Multi-wavelength photoacoustic imaging (PAI) has garnered significant attention due to its excellent capabilities in molecular and functional imaging. Researchers in the PAI community are consistently in need of reliable multi-wavelength imaging platforms. For clinical applications, PAI machines that are mobile, compact, and rapidly tunable are required. We have designed a stable and cost-effective PAI platform which consists of an optical parametric oscillator (OPO), a data acquisition system (DAQ), and various imaging probes. The stability of the OPO has been enhanced through the implementation of air-floating springs and mirror frame designs, alongside open-loop wavelength control. Effective monitoring of energy using built-in energy meters has improved the accuracy of PA spectral measurements. Integration with digital boards has effectively enhanced the noise resistance of DAQ and reduced its physical size. The platform can achieve a repetition rate of 10 Hz, swift wavelength tuning within the range of 680 to 950 nm (with a resolution of 1nm), and single-pulse energy greater than 80 mJ. The spectral range covers the absorption features of important chromophores such as hemoglobin, fat, and indocyanine green. The DAQ system can record PA data with 80 MHz sampling rate, 14-bit resolution, and 128/256/512 channels. The platform is equipped with linear array probes and semi-circular array probes to meet the requirements of both animal and human imaging. The semi-circular array probe utilizes a polydimethylsiloxane (PDMS) membrane with good light transmission to form a water bag for ultrasound coupling. This membrane is flexible and can conform well to different tissue shapes. Using this platform, we have conducted experiments including blood oxygen measurement, imaging of arm muscles and fat. In these experiments, we demonstrated accurate blood oxygen analyses and high-contrast muscle and fat imaging.
SignificanceTo ensure precise tumor localization and subsequent pathological examination, a metal marker clip (MC) is placed within the tumor or lymph node prior to neoadjuvant chemotherapy for breast cancer. However, as tumors decrease in size following treatment, detecting the MC using ultrasound imaging becomes challenging in some patients. Consequently, a mammogram is often required to pinpoint the MC, resulting in additional radiation exposure, time expenditure, and increased costs. Dual-modality imaging, combining photoacoustic (PA) and ultrasound (US), offers a promising solution to this issue.AimOur objective is to localize the MC without radiation exposure using PA/US dual-modality imaging.ApproachA PA/US dual-modality imaging system was developed. Utilizing this system, both phantom and clinical experiments were conducted to demonstrate that PA/US dual-modality imaging can effectively localize the MC.ResultsThe PA/US dual-modality imaging can identify and localize the MC. In clinical trials encompassing four patients and five MCs, the recognition rate was ∼80%. Three experiments to verify the accuracy of marker position recognition were successful.ConclusionsWe effectively localized the MC in real time using PA/US dual-modality imaging. Unlike other techniques, the new method enables surgeons to pinpoint nodules both preoperatively and intraoperatively. In addition, it boasts non-radioactivity and is comparatively cost-effective.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.