Three-dimensional optical tomography of the premature infant brain.

For the first time, three-dimensional images of the newborn infant brain have been generated using measurements of transmitted light. A 32-channel time-resolved imaging system was employed, and data were acquired using custom-made helmets which couple source fibres and detector bundles to the infant head. Images have been reconstructed using measurements of mean flight time relative to those acquired on a homogeneous reference phantom, and using a head-shaped 3D finite-element-based forward model with an external boundary constrained to match the measured positions of the sources and detectors. Results are presented for a premature infant with a cerebral haemorrhage predominantly located within the left ventricle. Images representing the distribution of absorption at 780 nm and 815 nm reveal an asymmetry consistent with the haemorrhage, and corresponding maps of blood volume and fractional oxygen saturation are generally within expected physiological values.