PERFORMANCE MEASUREMENT OF MEDICAL IMAGING SYSTEMS BASED ON MUTUAL INFORMATION METRIC

Information on physical image quality of medical images is important for imaging system assessment in order to promote and stimulate the development of state- of-the-art imaging systems. In this paper, we present a method for measuring physical performance of medical imaging systems. In this method, mutual information (MI) which is a concept from information theory was used to measure combined properties of image noise and resolution of an imaging system. In our study, the MI was used as a measure to express the amount of information that an output image contains about an input object. The more the MI value provides, the better the image quality is. To validate the proposed method, computer simulations were first performed to investigate the effects of noise and resolution degradation on the MI. Then experiments were conducted to measure the physical performance of an imaging plate which was used as an image detector. Our simulation and experimental results confirmed that the combined effect of deteriorated blur and noise on the images can be measured and analyzed using the MI metric. The results demonstrate the potential usefulness of the proposed method for measuring physical quality of medical imaging systems.