Metrology applications of quantitative evaluation methods in CT phantom images

As a common CT image quality (IQ) test phantom, Catphan500 is widely used for the verification tests in Chinese metrology institutes as well as hospital routine quality assurance (QA). Although the National Verification Regulation of Medical Diagnostic X-ray Radiation Source for Spiral CT (JJG 1026-2007) had been issued and carried out for years in China, however, main parameters such as image uniformity, CT number, high spiral resolution, and low contrast resolution, were obtained totally by manual methods and then analyzed with qualitative evaluation procedures. In this paper, a fully automated program mode for the calibration of Catphan500 phantom images was developed, which was quantitative and time-efficient. The aim of this study is to initially realize the transition from the manual methods with qualitative evaluation to the automatic methods with quantitative evaluation, and to improve work efficiency as well.