Application of stochastic resonance for imaging enhancement of computed tomography in hepatocellular carcinoma

Contrast-enhanced computed tomography (CT) played an important role in detection of hepatocellular carcinoma (HCC). However, it´s contraindication to use contrast media in patients with some comorbidities. In this study, an approach for enhancement of CT images of HCC utilizing stochastic resonance (SR), a transform based method, is introduced. A series of CT images of HCC were obtained. The non-contrast-enhanced images were processed by SR. According to the results of applications of SR, it significantly increases the signal-to-noise ratio and enhances the degree of order in a system with appropriate tuning of the noise intensity and adjusting of the threshold. In this application of CT image enhancement, SR uses the ubiquitous random perturbations of noise with appropriate intensity to emphasize the gray- level range of interest. HCC was well visualized on SR enhanced images. Furthermore, a measure of image enhancement related with concepts of the Webers Low of the human visual system was applied to quantify the enhancement contributed by SR. The values of measure of enhancement or measure of improvement (EME) for the original CT images performed mean and standard deviation of 2.615 + 2.147, and 6.257 + 1.189 for the enhanced CT images.