Van Ongeval C, Jacobs J, Bosmans H
Department of Radiology, University Hospitals Leuven, Leuven, Belgium.
JBR-BTR. 2008 Nov-Dec;91(6):262-3.
In April 2005 screening with digital mammography was allowed in the Flemish part of Belgium. A rigorous physical-technical Quality Control (QC) procedure based on the European guidelines (EUREF) was then implemented. Besides quality control, there is also quality assurance (QA). Detection of artifacts is part of the QA. During the central second reading, a continuous evaluation of the image quality is done. All visible artifacts in the digital images are registered and collected. All systems participate also in a daily quality control, with a daily exposure of a phantom image which is sent to the certified quality control group. The collected artifacts were divided into 5 different categories: patient related artifacts, technologist related artifacts, mammography unit related artifacts, processing related artifacts and viewing conditions related artifacts. Patient related artifacts are comparable with film screen mammography (FSM) and are therefore not discussed. One of the main artifacts in the group of technologist related artifacts is dust in the cassette of computed radiography (CR) systems. In the group of mammography unit related artifacts a distinction is made between the artifacts of CR systems and direct radiography (DR) systems. In the CR group, the artifacts originate in the reader, whereas in the DR group they originate in the detector, which in our study was a Selenium detector. Artifacts due to failure of the Selenium detector are most frequent in this last group. Processing related artifacts are found when the reading of the processing algorithm by the system or by the PACS software made mistakes. Because there is a daily quality control of the monitors of the soft copy work stations, we didn't recognize viewing conditions related artifacts. Some of the artifacts can simulate breast lesions or can disturb the reading of the images. In order to avoid misinterpretation, recognizing artifacts and understanding their physical-technical background are of great importance in digital breast imaging.
2005年4月，比利时弗拉芒地区允许使用数字乳腺摄影进行筛查。随后实施了基于欧洲指南（EUREF）的严格物理技术质量控制（QC）程序。除了质量控制，还有质量保证（QA）。伪影检测是QA的一部分。在中央二次阅片期间，会对图像质量进行持续评估。数字图像中所有可见的伪影都会被记录和收集。所有系统也都参与每日质量控制，每天曝光一张体模图像并发送给经认证的质量控制小组。收集到的伪影被分为5个不同类别：与患者相关的伪影、与技术人员相关的伪影、与乳腺摄影设备相关的伪影、与处理相关的伪影以及与阅片条件相关的伪影。与患者相关的伪影与屏-片乳腺摄影（FSM）类似，因此不再讨论。与技术人员相关的伪影组中的主要伪影之一是计算机X线摄影（CR）系统暗盒中的灰尘。在与乳腺摄影设备相关的伪影组中，CR系统和直接数字化X线摄影（DR）系统的伪影有所不同。在CR组中，伪影源于读取器，而在DR组中，它们源于探测器，在我们的研究中探测器是硒探测器。硒探测器故障导致的伪影在最后一组中最为常见。当系统或PACS软件对处理算法的读取出现错误时，会出现与处理相关的伪影。由于对软拷贝工作站的显示器进行了每日质量控制，我们未识别出与阅片条件相关的伪影。一些伪影可能会模拟乳腺病变或干扰图像的读取。为避免误判，识别伪影并了解其物理技术背景在数字乳腺成像中非常重要。
