Hyperspectral reflectance imaging (HRI) represents an emerging technology with a wide range of current and potential clinical applications including cancer detection and tissue oximetry. However, there is currently a lack of standardized methods to assure the quality and consistency of HRI imaging instruments. The lack of a standard battery of well-validated methods for objective, quantitative evaluation of HRI limits innovation in academia and industry and hampers the regulatory process by increasing the burden on manufacturers to develop preclinical test methods and perform clinical studies to demonstrate the effectiveness of new products. This proposed study will result in novel, validated image quality test methods and phantom fabrication techniques as well as improved understanding of spectral imaging systems such as those that have been submitted to FDA. Thus, this project will enhance FDA?s ability to rapidly evaluate innovative technologies based on HRI that have a strong potential to improve public health.
Background: Hyperspectral reflectance imaging (HRI) represents an emerging technology with a wide range of current and potential clinical applications including cancer detection and tissue oximetry. However, there is currently a lack of standardized methods to assure the quality and consistency of HRI imaging instruments. The lack of a standard battery of well-validated methods for objective, quantitative evaluation of HRI limits innovation in academia and industry and hampers the regulatory process by increasing the burden on manufacturers to develop preclinical test methods and perform clinical studies to demonstrate the effectiveness of new products. Results: This study developed innovative phantom-based test methods for quantitative and objective evaluation of HRI performance. New technologies such as 3D printing and silicone molding with photolithography were investigated and applied in phantom fabrication. The fabricated polymer phantoms are stable, long lasting, and well-controlled, and they contain subsurface channels that can be injected with HRI contrast agents such as hemoglobin and gold nanoparticles to mimic blood vessels or contrast agents targeting tumors. These phantoms form the basis of standardized tests. Algorithms for quantitatively analyzing the performance of the HRI were developed for the experimental data obtained with the polymer phantoms. The results of the project have been presented in 4 conferences, published in 1 academic journal and 2 conference proceedings, and 2 more academic journal publications are in preparation. Intellectual Merits: These novel, validated phantom fabrication techniques and image quality test methods as well as improved understanding of spectral imaging systems initiate the formation of standardized tests for HRI systems, which will enhance FDA’s ability to rapidly evaluate innovative technologies based on HRI. It will also provide standardized evaluation methods for manufacturers to improve and demonstrate their product quality. These tests also provide established techniques for rapid yet rigorous quality assurance testing for clinicians. This study also provides extensive insights into the factors influencing HRI imaging of both endogenous tissue structures and nanoparticle-labeled tumors. Insights gained regarding optimal methods for image quality assessment promise to advance nanotechnology-based cancer therapy/imaging as well as other HRI applications, such as vascular imaging and assessment of tissue oximetry. The project will contribute to healthcare through its development of well-validated test phantoms that can be used by academic and industrial researchers to hasten technological advancement and translation from laboratory to clinical implementation. Broader Impact: The project contributes to healthcare through its development of well-validated test phantoms that can be used by academic and industrial researchers to facilitate technological advancement and translation from laboratory to clinical implementation. This work leveraged the complementary expertise of two research groups at UMD and FDA to generate regulatory-relevant findings with high relevance to the biomedical engineering community. The PI organized a one-day workshop titled "International Workshop on Tissue Phantoms and Standardization in Biophotonics" at the University of Maryland Campus. 20 invited lectures were given by experts in the field of optical imaging and phantom development, from worldwide. 55 attendees from governmental institutions (52%), academia (42%) and industry (6%) attended the meeting and joined the discussion. The workshop marked the formation of a community of scientists and regulators in the field of regulatory science for biophotonics imaging. The discussion will continue, and more collaboration and rapid advance in the field are expected to happen along the way. This research work was also seamlessly integrated with educational, mentoring, and outreach activities to advance the cross-disciplinary program in the field of biophotonics and regulatory science. The research results have been integrated into the lectures focus on HRI and phantoms in undergraduate and graduate courses at the UMD, and an independent research course for a master student. 5 first-year graduate students participated in the research through 6-week rotation periods. Among them, 2 students joined the PI's lab for PhD thesis research. 2 undergraduate students participated the research work through summer internship. The PI collaborated with the Women in Engineering (WIE) at UMD to organized one Leadership, Enhancement, Application and Design (LEAD) Academy, which is a one day workshop with ~20 high school students, where the PI and lab members provided vivid illustrations and hands-on experience to enhance the women students’ understanding of biomedical optics. The PI also collaborated with Ms. Sarah Tanguy, the guest curator of the American Center for Physics (ACP) for organizing an art exhibition based on biomedical imaging including optical images to 1,500-2,000 attendees.
