Quality Assurance Supporting System for Digital X-ray Image Utilizing Filing System of DICOM-3.0

为保证数字X线图像的质量，开发了一套质量控制系统。该系统将以最少的人力和成本支持QC流程。主要研究结果如下：1）利用CR系统测量输出X射线强度、半值层（HVL）和管电位将口内X射线成像板（IP）插入个人剂量计的胶片徽章盒中，测量窗口上有铝、铜和锡制成的滤光片。该系统测量输出X射线强度的误差为± 5%，HVL的误差为± 0.17mm，管电位的误差为± 2%。2）IP衰减的评价方法IP通过X射线均匀辐射并扫描。开发了数字图像处理软件，实现了划痕噪声的二值化。3）质量保证支持信息系统的开发基于DICOM标准的质量保证支持信息系统。通过对质量控制相关设备和物料的面向对象分析，确定了信息对象的结构以及服务器和客户端的性能。因此，该规范不仅适用于牙科X线摄影，而且适用于放射学中使用的所有模态。

A quality control (QC) system for the quality assurance (QA) of digital x-ray image was developed. The system would support the QC procedures with the least labor of staff and cost. The main outcomes of the development were as follows.1)Measurement of output x-ray intensity, half value layer (HVL) and tube potential utilizing computed radiography(CR) systemAn imaging plate (IP) for intraoral radiography was inserted into a film badge case for personal dosimeter with filters made of aluminum, copper and tin on the measuring windows. This system could measure the output x-ray intensity with an error of ±5%, the HVL with an error of ±0.17mm and the tube potential with an error of ±2%.2)Method for evaluation of IP's degradationA method for the detection of the scratch noise of IP for intraoral radiography was developed. An IP was uniformly radiated by x-rays and scanned. A digital image processing software was developed to get a binary image of the scratch noise.3)Development of QA supporting information systemA QA supporting information system based on DICOM standard was developed. Based on the object oriented analysis of devices and materials concerning QC, the structure of the information objects and performance of the servers and clients were defined. As a result, the specification was applicable not only to dental radiography but also to all the modality used in radiology.