In vivo measure of neonate brain optical properties and hemodynamic parameters by time-domain near-infrared spectroscopy

By exploiting a multichannel portable instrument for time-domain near-infrared spectroscopy (TD-NIRS), we characterized healthy neonates' brains in term of optical properties and hemodynamic parameters. In particular, we assessed the absolute values of the absorption and reduced scattering coefficients at two wavelengths, together with oxy-, deoxy- and total hemoglobin concentrations, and the blood oxygen saturation of the neonates' brains. In this study, 33 healthy full-term neonates were tested, obtaining the following median values: 0.28 and 0.31cm-1 for μa at 690 and 820 nm, respectively; 5.8 and 5.3cm-1 for μs′ at 690 and 820 nm, respectively; 103μM for cO2Hb; 42.6μM for cHHb; 146μM for ctHb; 72% for sO2. In general, the agreement of these values with the sparse existing literature appears not always consistent. These findings demonstrate the first measurements of optical properties of the healthy neonate brain using TD-NIRS and show the need for clarification of optical properties across methods and populations.