The subject of superficial contamination and signal origins remains a widely debated topic in the field of
Near Infrared Spectroscopy (NIRS), yet the concept of using the technology to monitor an injured brain,
in a clinical setting, poses additional challenges concerning the quantitative accuracy of recovered
parameters.
Using high density diffuse optical tomography probes, quantitatively accurate parameters from
different layers (skin, bone and brain) can be recovered from subject specific reconstruction models. This
study assesses the use of registered atlas models for situations where subject specific models are not
available. Data simulated from subject specific models were reconstructed using the 8 registered atlas
models implementing a regional (layered) parameter recovery in NIRFAST. A 3-region recovery based
on the atlas model yielded recovered brain saturation values which were accurate to within 4.6%
(percentage error) of the simulated values, validating the technique. The recovered saturations in the
superficial regions were not quantitatively accurate. These findings highlight differences in superficial
(skin and bone) layer thickness between the subject and atlas models. This layer thickness mismatch was
propagated through the reconstruction process decreasing the parameter accuracy.