scholarly journals Non-Invasive Measurement Of Tissue Chromophore Concentrations And Cerebral Blood Flow Using Broad-Band Continuous Wave Near Infrared Spectroscopy

2021 ◽  
Author(s):  
Hadi Zabihi-Yeganeh
Keyword(s):  
Blood Flow ◽  
Optical Properties ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Indocyanine Green ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Continuous Wave ◽  
Broad Band ◽  
Optical Properties Of Tissue

We present a broad-band, continuous wave spectral approach to quantify the baseline optical properties of tissue, in particular the absolute absorption and scattering properties and changes in the concentrations of chromophores, which can assist to quantify the regional blood flow from dynamic contrast-enhanced near-infrared spectroscopy data. Experiments were conducted on phantoms and piglets. The baseline optical properties of tissue were determined by performing a multi-parameter wavelength-dependent differential data fit of the near infrared reflectance spectrum between 680 nm and 970 nm of a photon diffusion equation solution for a semi-infinite homogeneous medium. These baseline optical properties of the piglet head tissue were used to quantify the temporal dynamics of the concentration of the intravenously administered contrast agent Indocyanine Green in the piglet brain. The temporal traces of the Indocyanine Green concentration measured by our method were used to estimate the cerebral blood flow using a bolus tracking technique.

scholarly journals Non-Invasive Measurement Of Tissue Chromophore Concentrations And Cerebral Blood Flow Using Broad-Band Continuous Wave Near Infrared Spectroscopy

2021 ◽  
Author(s):  
Hadi Zabihi-Yeganeh
Keyword(s):  
Blood Flow ◽  
Optical Properties ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Indocyanine Green ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Continuous Wave ◽  
Broad Band ◽  
Optical Properties Of Tissue

We present a broad-band, continuous wave spectral approach to quantify the baseline optical properties of tissue, in particular the absolute absorption and scattering properties and changes in the concentrations of chromophores, which can assist to quantify the regional blood flow from dynamic contrast-enhanced near-infrared spectroscopy data. Experiments were conducted on phantoms and piglets. The baseline optical properties of tissue were determined by performing a multi-parameter wavelength-dependent differential data fit of the near infrared reflectance spectrum between 680 nm and 970 nm of a photon diffusion equation solution for a semi-infinite homogeneous medium. These baseline optical properties of the piglet head tissue were used to quantify the temporal dynamics of the concentration of the intravenously administered contrast agent Indocyanine Green in the piglet brain. The temporal traces of the Indocyanine Green concentration measured by our method were used to estimate the cerebral blood flow using a bolus tracking technique.

Near-infrared spectroscopy extended with indocyanine green dye dilution for cerebral blood flow measurement: Median values in healthy volunteers

2008 ◽  
Vol 16 (3) ◽  
Author(s):  
R. Mudra ◽  
C. Muroi ◽  
P. Niederer ◽  
E. Keller
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Indocyanine Green ◽  
Healthy Volunteers ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Flow Index ◽  
Vascular Perfusion ◽  
Dye Dilution

AbstractThe cerebral blood flow (CBF) is an important vital parameter in neurointensive care. Currently, there is no non-invasive method for its measurement that can easily be applied at the bedside. A new tool to determine CBF is based on near-infrared spectroscopy (NIRS) applied together with indocyanine green (ICG) dye dilution. From a bilateral measurement on selected regions on the head of infrared (IR) absorption at various wavelengths during the dilution maneuver, the vascular perfusion characteristics of the two brain hemispheres can be determined in terms of mean transit time (mtt) of ICG, cerebral blood volume (CBV) and CBF.So far, on nine healthy volunteers, NIRS ICG dye dilution bihemispheric measurements were performed, which yielded to mtt given as median (range) of 9.3 s (5.1–16.3 s), CBV of 3.5 ml/100 g (1.7–4.1 ml/100 g), and CBF of 18.2 ml/(100 g×min) [11.1–48.6 ml/(100 g×min)]. Additionally, the blood flow index (BFI) was calculated with BFI= 13.8 mg/(100 g×s) [6.6–15.2 mg/(100 g×s)]. The Spearman rank correlation coefficient between CBF and BFI was RS = 0.76. However, as the Bland & Altman plot between CBFNIRS and the CBFBFI documents, the limits of agreement are rather wide (21.9±6.7). Under physiological conditions in healthy volunteers, no differences could be detected between the hemispheres.

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