Table 2.

Comparison of optical imaging to conventional functional imaging techniques

Techniques	Spatial resolution	Temporal resolution	Size/portability	Average cost (estimated per United States dollar)
fNIRS	Centimeter	Milliseconds	Small; portable	Thousands to tens of thousands
DOT	Millimeter	Milliseconds	Small; portable	Thousands to tens of thousands
fMRI	Millimeter	Seconds	Large; not portable	Millions
EEG	Centimeter	Milliseconds	Small; portable	Thousands to tens of thousands
MEG	Centimeter	Milliseconds	Large; not portable	Millions
PET	Millimeter	Minutes	Large; not portable	Millions
SPECT	Centimeter	Minutes	Large; not portable	Hundreds of thousands