Coherence-Based Fetal Ultrasonic Imaging

Abstract Ultrasonic imaging is widely used to monitor fetal growth and development during the first and second trimester, and multiple studies document the resultant positive impacts on fetal and maternal outcomes. However, current methods fail to provide adequate visualization of key structures in many patients, and alternative imaging modes are rarely available to these patients. We have developed novel ultrasonic beamforming methods that utilize the spatial coherence of backscattered echoes. These methods, in simulation, phantom, and blinded-observer clinical studies, show markedly improved image quality over conventional ultrasonic images, especially in difficult-to-image patients. We propose extend our theory of coherence imaging to 1.5D and 2D arrays and to very large arrays. Using such advanced arrays, we propose clinical studies to assess the role of coherence imaging in key fetal diagnostic tasks in first trimester and second trimester scans. Quantitative image quality metrics and observer studies are proposed to compare B-mode and coherence images with an emphasis on difficult-to-image patients for whom current imaging methods fail. Related studies will measure the contribution of various sources of image degradation in fetal scans. If successful, the proposed research could lead to a new class of ultrasonic beamforming methods that operate in imaging environments in which current methods fail.