Linear array-based real-time photoacoustic imaging system with a compact coaxial excitation handheld probe for noninvasive sentinel lymph node mapping

Abstract

We developed a linear ultrasound array-based real-time photoacoustic imaging system with a compact coaxial excitation handheld photoacoustic imaging probe for guiding sentinel lymph node (SLN) needle biopsy. Compared with previous studies, our system and probe have the following advantages: (1) the imaging probe is quite compact and user-friendly; (2) laser illumination and ultrasonic detection are achieved coaxially, enabling high signal-to-noise ratio; and (3) GPU-based image reconstruction enables real-time imaging and displaying at a frame rate of 20 Hz. With the system and probe, clear visualization of the SLN at the depth of 2 cm (~human SLN depth) was demonstrated on a living rat. A fine needle was pushed towards the SLN based on the guidance of real-time photoacoustic imaging. The proposed photoacoustic imaging system and probe was shown to have great potential to be used in clinics for guiding SLN needle biopsy, which may reduce the high morbidity rate related to the current gold standard clinical SLN biopsy procedure.

Through Scalp and Skull NIR‐II Photothermal Therapy of Deep Orthotopic Brain Tumors with Precise Photoacoustic Imaging Guidance

“…The basic photophysical properties and laser penetration capability through scalp and skull were examined. The c‐RGD decorated NPs were systematically evaluated in PA imaging using a real‐time photoacoustic imaging system and PTT in vitro and in vivo, respectively …”

Technetium-Radiolabeled Mannose-Functionalized Gold Nanoparticles as Nanoprobes for Sentinel Lymph Node Detection

“…A significant difference observed between both agents was the minimal irritation induced by AuNPs-MAN 48 at the injection site compared with the sulfur colloid, which is a common side effect reported in the clinic. Another advantage of mannose-functionalized AuNPs is their potential use for multimodal photoacoustic SLN mapping, where binding to specific macrophage receptors is needed in order improve the specificity of the method [23,24]. Here, the use of mannose molecules for active targeting of the lymph node could increase the high affinity of the macrophage mannose receptor (MR, CD206), which is a C-type lectin predominantly expressed by most tissue macrophages, dendritic cells, and specific lymphatic or endothelial cells [25].…”

Parallel Computing for Quantitative Blood Flow Imaging in Photoacoustic Microscopy

“…Parallel computing based on GPU is proven effective to improve computational efficiency and is extensively adopted in PAT imaging systems, for which the image reconstruction algorithm is usually designed with a high computation complexity to obtain a better image quality [19][20][21][22][23]. In PAM system, GPU has been applied for the real-time structure imaging (MAP) of blood vessels in a mouse's ear [24,25].…”

“…Computer unified device architecture (CUDA) for NVIDIA GPU facilitates the programming and makes GPU one of the most popular acceleration hardware. With these advantages, GPU has been widely adopted to accelerate computation in photoacoustic imaging system, especially in PAT [19][20][21][22][23] for which the image reconstruction algorithm is much more complicated than PAM and needs high performance computation. Currently, several parallel computing methods with GPU have been implemented to reconstruct images in PAT systems such as back-projection (BP)-based PAT [19], finite element method (FEM)-based time-domain quantitative PAT [21] and double-state delay-multiply-and-sum (DS-DMAS)-based PAT [23].…”