British Journal of Anaesthesia, Vol 84, Issue 1 38-42, Copyright © 2000 by Oxford University Press
AE Young, TJ Germon, NJ Barnett, AR Manara and RJ Nelson
To test theoretical assumptions supporting the use of near-infrared
spectroscopy (NIRS) in clinical practice, we examined the behaviour of NIR
light transmission and attenuation in the human head. Sterile probes for
emitting and detecting NIR light at a fixed separation of 40 mm were placed
in turn on intact skin, skull, dura and cerebral cortex of 10 patients
undergoing elective neurosurgery. In the first five patients, the detecting
probe was moved through successive extracerebral layers with the emitter on
the skin surface. In the second five patients, the process was reversed,
with the emitting probe moved and the detector in the same place on the
scalp. NIR intensity was measured at each tissue interface and compared
with the intensity measured at the skin surface with all layers intact.
Removal of bone and dura from the light path caused a significant reduction
in detected intensity. The largest mean reduction in light intensity was a
14-fold decrease with removal of bone (unadjusted P < 0.0001; paired t
test). The assumptions that extracerebral tissues contribute little to
attenuation of NIR light in the adult head and that most of this
attenuation occurs superficially in the scalp are drawn into question by
this study. We postulate that the skull and/or its interface with other
layers may act as an optical 'channel', distorting the behaviour of NIR
light in the human head.
ARTICLES
Behaviour of near-infrared light in the adult human head: implications for clinical near-infrared spectroscopy
Department of Anaesthesia, Frenchay Hospital, Bristol, UK.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  K. Yoshitani, M. Kawaguchi, T. Okuno, T. Kanoda, Y. Ohnishi, M. Kuro, and M. Nishizawa Measurements of Optical Pathlength Using Phase-Resolved Spectroscopy in Patients Undergoing Cardiopulmonary Bypass Anesth. Analg., February 1, 2007; 104(2): 341 - 346. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Steinbrink, T. Fischer, H. Kuppe, R. Hetzer, K. Uludag, H. Obrig, and W. M. Kuebler Relevance of depth resolution for cerebral blood flow monitoring by near-infrared spectroscopic bolus tracking during cardiopulmonary bypass. J. Thorac. Cardiovasc. Surg., November 1, 2006; 132(5): 1172 - 1178. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Olsson and S. Thelin Regional cerebral saturation monitoring with near-infrared spectroscopy during selective antegrade cerebral perfusion: Diagnostic performance and relationship to postoperative stroke J. Thorac. Cardiovasc. Surg., February 1, 2006; 131(2): 371 - 379. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. D. Stoneham and T. Martin Increased oxygen administration during awake carotid surgery can reverse neurological deficit following carotid cross-clamping Br. J. Anaesth., May 1, 2005; 94(5): 582 - 585. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. G. Al-Rawi, P. Smielewski, and P. J. Kirkpatrick Evaluation of a Near-Infrared Spectrometer (NIRO 300) for the Detection of Intracranial Oxygenation Changes in the Adult Head Stroke, November 1, 2001; 32(11): 2492 - 2500. [Abstract] [Full Text] [PDF]
|
|