Speckle is a fundamental property of all coherent imaging systems. It reduces contrast resolution and thereby the detectability of low contrast lesions. Speckle is also perceived as a significant distraction and impediment for new applications of ultrasound imaging. TETRAD has demonstrated that a non-linear, iterative algorithm can effectively reduce speckle in ultrasound images without significant loss of detail. Such a development could potentially improve the diagnostic value of ultrasound for expert viewers and would ease image interpretation for the non-expert. The proposed work has three goals: 1) to adapt this algorithm to the special requirements imposed by ultrasound imaging (e.g., non-uniform spatial resolution, high dynamic range, etc.); 2) to design a hardware architecture suitable for real-time speckle reduction; and 3) to clinically demonstrate the effectiveness of this method for improving the probability of detecting low contrast, focal lesions. Two major application areas will be investigated: 1) intraoperative/laparoscopic scanning of the liver and 2) breast screening. Imaging will be performed using high frequency (7.5-12 MHz), high resolution systems. The proposed project is a collaborative effort between hardware designers, algorithm developers, and end-users in radiology and surgery.