Optimizing subtraction-based approaches in time-domain diffuse optics by a time-window analysis

Diffuse optics measurements performed in the time domain provide the highest information level, but are plagued by a low spatial resolution and significant sensitivity to superficial regions (e.g., extracerebral changes). Here we compare the two main analysis methods (namely, statistical moments and time-windowing of the photon time-of-flight distribution) with the recently introduced dual-slope method. Both in-silico and phantom studies are performed. Our results show that time-windowing, although not previously applied in this context, maximizes the advantages of a dual-slope approach while also maximizing the depth selectivity. Furthermore, for time-windowing, a triple-slope approach is proposed, demonstrating superior rejection of superficial changes.