Software Tools Dedicated for an Automatic Analysis of the CT Scanner Quality Control’s Images

This paper deals with the CT scanner images quality control, which is an important part of the quality control process of the CT scanner, which consists of making measurement in images of dedicated phantoms. Standard methods consist of scan explorations of phantoms that contain different specific patterns . These methods rely on manual measurements with graphics tools in corresponding images (density, position, length...) or automatic measurements developed in softwares 4 that use some masks to determine the region of interest (ROI). The problem of these masks is that they may produce wrong results in case of misalignment of the phantom. We propose a new method that consists, firstly of developing software tools that are capable of performing an automated analysis of CT images of three standard phantoms, LAP , GEMS and CATPHAN600, in terms of slice thickness, spatial resolution, low and high level contrast, noise and uniformity. The method we have developed is completely automatic because it uses some protocols and special treatments in the images to automatically detect the position and the size of the ROI. Secondly, to test the performances of our software tools, we develop two digital phantoms which reproduce the exact geometry and composition of the physical phantoms, i.e. some perfect CT images of the real phantoms, and a complete set of distorted digital phantoms which represent the “perfect” phantom distorted by noise and blur calibrated functions to test the performances of our automated analysis software.