Medical imaging plays an important role in a patient's diagnosis, decision-making, and treatment; thus, any distortions in the medical image would not be tolerated, even the slightest ones. Furthermore, the imperative of safeguarding patients' private information with a reliable multimedia security technique is needed to ensure the fulfillment of the aforementioned issues. Hence, digital watermarking is considered one of the most reliable techniques for securing medical data. In this work, we present a new watermarking scheme based on Discrete Shearlet Transform (DST), and the Radon Transform (RT). The host medical image is transformed into the DST and the watermark is transformed into the RT and embedded into the low-frequency sub-band of the DST. Experimental results demonstrate high perpetual quality in terms of Peak Signal-to-noise ratio (PSNR), as the PSNR ranged from 65 dB to 72 dB across the entire utilized medical datasets. Finally, in terms of robustness, the Normalized Correlation (NC) value is well maintained above 0.9. Comparison results demonstrated that our proposed scheme outperformed other state-of-the-art works in terms of imperceptibility.