography to, CT) is the mainstream of medical imaging, and is widely used for general and special inspections. In order to ensure the image quality of CT scan, it is necessary to carry out the medical exposure quality assurance. The purpose of this study is to evaluate the different computed tomography scan number of digital X-ray imaging system by analyzing the ACR CT-464 prosthesis and measuring two kinds of computer tomography imaging system. In this study, we measured water prosthesis accuracy, high-contrast spatial resolution, low contrast detection degree, and image analysis of information in CT value of air, polyethylene, water, acrylic, and bone. It will help in the understanding of health departments and radiology masters about the currently used computer tomography instrument and the status of the image quality. The results showed that, using the above method, the values of two hospitals were measured and compared with the partial content of radiation medical exposure quality assurance standard for examination of diagnostic computed tomography scanner. Except the low-contrast detectability, in which the values of the two hospitals were exceeding the standard value (exceeding 3 mm and 1 mm at A and B hospitals, respectively) and some differences in part of the CT values of a group of air and water, the other values are in line with the standard.