Jeremy C. Hebden

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We review the current state-of-the-art of diffuse optical imaging, which is an emerging technique for functional imaging of biological tissue. It involves generating images using measurements of visible or near-infrared light scattered across large (greater than several centimetres) thicknesses of tissue. We discuss recent advances in experimental methods(More)
The desire for a diagnostic optical imaging modality has motivated the development of image reconstruction procedures involving solution of the inverse problem. This approach is based on the assumption that, given a set of measurements of transmitted light between pairs of points on the surface of an object, there exists a unique three-dimensional(More)
Optical tomography has been used to reconstruct three-dimensional images of the entire neonatal head during motor evoked responses. Data were successfully acquired during passive movement of each arm on four out of six infants examined, from which eight sets of bilateral images of hemodynamic parameters were reconstructed. Six out of the eight images showed(More)
Near-infrared spectroscopy (NIRS) provides a unique method of monitoring infant brain function by measuring the changes in the concentrations of oxygenated and deoxygenated hemoglobin. During the past 10 years, NIRS measurement of the developing brain has rapidly expanded. In this article, a brief discussion of the general principles of NIRS, including its(More)
Near-infrared spectroscopy has been used to record oxygenation changes in the visual cortex of 4 month old infants. Our in-house topography system, with 30 channels and 3 different source-detector separations, recorded changes in the concentration of oxy-, deoxy- and total haemoglobin (HbO2, HHb and HbT) in response to visual stimuli (face, scrambled visual(More)
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(More)
A time-resolved optical tomography system has been used to generate cross-sectional images of the human breast. Images are reconstructed using an iterative, nonlinear algorithm and measurements of mean photon flight time relative to those acquired on a homogeneous reference phantom. Thirty-eight studies have been performed on three healthy volunteers and 21(More)
The overwhelming scatter which occurs when optical radiation propagates through tissue severely limits the ability to image internal structure using measurements of transmitted intensity. A broad range of methods has been proposed during the past decade or so in order to improve imaging performance. Direct methods involve isolating an unscattered or(More)
We demonstrate experimentally the possibility of reproducing the phase function, absorption, and scattering coefficients of a real biological tissue (adult brain white matter and liver) using a suspension of polystyrene microspheres with a fractal size distribution. The design of a light scattering goniometer with a cylindrical cell in air is discussed, and(More)
There are no reliable values for the transport scattering coe cient ( 0 s ) of whole blood, particularly at the high hematocrits found in-vivo. Existing values are largely based on single scattering measurements of scattering crosssection and angular scattering. The accuracy of the single scattering method is limited by the accuracy with which the g-value(More)