Whole cross-sectional human ultrasound tomography

Ultrasonography is a vital component of modern clinical care, with handheld probes routinely used for diagnostic imaging and procedural guidance. However, handheld ultrasound imaging is limited by factors such as the partial cross-sectional field of view, operator dependency, contact-induced distortion and lack of transmission contrast. Here we demonstrate a new system that enables whole cross-sectional ultrasound tomography of humans in both reflection and transmission modes. We generate two-dimensional images of the entire in vivo human cross-section in the abdomen and thighs with uniform in-plane resolution using a custom 512-element circular ultrasound receiver array and a rotating transmitter. Sequential scans with our system show strong agreement with clinical magnetic resonance imaging counterparts. To address unmet clinical needs, we explore two key applications. First, we observe abdominal adipose distributions in our images, enabling adipose thickness assessment without ionising radiation or mechanical deformation. Second, we demonstrate an approach for video-rate biopsy needle localization with respect to internal tissue features. These capabilities make whole cross-sectional ultrasound tomography a potential practical tool for clinical needs currently unmet by other modalities.