This paper presents a region based blind medical image watermarking (MIW) scheme for ensuring authenticity, integrity and confidentiality of medical images. Medical image is segmented into region of interest(ROI) and region of non interest (RONI). ROI is watermarked for tamper detection and recovery in the spatial domain. For providing confidentiality and authenticity, electronic patient record (EPR) and hospitals logo is embedded as a robust watermark in RONI using IWT-SVD hybrid transform. Various experiments were carried out on different medical imaging modalities for performance evaluation of the proposed scheme in terms of imperceptibility, robustness, tamper detection and recovery. Evaluation results show that the visual quality of watermarked image is good and it is robust under common attacks. A comparison with well known schemes has been performed to show superiority of the proposed method.