Quality optimized medical image steganography based on edge detection and hamming code A Picture Archiving and Communication System (PACS) is a technology designed to store and transmit digitized medical images over a public network for certain uses. One of the main concerns relating to most of the existing systems is that little attention has been paid to the security and protection of patients’ information. Accordingly, there has been an increased interest in recent years to enhance the confidentiality of patients’ information. This paper introduces a high imperceptibility digital steganography method that hides Electronic Patient Records (EPR) into a medical image without modifying its important part. This method utilizes edge detection to identify and embed secret data in sharp regions of the image, as the human visual system (HVS) is less sensitive to changes in high contrast areas of images, compared to their smooth areas. Moreover, a Hamming code that embeds 3 secret message bits into 4 bits of the cover image is utilized as this will help in enhancing the quality of the produced images. We hide EPR into the Region of Non-Interest (RONI) to protect the decision area i.e., Region of Interest (ROI), which is essential for the diagnosis. The effectiveness of the proposed scheme is proven through the well-known of imperceptibility measure of Peak Signal-to-Noise Ratio (PSNR) when considering different message length.