▪ Abstract Since the introduction of medical ultrasound in the 1950s, modern diagnostic ultrasound has progressed to see many major diagnostic tools come into widespread clinical use, such as B-mode imaging, color-flow imaging, and spectral Doppler. New applications, such as panoramic imaging, three-dimensional imaging, and quantitative imaging, are now beginning to be offered on some commercial ultrasound machines and are expected to grow in popularity. In this review, we focus on the various algorithms, their processing requirements, and the challenges of these ultrasound modes. Whereas the older, mature B and color-flow modes could be systolically implemented using hardwired components and boards, new applications, such as three-dimensional imaging and image feature extraction, are being implemented more by using programmable processors. This trend toward programmable ultrasound machines will continue, because the programmable approach offers the advantages of quick implementation of new applications without any additional hardware and the flexibility to adapt to the changing requirements of these dynamic new applications. Source.