COMPARING FNIRS HEMODYNAMICS TO FMRI HEMODYNAMICS

Compared to fMRI, fNIRS has different advantages and disadvantages. While fMRI has become the gold standard for in vivo imaging of the human brain, fNIRS stands out for its portability and robustness to noise, bringing functional imaging into realistic environments. While limited by its inferior spatial resolution and penetration depth, fNIRS has a much higher temporal resolution than fMRI, allowing measurements of concentration changes in both oxygenated and deoxygenated hemoglobin.

It is therefore of interest to many researchers how NIRS compares to fMRI in studies of brain function. While concurrent fMRI and fNIRS measurements have been mostly aiming at validating fNIRS as newer technology and studying the spatial and temporal correlations between the fMRI BOLD signal and the concentration changes in oxygenated and deoxygenated hemoglobin, it is evident that combined fNRIS and fMRI can give new insights into brain function by overcoming some of their intrinsic limitations.

The optical nature of the NIRS signal and its robustness to motion, as well as the size and portability of fNIRS devices, makes fNIRS an ideal candidate for multimodality studies. fNIRS can efortlessly be combined with fMRI, EEG, TMS, tDSC and many other brain imaging modalities, without causing any measurement interferences.