Recent advances in high speed diffuse optical imaging in biomedicine

Diffuse optical imaging (DOI) is a label-free, safe, inexpensive, and quantitative imaging modality that provides metabolic and molecular contrast in tissue using visible or near-infrared light. DOI modalities can image up to several centimeters deep in tissue, providing access to a wide range of human tissues and organ sites. DOI technologies have benefitted from several decades of academic research, which has provided a variety of platforms that prioritize imaging depth, resolution, field-of-view, spectral content, and other application-specific criteria. Until recently, however, acquisition and processing speeds have represented a stubborn barrier to further clinical exploration and implementation. Over the last several years, advances in high-speed data acquisition enabled by high-speed digital electronics, newly available sources and detectors, and innovative new scanning methods have led to major improvements in DOI rates. These advances are now being coupled with new data processing algorithms that utilize deep learning and other computationally efficient methods to provide rapid or real-time feedback in the clinic. Together, these improvements have the potential to help advance DOI technologies to the point where major impacts can be made in clinical care. Here, we review recent advances in acquisition and processing speed for several important DOI modalities.