Approaching closed spherical, full-view detection for photoacoustic tomography

Abstract

. Significance: Photoacoustic tomography (PAT) is a widely explored imaging modality and has excellent potential for clinical applications. On the acoustic detection side, limited-view angle and limited-bandwidth are common key issues in PAT systems that result in unwanted artifacts. While analytical and simulation studies of limited-view artifacts are fairly extensive, experimental setups capable of comparing limited-view to an ideal full-view case are lacking. Aims: A custom ring-shaped detector array was assembled and mounted to a 6-axis robot, then rotated and translated to achieve up to steradian view angle coverage of an imaged object. Approach: Minimization of negativity artifacts and phantom imaging were used to optimize the system, followed by demonstrative imaging of a star contrast phantom, a synthetic breast tumor specimen phantom, and a vascular phantom. Results: Optimization of the angular/rotation scans found effective detectors were needed for high-quality images, while 15-mm steps were used to increase the field of view as required depending on the size of the imaged object. Example phantoms were clearly imaged with all discerning features visible and minimal artifacts. Conclusions: A near full-view closed spherical system has been developed, paving the way for future work demonstrating experimentally the significant advantages of using a full-view PAT setup.

PATLAB: A graphical computational software package for photoacoustic computed tomography research

“…Next, we used PATLAB to process and reconstruct experimental data collected with a PAT system available in our laboratory [14] . The PAT system provided near full view 3D PAT imaging of objects.…”

Investigating the feasibility of a hand-held photoacoustic imaging probe for margin assessment during breast conserving surgery

“…The phantom was imaged with the hand-held PAI probe, then flipped 180° to acquire information from the opposite side. Next, the phantom was imaged using a near full view photoacoustic tomography (PAT) system, reported elsewhere [47] . Briefly, the near full view system was comprised of eight illumination fibres and 64 PVDF-based unfocused detectors (circular apertures of 12.7 mm) divided into 16 modules (Superior Assemblies, Mississauga, ON, CA).…”

Investigating the feasibility of a hand-held photoacoustic imaging probe for margin assessment during breast conserving surgery

“…Multiple dots were placed on the bag using a permanent black marker as landmarks for image registration. The phantom was imaged with the hand-held probe and a custom near-full view photoacoustic tomography (PAT) system, reported elsewhere [24], to assess the effects posed by the limited angular covered achievable with the hand-held PAI probe.…”