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TD-Master_DE

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    TD-Master_DE TD-Master_DE Presentation Transcript

    • Near infrared spectroscopy
    • Motivation
      1
      Physical Principle and Set-up
      2
      New approaches
      3
      Applications
      4
      Literature
      5
      Agenda
    • First in vivo NIRS described by FransJöbsis 1977
      Revotionised anesthesia (Pulsoxymetry)
      Near infrared spectroscopy (NIRS) is currently mainly used to investigate cerebral oxygenation
      Mostly used in Neonatology (can be measured continuously). Babies don‘t have to be moved (as in MRI)
      Functional near infrared spectroscopy (fNIRS) – especially important for auditory studies (MRI is loud)
      can be used continuously
      low absorption (no heating), low energy (no ionization)
      relatively inexpensive
      Motivation
    • Therapeutic window
      Minimal absorption in the „therapeutic window“ in the range 600-1000nm -> maximal penetration depth
      modified Beer-Lambert Law
      Scattering
      c: concentration
      e: molar absorption coefficient
      reducedscatteringcoefficient
      scatteringanisotropyfactor
    • Physical Principle
      There are several physiologically interesting molecules with characteristic absorption spectra in the NIR region
      Especially: oxy-haemaglobin (HbO) and deoxy-haemoglobin (HHb)
      Other chromophores: water, lipids, melanin, cytochrome c oxidase
      isosbestic
      point
    • Different types of NIRS imaging
      There are tree types of NIRS
      Continuous wave
      Frequency domain
      Time of flight
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      • CW light source
      • record changes in transmission
      • used for pulse oxymetrymeasure relative oxygenation (SaO2)
      • relative inexpensive
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      • CW light source which is frequency modulated at high frequency (MHz)
      • Phase and amplitude is detected
      • can measure ma and ms’
      • relative inexpensive
      • commercial versions
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      • pulsed laser source
      • measures mean time of flight (TOF) and intensity
      • depth selection is possible
      • can measure ma and ms’
      • relative expensive
      • only at laboratory stage
    • Frequency Domain NIRS
      Continuous wave light sources modulated by a radio-frequency signal (typically 50-500MHz)
      Amplitude and phase are usually measured
      Can separate between ma and ms‘
      Chance et al. 1998
    • Time Domain NIRS
      Temporal distribution of photons is measured, which is produced when a short duration pulse of light is transmitted through medium
      Different parts of the temporal point spread function (TPSF) give information about different depths inside the tissue
      zero distance measurements are possible
      Patterson et al. 1989
      r
    • NIRS - Topography and Tomography
      Optical topography: 2Ddetermines concentration of HHb and HbO2 at a given depth
      Multiple measurements of diffuse reflectance are acquired at small source-detector separation over large tissue areas
      Study haemodynamics changes e.g. changes in cortex, currently most common CW application
      Used for localization of specific cortical regions e.g. motor cortex
      Optical tomography: 3D
      Different depths are probed
      Higher lateral resolution and better localization
    • Applicatzion – Localizationofbrainregions
      Topographicimagingformappingofmotorcortex
      Activationofcontralateralside
      Also systemmicresponse
      LH fingertapping
      LH finger-tactilestimulation
      RH finger-tactilestimulation
    • Applications
      Main Application of NIRS are
      Brain imaging
      Breast cancer screening
      Mammography has radiation exposure and a high number of false positives
      NIRS has
      Muscle oxygenation
    • Application - Functional studies in brain imaging
      High density DOT system
    • Application - Functional studies in brain imaging
    • Application - Breast imaging
      One of the main tumors in females
      Breast cancer imaging is usually performed with
      Mammography: many false positives, x-rays (radiation damage)
      ultrasound:
      biopsy: invasive; only for suspicious areas
      NIRS is non-invasive and has no ionizing radiation
    • Literature
      Diffuse optical imaging,Adam Gibson and HamidDehghani, Phil. Trans. R. Soc. A (2009) 367 3055-3072
      Recent advances in diffuse optical imaging, A. P. Gibson, J. C. Hebden, and S. R. Arridge, Phys. Med. Biol. (2005) 50 R1-R43
      Progress of near-infrared spectroscopy and tomography for brain and muscle clinical applicationM. Wolf, M. Ferrari, V. Quaresima, Journal of Biomedical Optics (2007) 12(6)
      Time-Resolved Optical Tomography Instrumentation for Fast 3D Functional ImagingDavid K. Jennions, PhD Thesis, University of London 2008
      Functional brain imaging by multi-wavelength time-resolved near infrared spectroscopyA. Torricelli, D. Contini, A. Pifferi, L. Spinelli and R. Cubeddu, Opto-Electronics review (2008) 16(2) 131-135
      Retinotopic mapping of adult human visual cortex with high-density diffuse optical tomographyB. W. Zeff, B. R. White, H. Dehghani, B. L. Schlaggar, and J. P. Culver, PNAS (2007) 104(29) 12169-12174
      Optical Imaging of Infants’ Neurocognitive Development: Recent Advances and PerspectivesY. Minagawa-Kawai, K. Mori, J. C. Hebden, E. Dupoux, Developmental Neurobiology (2008) 68 712-728
      Methodology development for three-dimensional MR-guided near infrared spectroscopy of breast tumors C. M. Carpenter, S. Srinivasan, B. W. Pogue, K. D. Paulsen, OPTICS EXPRESS (2008) 16(22) 17903
    • Literature
      Recent applications of near-infrared spectroscopy in cancer diagnosis and therapy V. R. Kondepati, H. M. Heise, J. Backhaus, Anal. Bioanal. Chem. (2008) 390:125–139
      Time-domain optical mammography: initial clinical results on detection and characterization of breast tumors D. Grosenick, K. T. Moesta, H. Wabnitz, J. Mucke, C. Stroszczynski, R. Macdonald, P. M. Schlag, H. Rinneberg, Appl. Opt. (2003) 42(16) 3170-3196
      Concentration and oxygen saturation of haemoglobin of 50 breast tumours determined by time-domain optical mammography D. Grosenick, H. Wabnitz, K. T. Moesta, J. Mucke, M. Möller, C. Stroszczynski, J. Stößel, B. Wassermann, P. M. Schlag and H. Rinneberg, Phys. Med. Biol. (2004) 49 1165–1181
      Time-domain scanning optical mammography: I. Recording and assessment of mammograms of 154 patients D. Grosenick, K. T. Moesta, M. Möller, J. Mucke, H. Wabnitz, B. Gebauer, C. Stroszczynski,B. Wassermann, P. M Schlag and H. Rinneberg, Phys. Med. Biol. (2005) 50 2429–2449
      Phase measurement of light absorption and scatter in human tissueB. Chance, M. Cope, E. Gratton, N. Ramanujam, B. Tomberg, Rev. Sci. Instrum. (1998) 69(10) 3457-3481
      Time resolved reflectance and transmittance for the noninvasive measurement of tissue optical properties M. S. Patterson , B. Chance, can B. C. Wilson, Appl. Opt. (1989) 28(12) 2331-2336
    • Any questions?
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      Time-domain fNIRS (TD-fNIRS)
    • Neuroscience: Human Motor Area
      PROTOCOL:
      • 20s BASELINE
      • 20s TASK: Finger Tapping (right hand)
      • 40s RECOVERY
      DATA ACQUISITION:
      • Acq. Time: 1 s/channel
      2 cm
      D1
      S1
      Measurements performed in collaboration with:
      L. Fadiga and L. Craighero, University of Ferrara (Ferrara, ITALY).
    • Neuroscience: Human Motor Area
      (Sensitivity)
      Baseline
      Task
      Recovery
      Single Trials
      Averaged on 9 trials
    • Neuroscience: Human Motor Area
      (Localization)
      DO2HB & DHHB
      0
      20
      40
      80
      Time (s)
      POSITIONS OF SOURCES AND DETECTORS
      PROTOCOL:
      • 20s BASELINE
      • 20s TASK: Finger Tapping (right hand)
      • 40s RECOVERY
      DATA ACQUISITION:
      • Acq. Time: 1 s/channel
    • Neuroscience: Human Motor Area
      (Discrimination)
      PROTOCOL:
      • 15s BASELINE
      • 15s TASK: Finger Tapping (right hand)
      Shoulder Rotation (right shoulder)
      • 30s RECOVERY