Imaging changes in blood volume and oxygenation in the newborn infant brain using three-dimensional optical tomography

Abstract

Induced haemodynamic and blood oxygenation changes occurring within the brain of a ventilated newborn infant have been imaged in three dimensions using optical tomography. Noninvasive measurements of the flight times of transmitted light were acquired during illumination of the brain by laser pulses at wavelengths of 780 nm and 815 nm. The oxygen and carbon dioxide partial pressures were adjusted through alterations to the ventilator settings, resulting in changes to the cerebral blood volume and oxygenation. Three-dimensional images were generated using the physiologically associated differences in the measured data, obviating the need for data calibration using a separate reference measurement. The results exhibit large changes in absorption coefficient at both wavelengths. Images corresponding to differences in concentrations of oxy- and deoxyhaemoglobin are in qualitative agreement with known physiological data.

Multi-channel medical device for time domain functional near infrared spectroscopy based on wavelength space multiplexing

“…It is worth mentioning that European research groups located in academic or public research centers have designed and built most of the existing TD fNIRS systems effectively employed in the clinics. In particular the most active in the field are the research groups at Physikalisch-Technische Bundesanstalt, Berlin, Germany [9][10][11][12][13][14][15], at the Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland [16][17][18], and at the the Department of Medical Physics and Bioengineering, University College London [19][20][21][22][23]. In the US we can mention the group at the Massachusetts General Hospital, Athinoula A. Martinos Center, Charlestown, Massachusetts [6,[24][25][26].…”

Early photon tomography allows fluorescence detection of lung carcinomas and disease progression in mice in vivo

“…Photographic and planar-fluorescence-imaging implementations of this approach offer only 2-dimensional views and largely qualitative data, because they do not consider the nonlinear relation of photon strength to lesion depth and tissue optical properties. In response, tomographic approaches have been developed to overcome the limitations of these methods (6)(7)(8). Optical tomography utilizes multiprojection measurements and physical models of photon propagation to quantitatively retrieve fluorochrome biodistribution in tissues.…”

Near-Infrared Spectroscopy

“…However, frequency domain systems are unable to identify unwanted light that is temporally correlated with the measurement, such as light that has leaked around the object being imaged. In the time domain inspection of the TPSF can enable these contaminated measurements to be rejected (Hebden et al, 2004).…”