Structured light based hyperspectral time-resolved diffuse optical tomography system

Abstract

Time-resolved Diffuse Optical Tomography (DOT) has experienced rapid progress in recent years. It is a powerful functional imaging technique that allows acquiring abundant quantitative optical information from turbid media. However, the application of time domain DOT systems is hampered by the tradeoff between gathering dense data sets and practical acquisition times. Recently, wide-field structured illumination patterns have been applied in time-resolved DOT platforms to drastically accelerate the data acquisition process. In this work, we present a novel structured light based imaging strategy for DOT that can generate time domain datasets enriched by hyperspectral information with short data acquisition times. We employ two digital light processors to generate wide-field imaging pattern both in the illumination and detection channels to capture tomographic data sets over large areas. The hyperspectral data sets are acquired using a time-resolved spectrophotometer built around a multi-anode photomultiplier tube (PMT) that can detect photons in 16 wavelength channels simultaneously based on time-correlated single photon counting (TCSPC) technique. The characteristics of the system are tested in the spatial, temporal and spectral dimensions. The performance of the imaging system is validated through preliminary 3D reconstruction of absorption heterogeneity distribution within a murine model phantom. The application of digital light modulators in illumination and detection combined with timeresolved PMT spectrophotometer enables our system to acquire dense time domain data sets both in the spatial, temporal and spectral dimensions at an unprecedented speed. The phantom validation shows that proposed strategy is a promising technique for fast, high resolution, quantitative three dimensional volumetric imaging.