Photoacoustic imaging is a promising medical imaging technique that provides excellent function imaging of an underlying biological tissue or organ. However, it is limited in providing structural information compared to other imaging modalities, such as ultrasound imaging. Thus, to offer complete morphological details of biological tissues, photoacoustic imaging is typically integrated with ultrasound imaging. This dual-modal imaging technique is already implemented on commercial clinical ultrasound imaging platforms. However, commercial platforms suffer from limited elevation resolution compared to the lateral and axial resolution. We have successfully developed a dual-modal photoacoustic and ultrasound imaging to address these limitations, specifically targeting animal studies. The system can acquire whole-body images of mice in vivo and provide complementary structural and functional information of biological tissue information simultaneously. The color-coded depth information can be readily obtained in photoacoustic images using complementary information from ultrasound images. The system can be used for several biomedical applications, including drug delivery, biodistribution assessment, and agent testing.

Breast cancer screening with mammography is less effective in women with dense breast tissue, prompting the use of ultrasound (US) imaging. While two- (2D) and three-dimensional (3D) US improve cancer detection, their low specificity leads to frequent unnecessary biopsies. Operator dependence on 2D US has led to the development of 3D automated breast volume scanners (ABVS), but challenges remain in distinguishing benign from malignant lesions. We developed a 3D photoacoustic and ultrasound (PAUS)–ABVS system that integrates a large field-of-view, 768-element transducer to improve diagnostic accuracy. In a clinical study of 61 patients with 36 benign and 30 malignant lesions, multispectral photoacoustic imaging was used to measure blood volume and oxygen saturation within lesions. When combined with standard US BI-RADS (breast imaging reporting and data system) scores, the system achieved a sensitivity of 96.7% and specificity of 66.7%. This performance matched the best outcomes of 2D PAUS and outperformed conventional US. Our results suggest that the PAUS-ABVS can support more accurate breast cancer diagnosis while reducing unnecessary biopsies.

X-ray-induced acoustic computed tomography (XACT) has shown great potential as a hybrid imaging modality for real-time non-invasive x-ray dosimetry and low-dose three-dimensional (3D) imaging. While promising, one drawback of the XACT system is the underlying low signal-to-noise ratio (SNR), limiting its in vivo clinical use. In this Letter, we propose the first use of a conventional x-ray computed tomography contrast agent, Gastrografin, for improving the SNR of in situ XACT imaging. We obtained 3D volumetric XACT images of a mouse's stomach with orally injected Gastrografin establishing the proposal's feasibility. Thus, we believe, in the future, our proposed technique will allow in vivo imaging and expand or complement conventional x-ray modalities, such as radiotherapy and accelerators.

Large field‐of‐view (FOV) photoacoustic‐ultrasound (PA/US) imaging provides a powerful framework for volumetric visualization of vascular and structural features, yet its broader adoption has been constrained by channel scalability and system complexity. We present a scalable three‐dimensional (3D) PA/US imaging architecture that integrates a commercial 768‐element linear array with programmable digital multiplexing (MUX) to enable large‐FOV volumetric acquisition without proportional increases in hardware burden. A field‐programmable gate array (FPGA)‐based MUX scheme enables sequential activation of contiguous sub‐apertures while preserving imaging sensitivity and spatial resolution, effectively decoupling aperture size from host system channel count. The resulting system supports volumetric imaging of extended anatomical regions within a single volumetric scan. The capabilities of the proposed approach are demonstrated through in vivo imaging of multiple human extremity regions, including the palm, dorsum of the hand, the forearm, and the foot, which serve as representative testbeds for large ‐FOV imaging geometries. PA imaging reveals detailed vascular structures, and multispectral acquisition enables estimation of blood oxygen saturation, providing functional contrast complementary to co‐registered US anatomy. Compared to conventional handheld PA/US probes, the large‐FOV configuration increases anatomical coverage per scan and avoids the need for multiple scans and stitching. These results establish digitally multiplexed, high‐element‐count PA/US imaging as a generalizable and extensible strategy for large‐FOV, anatomically and functionally informative volumetric imaging.