Abstract

The concentration changes in oxygenated and deoxygenated haemoglobin in the exposed cortex of guinea pigs evoked by the auditory stimulation are measured by the multi-spectral imaging to investigate the relationship between spatial extent of the brain activation determined by the statistical analysis and the SNR of the concentration changes in oxygenated and deoxygenated haemoglobin. The SNR of the concentration change in oxygenated haemoglobin measured by the multi-spectral imaging is generally greater than that of deoxygenated haemoglobin. The difference in SNR tends to affect the result of the spatial extent of brain activation estimated from the changes in oxygenated and deoxygenated haemoglobin. The influence of the SNR on the spatial extent is evaluated by a numerical experiment. The results of the numerical experiment are compared with the spatial extent of the brain activation estimated from the changes in oxygenated and deoxygenated haemoglobin in the exposed cortex of guinea pigs evoked by the auditory stimulation. It is found that the spatial extent of the brain activation decreases with a decrease in SNR of the concentration change. The difference in spatial extent of the brain activation estimated from the concentration changes in oxygenated and deoxygenated haemoglobin is affected by the SNR of signal.

© 2009 OSA/SPIE