title: High-speed multi-exposure laser speckle contrast imaging with a single-photon counting camera.
abstract: Laser speckle contrast imaging (LSCI) has emerged as a valuable tool for cerebral blood flow (CBF) imaging. We present a multi-exposure laser speckle imaging (MESI) method which uses a high-frame rate acquisition with a negligible inter-frame dead time to mimic multiple exposures in a single-shot acquisition series. Our approach takes advantage of the noise-free readout and high-sensitivity of a complementary metal-oxide-semiconductor (CMOS) single-photon avalanche diode (SPAD) array to provide real-time speckle contrast measurement with high temporal resolution and accuracy. To demonstrate its feasibility, we provide comparisons between in vivo measurements with both the standard and the new approach performed on a mouse brain, in identical conditions.
authors: ICFO-Institut de Ciències Fotòniques, Av. Carl Friedrich Gauss, 3, Castelldefels (Barcelona), 08860, Spain.
authors: Tanja
authors: T
authors: Dragojević
authors: Politecnico di Milano, Dipartimento di Elettronica, Informatione e Bioingegneria, Piazza Leonardo Da Vinci, 25, Milan, 20133, Italy.
authors: Danilo
authors: D
authors: Bronzi
authors: ICFO-Institut de Ciències Fotòniques, Av. Carl Friedrich Gauss, 3, Castelldefels (Barcelona), 08860, Spain.
authors: Hari M
authors: HM
authors: Varma
authors: ICFO-Institut de Ciències Fotòniques, Av. Carl Friedrich Gauss, 3, Castelldefels (Barcelona), 08860, Spain.
authors: Claudia P
authors: CP
authors: Valdes
authors: Department of Brain Ischemia and Neurodegeneration, Insitute for Biomedical Reseach (IIBB), Spanish Research Council (CSIC), Insitut d'Investigacions Biomédical Research August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
authors: Clara
authors: C
authors: Castellvi
authors: Politecnico di Milano, Dipartimento di Elettronica, Informatione e Bioingegneria, Piazza Leonardo Da Vinci, 25, Milan, 20133, Italy.
authors: Federica
authors: F
authors: Villa
authors: Politecnico di Milano, Dipartimento di Elettronica, Informatione e Bioingegneria, Piazza Leonardo Da Vinci, 25, Milan, 20133, Italy.
authors: Alberto
authors: A
authors: Tosi
authors: Department of Brain Ischemia and Neurodegeneration, Insitute for Biomedical Reseach (IIBB), Spanish Research Council (CSIC), Insitut d'Investigacions Biomédical Research August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
authors: Carles
authors: C
authors: Justicia
authors: Politecnico di Milano, Dipartimento di Elettronica, Informatione e Bioingegneria, Piazza Leonardo Da Vinci, 25, Milan, 20133, Italy.
authors: Franco
authors: F
authors: Zappa
authors: ICFO-Institut de Ciències Fotòniques, Av. Carl Friedrich Gauss, 3, Castelldefels (Barcelona), 08860, Spain.
authors: Turgut
authors: T
authors: Durduran
keywords: (030.5260) Photon counting; (040.1345) Avalanche photodiodes (APDs); (110.6150) Speckle imaging; (300.6480) Spectroscopy, speckle