Prof. TIAN Chao’s group from the Department of Precision Machinery and Instrumentation, University of Science and Technology of China (USTC) has made progress on the photoacoustic imaging for medical science. They improved the imaging quality and 3D construction of the photoacoustic imaging, and applied them to in vivo sentinel lymph node imaging. The studies were published in IEEE Transactions on Biomedical Engineering, Physical Review Applied and Journal of Biophotonics.
Sentinel lymph node biopsy (SLN) is currently the standard method for breast cancer staging, which includes preoperative lymph node tracing and intraoperative lymph node biopsy image-guiding. However, existing image guidance techniques suffer from a variety of limitations, such as harmful ionizing radiation, high cost, and poor imaging depth.
To solve the problems, Prof. TIAN’s group proposed a contract-agent-enhanced photoacoustic imaging method, which used clinically-approved carbon nanoparticles as a contrast agent to trace SLN and guide fine needle aspiration biopsies, non-invasively and non-radioactively.
The researchers injected carbon nanoparticles (CNPs) into the forepaws of living rats to stain SLN. Subsequently, photoacoustic and ultrasound dual-modality imaging were performed simultaneously in real-time at the axillary area of the rats to trace the SLN and guide the biopsy.
In vivo photoacoustic SLN imaging using CNPs as the contrast agent. (a) Schematic representation of the drainage of CNPs into the SLN through forepaw injection and microscopic anatomy of a lymph node. (b) Principle of photoacoustic and ultrasound dual-modality imaging of the SLN and histological validation of the presence and biodistribution of CNPs in the SLN. (Image plotted by IEEE Xplore 2020)
Experiments showed that photoacoustics can image and display lymphatic vessel, lymph nodes, needles, etc. with high resolution and high signal-to-noise ratio, which can provide high-quality image guidance for lymph node biopsy.
In addition, spectroscopic analysis showed that CNPs are superior to indocyanine green, methylene blue and other contrast agents in optical absorption coefficient, photobleaching and photoacoustic conversion efficiency. It is an excellent tracer for identifying SLN by photoacoustic imaging and image-guided biopsies.
1. In Vivo Photoacoustic Sentinel Lymph Node Imaging Using Clinically-Approved Carbon Nanoparticles, https://ieeexplore.ieee.org/document/8902046 ;
2. Impact of System Factors on the Performance of Photoacoustic Tomography Scanners, https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.13.014001 ;
3. Three‐dimensional interventional photoacoustic imaging for biopsy needle guidance with a linear array transducer, https://onlinelibrary.wiley.com/doi/abs/10.1002/jbio.201900212 ;
4. Image-guided biopsies, https://www.chp.edu/our-services/radiology/patient-procedures/image-guided-biopsies .
(Written by ZHAO Xiaona, edited by JIANG Pengcen, USTC News Center)
On May 11, the Nature Publishing Group released Nature Publishing Index 2010 China, remarking “a dramatic rise in the quality of research being published by China”. University of Science and Technology of China is ranked 3rd of TOP 10 Institutions in Index 2010 China.
This article came from News Center of USTC.