Measurement of blood flow in tissue provides vital information for the diagnosis and therapeutic monitoring of various vascular diseases. A noncontact, camera-based, near-infrared speckle contrast diffuse correlation tomography (scDCT) technique has been recently developed for 3D imaging of blood flow index (αDB) distributions in deep tissues up to a centimeter. A limitation with the continuous-wave scDCT measurement of blood flow is the assumption of constant and homogenous tissue absorption coefficient (µa). The present study took the advantage of rapid, high-density, noncontact scDCT measurements of both light intensities and diffuse speckle contrast at multiple source-detector distances and developed two-step fitting algorithms for extracting both µa and αDB. The new algorithms were tested in tissue-simulating phantoms with known optical properties and human forearms. Measurement results were compared against established near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS) techniques. The accuracies of our new fitting algorithms with scDCT measurements in phantoms (up to 16% errors) and forearms (up to 23% errors) are comparable to relevant study results (up to 25% errors). Knowledge of µa not only improved the accuracy in calculating αDB but also provided the potential for quantifying tissue blood oxygenation via spectral measurements. A multiple-wavelength scDCT system with new algorithms is currently developing to fit multi-wavelength and multi-distance data for 3D imaging of both blood flow and oxygenation distributions in deep tissues.
|Number of pages||15|
|Journal||Biomedical Optics Express|
|State||Published - Sep 1 2021|
Bibliographical noteFunding Information:
National Institutes of Health (R01-EB028792, R01-HD101508, R01-RF1AG062480, R21-AR062356, R21-HD091118, R21-NS114771, R56-NS117587); Plastic Surgery Foundation; National Science Foundation (EPSCoR #1539068).
© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics