TD-Master_DE

402 views
343 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
402
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
24
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

TD-Master_DE

  1. 1. Near infrared spectroscopy
  2. 2. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 3  First in vivo NIRS described by Frans Jöbsis 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
  3. 3. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 4 Therapeutic window  Minimal absorption in the „therapeutic window“ in the range 600- 1000nm -> maximal penetration depth  modified Beer-Lambert Law  Scattering )()( )()( 0          i iia aa x a c eII IdxdI a xs eII   0 c: concentration : molar absorption coefficient  cosg )1(' gss  reduced scattering coefficient scattering anisotropy factor
  4. 4. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 5 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
  5. 5. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 6 Different types of NIRS imaging Continuous wave Frequency domain Time of flight  This is a dummy text. Please ignore the content of this text. Exchange the dummy text with your own text.  It is really just a dummy text.  CW light source  record changes in transmission  used for pulse oxymetry measure relative oxygenation (SaO2)  relative inexpensive  This is a dummy text. Please ignore the content of this text. Exchange the dummy text with your own text.  It is really just a dummy text.  CW light source which is frequency modulated at high frequency (MHz)  Phase and amplitude is detected  can measure a and s ’  relative inexpensive  commercial versions  This is a dummy text. Please ignore the content of this text. Exchange the dummy text with your own text.  It is really just a dummy text.  pulsed laser source  measures mean time of flight (TOF) and intensity  depth selection is possible  can measure a and s ’  relative expensive  only at laboratory stage There are tree types of NIRS
  6. 6. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 7 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 a and s‘  )2/cos(exp 4 :Amplitude 0  A D S M   )2/cos()2/sin(:Phase  AA  )/(tan 1 ca  4/1 22 222         Dc c A a  Chance et al. 1998  ' 3 1 sa D   
  7. 7. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 8 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              Dct z cttzDctR a 4 expexp4),( 2 0 2 2/5 0 2/3   * 0 lz   ' 3 1 sa D    Patterson et al. 1989 
  8. 8. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 9 NIRS - Topography and Tomography  Optical topography: 2D determines 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
  9. 9. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 10 Applicatzion – Localization of brain regions  Topographic imaging for mapping of motor cortex  Activation of contralateral side  Also systemmic response LH finger tapping LH finger- tactile stimulation RH finger- tactile stimulation
  10. 10. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 12 Application - Functional studies in brain imaging  High density DOT system
  11. 11. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 13 Application - Functional studies in brain imaging
  12. 12. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 14 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
  13. 13. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 15 Literature  Diffuse optical imaging, Adam Gibson and Hamid Dehghani, 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 application M. Wolf, M. Ferrari, V. Quaresima, Journal of Biomedical Optics (2007) 12(6)  Time-Resolved Optical Tomography Instrumentation for Fast 3D Functional Imaging David K. Jennions, PhD Thesis, University of London 2008  Functional brain imaging by multi-wavelength time-resolved near infrared spectroscopy A. 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 tomography B. 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 Perspectives Y. 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
  14. 14. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 16 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 tissue B. 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
  15. 15. Markus Belau NIRS_20100615.ppt 15th of June 2010 Page 17 Any questions?

×