title: Localized near-infrared spectroscopy and functional optical imaging of brain activity.
abstract: Changes in cerebral blood flow (CBF) and cerebral metabolic rates (CMRO2) have been used as indices for changes in neuronal activity. Near-infrared spectroscopy (NIRS) can also measure cerebral haemodynamics and metabolic changes, enabling the possible use of multichannel recording of NIRS for functional optical imaging of human brain activity. Spatio-temporal variations of brain regions were demonstrated during various mental tasks. Non-synchronous behaviour of cerebral haemodynamics during the neuronal activation was observed. Gender- and handedness-dependent lateralization of the function between right and left hemispheres was demonstrated by simultaneous measurement using two NIR instruments during the mirror-drawing task. A lack of interhemispheric integration was observed with schizophrenic patients. These observations suggest an application for NIRS in psychiatric disease management, as an addition to clinical monitoring at the bedside. A time resolved 64-channel optical imaging system was constructed. This consisted of three picosecond laser diodes and 64 channels of TAC and CFD systems. Image reconstruction for phantom model systems was performed. Time-resolved quantitative optical imaging will become real in the very near future.
authors.affiliation: Biophysics Division, Hokkaido University, Sapporo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tamura
authors.forename: Y
authors.initials: Y
authors.lastname: Hoshi
authors.forename: F
authors.initials: F
authors.lastname: Okada
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D004569:Electroencephalography; D006439:Hemodynamics; D006454:Hemoglobins / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010108:Oxyhemoglobins / Q000032:analysis / Q000378:metabolism*; D012039:Regional Blood Flow; D012146:Rest; D012559:Schizophrenia / Q000378:metabolism / Q000503:physiopathology; D012890:Sleep / Q000502:physiology; D013055:Spectrophotometry, Infrared / Q000295:instrumentation / Q000379:methods*
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins