title: Reduced-order modeling of light transport in tissue for real-time monitoring of brain hemodynamics using diffuse optical tomography.
abstract: This paper proposes a new reconstruction method for diffuse optical tomography using reduced-order models of light transport in tissue. The models, which directly map optical tissue parameters to optical flux measurements at the detector locations, are derived based on data generated by numerical simulation of a reference model. The reconstruction algorithm based on the reduced-order models is a few orders of magnitude faster than the one based on a finite element approximation on a fine mesh incorporating a priori anatomical information acquired by magnetic resonance imaging. We demonstrate the accuracy and speed of the approach using a phantom experiment and through numerical simulation of brain activation in a rat's head. The applicability of the approach for real-time monitoring of brain hemodynamics is demonstrated through a hypercapnic experiment. We show that our results agree with the expected physiological changes and with results of a similar experimental study. However, by using our approach, a three-dimensional tomographic reconstruction can be performed in ∼3  s per time point instead of the 1 to 2 h it takes when using the conventional finite element modeling approach.
authors: University of Sheffield, Department of Automatic Control and Systems Engineering, Mappin Street, Sheffield, S1 3JD, United Kingdom.
authors: Ernesto E
authors: EE
authors: Vidal-Rosas
authors: University of Sheffield, Department of Automatic Control and Systems Engineering, Mappin Street, Sheffield, S1 3JD, United Kingdom.
authors: Stephen A
authors: SA
authors: Billings
authors: University of Sheffield, Centre for Signal Processing in Neuroimaging and Systems Neuroscience, Department of Psychology, Western Bank, Sheffield, S10 2TN, United Kingdom.
authors: Ying
authors: Y
authors: Zheng
authors: University of Sheffield, Centre for Signal Processing in Neuroimaging and Systems Neuroscience, Department of Psychology, Western Bank, Sheffield, S10 2TN, United Kingdom.
authors: John E
authors: JE
authors: Mayhew
authors: University of Sheffield, Centre for Signal Processing in Neuroimaging and Systems Neuroscience, Department of Psychology, Western Bank, Sheffield, S10 2TN, United Kingdom.
authors: David
authors: D
authors: Johnston
authors: University of Sheffield, Centre for Signal Processing in Neuroimaging and Systems Neuroscience, Department of Psychology, Western Bank, Sheffield, S10 2TN, United Kingdom.
authors: Aneurin J
authors: AJ
authors: Kennerley
authors: University of Sheffield, Department of Automatic Control and Systems Engineering, Mappin Street, Sheffield, S1 3JD, United Kingdom.
authors: Daniel
authors: D
authors: Coca
mesh_terms: D000465:Algorithms; D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000098:blood supply*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003198:Computer Simulation; D005260:Female; D006257:Head / Q000033:anatomy & histology; D006439:Hemodynamics / Q000502:physiology*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D019047:Phantoms, Imaging; D051381:Rats; D019265:Spectroscopy, Near-Infrared; D041622:Tomography, Optical / Q000295:instrumentation / Q000379:methods*