Abstract
Significance: The sensitivity to extracerebral tissues is a well-known confounder of diffuse optics. Two-layer (2L) head models can separate cerebral signals from extracerebral artifacts, but they also carry the risk of crosstalk between fitting parameters.
Aim: We aim to implement a constrained 2L head model for hybrid diffuse correlation spectroscopy (DCS) and frequency-domain diffuse optical spectroscopy (FD-DOS) data and to characterize errors in cerebral blood flow and tissue absorption with the proposed model.
Approach: The algorithm uses the analytical solution of a 2L cylinder and an a priori extracerebral layer thickness to fit multidistance FD-DOS (0.8 to 4 cm) and DCS (0.8 and 2.5 cm) data, assuming homogeneous tissue reduced scattering. We characterized the algorithm's accuracy for simulated data with noise generated using a 2L slab and realistic adult head geometries and for in vitro phantom data.
Results: Our algorithm recovered the cerebral flow index with 6.3 [2.8, 13.2]% and 34 [30, 42]% (median absolute percent error [interquartile range]) for slab and head geometries, respectively. Corresponding errors in the cerebral absorption coefficient were 5.0 [3.0, 7.9]% and 4.6 [2.4, 7.2]% for the slab and head geometries and 8 [5, 12]% for our phantom experiment. Our results were minimally sensitive to second-layer scattering changes and were robust to cross-talk between fitting parameters.
Conclusions: In adults, the constrained 2L algorithm promises to improve FD-DOS/DCS accuracy compared with the conventional semi-infinite approach.
Original language | English |
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Article number | 025008 |
Number of pages | 26 |
Journal | Neurophotonics |
Volume | 10 |
Issue number | 2 |
DOIs | |
Publication status | Published - 23 May 2023 |
Bibliographical note
Funding Information:This work was funded by the São Paulo Research Foundation [Grant Nos. 2014/25468-6 (R.M.F), 2013/07559-3 (R.C.M), and 2019/25281-9 (G.G.M.)], the National Institutes of Health [Grant No. R01NS113945 (W.B.B.)], and the Children’s Hospital of Philadelphia Frontier Program (W.B.B.).
Publisher Copyright:
© 2023 The Authors. Published by SPIE.
Keywords
- diffuse correlation spectroscopy
- diffuse optical spectroscopy
- hybrid diffuse optics
- multidistance
- multilayer model
ASJC Scopus subject areas
- Neuroscience (miscellaneous)
- Radiological and Ultrasound Technology
- Radiology Nuclear Medicine and imaging