Airs-Net: Adversarial-improved reversible steganography network for CT images in the Internet of Medical Things and telemedicine

Medical imaging has developed from an auxiliary means of clinical examination into a significant method and intuitive basis for clinical diagnosis of diseases, providing all-around and full-cycle health protection for the people. The Internet of Medical Things (IoMT) allows medical equipment, intelligent terminals, medical infrastructure, and other elements of medical production to be interconnected, eliminating information silos and data fragmentation. Medical images disseminated in IoMT contain a wide diversity of sensitive patient information, which means protecting the patient's personal information is vital. In this work, an Adversarial-improved reversible steganography network (Airs-Net) for computed tomography (CT) images in the IoMT is presented. Specifically, the Airs-Net adopting the prediction-embedding strategy mainly consists of an image restoration network, an embedded pixel location network, and a discriminator. The image restoration network is effective in restoring the pixel prediction error of the restoration set in integer and non-integer scaled images of arbitrary size when information is concealed. The embedded information location network can automatically select pixel locations for information embedding based on the interpolated image features of the degraded image. The restored image, embedding location map, and embedding information are fed into the embedder for information embedding, and the subsequent secret-carrying image is continuously optimized for the quality of the information-embedded image by the discriminator. Quantitative results show that Airs-Net outperforms state-of-the-art methods in both PSNR and SSIM. Further, the qualitative and quantitative results and analyses under specific clinical application scenarios and in coping with multiple types of medical image information hiding demonstrate the excellent generalization performance and practical application capability of the Airs-Net.