High-precision 3D spatial localization for limited-view artifact mitigation in freehand photoacoustic computed tomography

Photoacoustic computed tomography (PACT) is an emerging medical imaging modality that has attracted considerable interest for its potential clinical application. However, the limited angular coverage of ultrasound transducers impedes the acquisition of omnidirectionally emitted photoacoustic signals from the target, resulting in incomplete reconstruction of imaging targets. To address this challenge, a freehand PACT imaging framework utilizing high-precision three-dimensional (3D) spatial localization is presented. Precise tracking of the spatial coordinates of the ultrasound transducer enables multi-angle photoacoustic signal acquisition. Through the fusion of multi-angle PA signals, the proposed method can build accurate PACT images with little limited-view artifacts. Validation experiments using phantoms of varying geometries demonstrate effectiveness in suppressing limited-view effects. This methodology can be readily integrated into clinical PACT systems to improve image accuracy and advance the clinical translation of PACT technology.