Securing medical images becomes a major concern to avoid leaking confidential data. This problem motivated the development of many low computational complexity methods to encrypt these medical images. In this research work, block cipher-based region of interest medical image encryption with multiple maps is proposed. Primarily, region of interest (ROI) regions and region of background (ROB) are extracted with the help of Laplacian edge detection operator. Further, important ROI regions are permuted in a circular fashion with the help of Arnold cat map and angle value. Then permuted ROI part is encrypted using the duffling system and unimportant regions are unchanged. The advantage of the work is that it encrypts only selected/important parts and that will achieve fast execution speed and reduction in computation complexity. The approach presented here enables the storage and transmission of medical image data within an open network. These results show that the security in the proposed method is much better than many chaotic encryption algorithms proposed in the recent times.