As a result of internet expansion, the popularity of sharing medical documents between specialists in different medical institutes and hospitals has increased. Accordingly, protecting the transmitted patient's data against any modification or accessing from unauthorized people is a must. One of the popular solutions for protecting patient's data against tampers like copy-past, text addition and content removal and various geometric attacks like crop, rotate and resize and signal attacks like histogram equalization, Gaussian noise, median filter, and sharpening is watermarking techniques. Watermarking techniques can be classified according to many perspectives like Robustness, Human Perceptivity, Task Performed, Domain Type, Extraction Process and Secret Keys. Medical image can be in the spatial domain and transform domain. This paper presents a review of recent watermarking techniques of medical images and a comparison between various types of transform domains and the different purposes of medical images' watermark. A proposed scheme is presented in this paper.