We investigate the optical properties of the brain in 23 neonates in vivo using a frequency domain near-infrared spectroscopy (NIRS). In this study, a calibration procedure is employed to determine the absorption and reduced scattering coefficients with single source-detector separation. The absorption coefficients of the infant foreheads are lower than the values reported in adults. A large intersubject variation in the reduced scattering coefficients is also demonstrated. Furthermore, physiological parameters are derived from the absorption coefficients at two wavelengths (788 and 832 nm). The mean total hemoglobin concentration (THC) is 39.7+/-9.8 microM and the mean cerebral blood oxygen saturation (StO2) is 58.7+/-11.2%. Our preliminary results show that this bedside frequent domain NIRS could provide quantitative optical measurement of the infant brain.

Background Assessments of cortical development and identifying factors that may result in a poor prognosis for fetuses with isolated mild ventriculomegaly (IMVM) is a hot research topic. We aimed to perform a constant, detailed assessment of cortical development in IMVM fetuses using ultrasound and determine whether asymmetric cortical development occurred. Moreover, we aimed to estimate the prognosis of IMVM fetuses and compare the difference in the prognosis of IMVM fetuses presenting symmetric and asymmetric cortical maturation. Methods IMVM was diagnosed by regular ultrasound, neurosonography and fetal MRI. Genetic and TORCH examinations were conducted to exclude common genetic abnormalities and TORCH infection of fetuses. Ultrasound examinations were conducted at an interval of 2–3 weeks to record sulcus development in IMVM fetuses using a scoring system. The neonatal behavioral neurological assessment (NBNA), the Ages and Stages Questionnaire, Third Edition (ASQ-3) and the Bayley Scales of Infant Development, First Edition (BSID-I) were performed after birth. Results Forty fetuses with IMVM were included: twenty showed asymmetric cortical maturation and twenty showed symmetric cortical maturation. For IMVM fetuses presenting asymmetric cortical maturation, the mean gestational age (GA) at the first diagnosis of relatively delayed development was 24.23 weeks for the parieto-occipital sulcus, 24.71 weeks for the calcarine sulcus, and 26.43 weeks for the cingulate sulcus. All the sulci with delayed development underwent ‘catch-up growth’ and developed to the same grade as the sulci of the other hemisphere. The mean GA at which the two sides developed to the same grade was 29.40 weeks for the parieto-occipital sulcus, 29.30 weeks for the calcarine sulcus and 31.27 weeks for the cingulate sulcus. The NBNA, ASQ-3 and BSID-I scores of all patients were in the normal range. Conclusions IMVM fetuses may show mild asymmetric cortical maturation in the second trimester, but the relatively delayed sulci undergo ‘catch-up growth’. The neurodevelopment of IMVM fetuses presenting asymmetric cortical maturation and ‘catch-up growth’ is not statistically significantly different from IMVM fetuses presenting symmetric cortical maturation.