Princivalli M, Stea L, Ordóñez P L, Bussoli L, Marchetti C
Servizio di Fisica Sanitaria, Ospedale Umberto I, Mestre, Venezia.
Radiol Med. 1995 May;89(5):667-74.
The authors report their personal experience with the use of an integrated quality control system in the radiology department. The system we used was the RTI DIGI-X Plus, a Swedish-made product, allowing a wide range of parameters to be measured on diagnostic X-ray units for general radiography, mammography and fluoroscopy. Data can be retrieved with a minimum number of measurements. The "oRTIgo" software improves the quality assurance system and ensures document compliance with international recommendations. The equipment consists of a detector unit, a processor and a display unit. The detector consists of a rotating holder with 12 combinations of metal filters of various thickness mounted in front of two photo-diodes covered with identical X-ray intensifying gadoliniumoxysulfide screens. This unit is connected to a data acquisition system controlled by a microcomputer. Peak tube voltage and total tube filtration are derived from the ratio of detector signals. The relationship between this ratio and the measured quantity is determined by a calibration procedure. Furthermore, exposure time "mAs" value, "mAs" linearity and exposure (or kerma in air) can be measured. Digital storage can be performed and input signals displayed. A serial interface is used to communicate with a PC for QC management purposes. An error propagation model is used to determine the inaccuracy of peak tube voltage measurements. With the DIGI-X Plus system, measurements can be carried out in a shorter time and the stored data reprocessed later on. After QA testing on 20 X-ray units in the radiology department, in vivo doses were measured using a TLD Harshaw 100 on 46 randomly selected patients undergoing chest examinations. The results are reported and analyzed following the NRPB protocol and show high agreement with the recommended values.
作者报告了他们在放射科使用综合质量控制系统的个人经验。我们使用的系统是瑞典制造的RTI DIGI-X Plus，它可以在普通放射摄影、乳腺摄影和荧光透视的诊断X射线设备上测量广泛的参数。只需进行最少次数的测量即可检索数据。“oRTIgo”软件改进了质量保证系统，并确保文档符合国际建议。该设备由一个探测器单元、一个处理器和一个显示单元组成。探测器由一个旋转支架组成，在两个覆盖有相同的X射线增强硫氧化钆屏的光电二极管前面安装了12种不同厚度的金属滤光片组合。该单元连接到由微型计算机控制的数据采集系统。管电压峰值和总管过滤是从探测器信号的比率得出的。该比率与测量量之间的关系通过校准程序确定。此外，可以测量曝光时间“mAs”值、“mAs”线性度和曝光量（或空气中的比释动能）。可以进行数字存储并显示输入信号。使用串行接口与个人计算机通信以进行质量控制管理。使用误差传播模型来确定管电压峰值测量的不准确性。使用DIGI-X Plus系统，可以在更短的时间内进行测量，并在以后对存储的数据进行重新处理。在对放射科的20台X射线设备进行质量保证测试后，使用TLD Harshaw 100对46名随机选择的接受胸部检查的患者进行了体内剂量测量。按照国家辐射防护委员会的方案报告并分析了结果，结果与推荐值高度一致。
