Towards next-generation time-domain diffuse optics for extreme depth penetration and sensitivity

Abstract

Light is a powerful tool to non-invasively probe highly scattering media for clinical applications ranging from oncology to neurology, but also for molecular imaging, and quality assessment of food, wood and pharmaceuticals. Here we show that, for a paradigmatic case of diffuse optical imaging, ideal yet realistic time-domain systems yield more than 2-fold higher depth penetration and many decades higher contrast as compared to ideal continuous-wave systems, by adopting a dense source-detector distribution with picosecond time-gating. Towards this aim, we demonstrate the first building block made of a source-detector pair directly embedded into the probe based on a pulsed Vertical-Cavity Surface-Emitting Laser (VCSEL) to allow parallelization for dense coverage, a Silicon Photomultiplier (SiPM) to maximize light harvesting, and a Single-Photon Avalanche Diode (SPAD) to demonstrate the time-gating capability on the basic SiPM element. This paves the way to a dramatic advancement in terms of increased performances, new high impact applications, and availability of devices with orders of magnitude reduction in size and cost for widespread use, including quantitative wearable imaging. Opt. 19, 086012 (2014). 26. S. Carraresi, T. S. Shatir, F. Martelli, and G. Zaccanti, "Accuracy of a perturbation model to predict the effect of scattering and absorbing inhomogeneities on photon migration," Appl. Opt. 40, 4622-4632 (2001). 27. D. Contini, F. Martelli, and G. Zaccanti, "Photon migration through a turbid slab described by a model based on diffusion approximation. I. Theory," Appl. Opt. 36, 4587-4599 (1997). #230929Received 23

Collagen content as a risk factor in breast cancer? A pilot clinical study.

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Chromophore decomposition in multispectral time-resolved diffuse optical tomography

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“…In particular, demonstrations of Silicon PhotoMultiplier (SiPM) in diffuse optics and TR DOT were presented in previous papers [13,14]. These and other cost-effective solutions (e.g.…”

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