Near-infrared spectroscopy and indocyanine green derived blood flow index for noninvasive measurement of muscle perfusion during exercise

2011 ◽  
Vol 2011 ◽  
pp. 127-129
Author(s):  
R.J. Shephard
Keyword(s):  
Blood Flow ◽  
Infrared Spectroscopy ◽  
Indocyanine Green ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Noninvasive Measurement ◽  
Flow Index ◽  
Muscle Perfusion ◽  
Blood Flow Index

scholarly journals Noninvasive Measurement of Regional Cerebral Blood Flow by Near-Infrared Spectroscopy and Indocyanine Green

1998 ◽  
Vol 18 (4) ◽  
pp. 445-456 ◽  
Author(s):  
Wolfgang M. Kuebler ◽  
Axel Sckell ◽  
Oliver Habler ◽  
Martin Kleen ◽  
Gerhard E. H. Kuhnle ◽  
...  
Keyword(s):  
Blood Flow ◽  
Infrared Spectroscopy ◽  
Indocyanine Green ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Calculated Data ◽  
Practical Method ◽  
Flow Index ◽  
Noninvasive Technique ◽  
Blood Flow Index

Clinicians lack a practical method for measuring CBF rapidly, repeatedly, and noninvasively at the bedside. A new noninvasive technique for estimation of cerebral hemodynamics by use of near-infrared spectroscopy (NIRS) and an intravenously infused tracer dye is proposed. Kinetics of the infrared tracer indocyanine green were monitored on the intact skull in pigs. According to an algorithm derived from fluorescein flowmetry, a relative blood flow index (BFI) was calculated. Data obtained were compared with cerebral and galeal blood flow values assessed by radioactive microspheres under baseline conditions and during hemorrhagic shock and resuscitation. Blood flow index correlated significantly ( rs = 0.814, P < 0.001) with cortical blood flow but not with galeal blood flow ( rs = 0.258). However, limits of agreement between BFI and CBF are rather wide (± 38.2 ± 6.4 mL 100 g−1 min−1) and require further studies. Data presented demonstrate that detection of tracer kinetics in the cerebrovasculature by NIRS may serve as valuable tool for the noninvasive estimation of regional CBF. Indocyanine green dilution curves monitored noninvasively on the intact skull by NIRS reflect dye passage through the cerebral, not extracerebral, circulation.

Near-infrared spectroscopy and indocyanine green derived blood flow index for noninvasive measurement of muscle perfusion during exercise

2010 ◽  
Vol 108 (4) ◽  
pp. 962-967 ◽  
Author(s):  
Helmut Habazettl ◽  
Dimitris Athanasopoulos ◽  
Wolfgang M. Kuebler ◽  
Harrieth Wagner ◽  
Charis Roussos ◽  
...  
Keyword(s):  
Blood Flow ◽  
Infrared Spectroscopy ◽  
Indocyanine Green ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Interobserver Variability ◽  
Concentration Curve ◽  
Flow Index ◽  
Blood Flow Index ◽  
Muscle Concentration

Near-infrared spectroscopy (NIRS) with the tracer indocyanine green (ICG) may be used for measuring muscle blood flow (MBF) during exercise, if arterial ICG concentration is measured simultaneously. Although pulse dye densitometry allows for noninvasive measurement of arterial dye concentration, this technique is sensitive to motion and may not be applicable during exercise. The aim of this study was to evaluate a noninvasive blood flow index (BFI), which is derived solely from the muscle ICG concentration curve. In 10 male cyclists 5 mg ICG were injected into an antecubital vein at rest and during cycling at 30, 60, 70, 80, 90, and 100% of previously determined maximal work load. Simultaneously blood was withdrawn through a photodensitometer at 20 ml/min from the radial artery to measure arterial ICG concentration. To measure muscle tissue ICG concentrations, two sets of NIRS optodes were positioned on the skin, one over the left seventh intercostal space and the other over the left vastus lateralis muscle. MBF was calculated from the arterial and muscle concentration data according to Fick's principle. BFI was calculated solely from the muscle concentration curve as ICG concentration difference divided by rise time between 10 and 90% of peak. During exercise mean BFI values changed similarly to MBF in both intercostal and quadriceps muscles and showed excellent correlations with MBF: r = 0.98 and 0.96, respectively. Individual data showed some scattering among BFI and MBF values but still reasonable correlations of BFI with MBF: r = 0.73 and 0.72 for intercostal and quadriceps muscles, respectively. Interobserver variability, as analyzed by Bland-Altman plots, was considerably less for BFI than MBF. These data suggest that BFI can be used for measuring changes in muscle perfusion from rest to maximal exercise. Although absolute blood flow cannot be determined, BFI has the advantages of being essentially noninvasive and having low interobserver variability.

scholarly journals Near-Infrared Spectroscopy Assessment of Cerebral Oxygen Metabolism in the Developing Premature Brain

2011 ◽  
Vol 32 (3) ◽  
pp. 481-488 ◽  
Author(s):  
Nadège Roche-Labarbe ◽  
Angela Fenoglio ◽  
Alpna Aggarwal ◽  
Mathieu Dehaes ◽  
Stefan A Carp ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Correlation Spectroscopy ◽  
Chronological Age ◽  
Flow Index ◽  
P Value ◽  
Blood Flow Index

Little is known about cerebral blood flow, cerebral blood volume (CBV), oxygenation, and oxygen consumption in the premature newborn brain. We combined quantitative frequency-domain near-infrared spectroscopy measures of cerebral hemoglobin oxygenation (SO2) and CBV with diffusion correlation spectroscopy measures of cerebral blood flow index (BFix) to determine the relationship between these measures, gestational age at birth (GA), and chronological age. We followed 56 neonates of various GA once a week during their hospital stay. We provide absolute values of SO2 and CBV, relative values of BFix, and relative cerebral metabolic rate of oxygen (rCMRO2) as a function of postmenstrual age (PMA) and chronological age for four GA groups. SO2 correlates with chronological age ( r=−0.54, P value 0.001) but not with PMA ( r=−0.07), whereas BFix and rCMRO2 correlate better with PMA ( r=0.37 and 0.43, respectively, P value 0.001). Relative CMRO2 during the first month of life is lower when GA is lower. Blood flow index and rCMRO2 are more accurate biomarkers of the brain development than SO2 in the premature newborns.

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.

Sign in / Sign up

Export Citation Format

Share Document