Wang, ‪Zhehui

Abstract Background X‐ray Induced Acoustic Computed Tomography (XACT) is an emerging imaging technique that provides 3D volumetric images from a single projection by detecting X‐ray‐induced acoustic (XA) waves with ultrasound (US) transducers. Unlike MRI or CT, XACT enables real‐time 3D imaging without long acquisition times, 2D limitations, or motion artifacts from mechanical rotation. Furthermore, when integrated with conventional pulse‐echo US through time‐sequenced operation, XACT provides complementary soft‐tissue contrast, establishing it as a promising platform for dynamic interventional radiology (IR) guidance. Purpose This study aims to evaluate the feasibility of XACT as a novel imaging tool for IR, specifically for guiding needle placement and monitoring contrast agent dynamics. Methods We developed a 3D XACT imaging system equipped with a 256‐element 2D matrix array and a portable X‐ray tube to visualize needle insertion and contrast agent dynamics. To capture both needle position and soft tissue anatomy, we integrated a dual‐modality system combining XACT with pulse‐echo US using a 128‐element linear US array. Experiments were conducted on both tissue‐mimic phantoms and soft tissue samples. GPU‐accelerated algorithm has been developed for 3D XACT image reconstruction. Results The results demonstrate the 3D capabilities of XACT imaging for interventional procedures, including monitoring of needle placement and tracking of contrast agent dynamics. The imaging speed reached up to 3∼4 s per frame, constrained by the repetition rate of the X‐ray source and signal to noise ratio. The dual‐modality approach provided clear visualization of the needle's position and the surrounding soft tissue structures, achieving imaging resolution around 2 mm. Conclusions This study demonstrates that XACT imaging is feasible to be used for IR. Its 3D imaging capability with faster imaging speed would be an alternative to cone beam CT and its capability to combine US imaging will provide richer information for soft tissue

Optical imaging is an ancient branch of imaging dating back to thousands of years. Radiographic imaging and tomography (RadIT), including the first use of X-rays by Wilhelm Röntgen, and then, γ -rays, energetic charged particles, neutrons, etc. are about 130 years young. The synergies between optical and radiographic imaging can be cast in the framework of these building blocks: Physics, Sources, Detectors, Methods , and Data Science , as described in Appl. Opt. 61 , RDS1 ( 2022 ) APOPAI 0003-6935 10.1364/AO.455628 . Optical imaging has expanded to include three-dimensional (3D) tomography (including holography), due in to part the invention of optical (including infrared) lasers. RadIT are intrinsically 3D because of the penetrating power of ionizing radiation. Both optical imaging and tomography (OIT) and RadIT are evolving into even higher dimensional regimes, such as time-resolved tomography (4D) and temporarily and spectroscopically resolved tomography (4D + ). Further advances in OIT and RadIT will continue to be driven by desires for higher information yield, higher resolutions, and higher probability models with reduced uncertainties. Synergies in quantum physics, laser-driven sources, low-cost detectors, data-driven methods, automated processing of data, and artificially intelligent data acquisition protocols will be beneficial to both branches of imaging in many applications. These topics, along with an overview of the Radiography, Applied Optics, and Data Science virtual feature issue, are discussed here.