Design and application of multiparameters contrast detail phantom using cylindrical double hole acrylic block for radiographic quality control tool

Abstract

The consistency of contrast detail performance of imaging system can be evaluated by using Contrast Detail phantom. The analysis is always based on the human visual perception which leads to intraobserver perception bias. In addition, the wall of single drilled hole concept in commercial Contrast Detail phantom gives effect to the penetration of x -ray beam divergence to pass through the base of each hole. This effect will lead to false appearance of image but it is not visualised in the radiograph. In this study, cylindrical double hole acrylic block of Multiparameters Contrast Detail phantom has been developed which differs from the single drilled hole concept, whereby it consists of combination of different holes’ diameters and thicknesses. Results revealed that, the new design of cylindrical double hole acrylic block is able to visualise the effect of image displacement from the x-ray focal length plus measuring the off-position of anode stem, blurring effect, image distortion in terms of real shape and size, also addressing the contrast detail characteristics parameter in terms of real hole depth. The influencing factors of source-image-distance, object thickness, position of object from center beam in x-axis, sizes of hole diameter and hole depth contribute to the changes in parameters’ outcome. The measurement of pixel intensity by using software and development of algorithm for data analysis basically can reduce the human perception bias and increase the validity of the results.