Quantification of adult cerebral hemodynamics by near-infrared spectroscopy

1994 ◽  
Vol 77 (6) ◽  
pp. 2753-2760 ◽  
Author(s):  
C. E. Elwell ◽  
M. Cope ◽  
A. D. Edwards ◽  
J. S. Wyatt ◽  
D. T. Delpy ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Cerebral Hemodynamics ◽  
Arterial Oxygen ◽  
The Mean

Near-infrared spectroscopy was used to measure global cerebral blood flow and volume in 10 healthy adult volunteers. High- and low-cerebral blood flow compartments were detected with mean flows for all 10 subjects of 59 +/- 21 (SD) and 11 +/- 4 ml.100 g-1.min-1, respectively. The mean cerebral blood volume of the group was 2.85 +/- 0.97 ml/100 g. Analysis of spontaneous changes in the cerebral concentrations of oxyhemoglobin and deoxyhemoglobin demonstrated strong correlations between respiratory rate and the oscillation frequency of cerebral oxyhemoglobin concentration (r = 0.99) and arterial oxygen saturation (SaO2) (r = 0.99). An estimate of the mean cerebral oxygen saturation for all subjects averaged 59.4 +/- 12.4% when their mean SaO2 was 91.8 +/- 2.4% (equivalent to 67.6 +/- 13.8% at a normoxic SaO2 of 98%). These results demonstrate that near-infrared spectroscopy can be used as a noninvasive bedside technique for both qualitative and quantitative evaluation of cerebral hemodynamics and oxygenation in adults.

scholarly journals Brain oxygen saturation assessment in neonates using T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy

2016 ◽  
Vol 37 (3) ◽  
pp. 902-913 ◽  
Author(s):  
Thomas Alderliesten ◽  
Jill B De Vis ◽  
Petra MA Lemmers ◽  
Jeroen Hendrikse ◽  
Floris Groenendaal ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Magnetic Resonance ◽  
Oxygen Saturation ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Sagittal Sinus ◽  
Venous Oxygen Saturation ◽  
Blood Imaging

Although near-infrared spectroscopy is increasingly being used to monitor cerebral oxygenation in neonates, it has a limited penetration depth. The T2-prepared Blood Imaging of Oxygen Saturation (T2-BIOS) magnetic resonance sequence provides an oxygen saturation estimate on a voxel-by-voxel basis, without needing a respiratory calibration experiment. In 15 neonates, oxygen saturation measured by T2-prepared blood imaging of oxygen saturation and near-infrared spectroscopy were compared. In addition, these measures were compared to cerebral blood flow and venous oxygen saturation in the sagittal sinus. A strong linear relation was found between the oxygen saturation measured by magnetic resonance imaging and the oxygen saturation measured by near-infrared spectroscopy ( R2 = 0.64, p < 0.001). Strong linear correlations were found between near-infrared spectroscopy oxygen saturation, and magnetic resonance imaging measures of frontal cerebral blood flow, whole brain cerebral blood flow and venous oxygen saturation in the sagittal sinus ( R2 = 0.71, 0.50, 0.65; p < 0.01). The oxygen saturation obtained by T2-prepared blood imaging of oxygen saturation correlated with venous oxygen saturation in the sagittal sinus ( R2 = 0.49, p = 0.023), but no significant correlations could be demonstrated with frontal and whole brain cerebral blood flow. These results suggest that measuring oxygen saturation by T2-prepared blood imaging of oxygen saturation is feasible, even in neonates. Strong correlations between the various methods work as a cross validation for near-infrared spectroscopy and T2-prepared blood imaging of oxygen saturation, confirming the validity of using of these techniques for determining cerebral oxygenation.

Report of the National Institute of Neurological Disorders and Stroke Workshop on Near Infrared Spectroscopy

PEDIATRICS ◽  
1993 ◽  
Vol 91 (2) ◽  
pp. 414-417
Author(s):  
Deborah G. Hirtz
Keyword(s):  
Blood Flow ◽  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Cytochrome Oxidase ◽  
Near Infrared Spectroscopy ◽  
Neurological Disorders ◽  
Near Infrared ◽  
Arterial Oxygen ◽  
Infrared Range ◽  
Near Infrared Range

A workshop about near infrared spectroscopy (NIRS), an emerging technology used to measure cerebral oxygenation and blood flow, was sponsored by the Developmental Neurology Branch, Division of Convulsive, Developmental, and Neuromuscular Disorders of the National Institute of Neurological Disorders and Stroke in Bethesda, MD, on March 31 and April 1, 1992. This was an international work-shop designed to bring together experts in the development of this technology with clinical researchers. Topics covered included the history and background of the development of NIRS technology, experimental models for the use of NIRS, clinical experience with NIRS in the neonate and the intrapartum fetus, and current key research issues with regard to technology and clinical use. THE TECHNOLOGY Near infrared spectroscopy is a new application of an existing technology which can provide information about changes in cerebral oxygen saturation, cerebral blood flow and volume, and oxygen utilization in the brain. The technology has been used for a long time to monitor hemoglobin, but only more recently for cytochrome oxidase. It involves the same basic principle used in the pulse oximeter, which uses light in the visible range to detect changes in finger arterial oxygen saturation. The method is based on the fact that light in the near infrared range (700 to 1000 nm) can pass through skin, bone, and other tissues relatively easily and that there are characteristic absorption bands of oxygenated and deoxygenated hemoglobin, and of the mitochondrial enzyme cytochrome oxidase (or cytochrome AA3) in the near infrared range. When the near infrared beam is passed through tissue, a decrease in signal intensity results from the absorbance of the chromophores in the medium.

Arterial and Venous Contributions to Near-infrared Cerebral Oximetry

2000 ◽  
Vol 93 (4) ◽  
pp. 947-953 ◽  
Author(s):  
H. Marc Watzman ◽  
C. Dean Kurth ◽  
Lisa M. Montenegro ◽  
Jonathan Rome ◽  
James M. Steven ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Frequency Domain ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Fixed Ratio ◽  
Cerebral Oximetry ◽  
Infrared Light ◽  
Arterial Oxygen

Background Cerebral oximetry is a noninvasive bedside technology using near-infrared light to monitor cerebral oxygen saturation (Sco2) in an uncertain mixture of arteries, capillaries, and veins. The present study used frequency domain near-infrared spectroscopy to determine the ratio of arterial and venous blood monitored by cerebral oximetry during normoxia, hypoxia, and hypocapnia. Methods Twenty anesthetized children aged &lt; 8 yr with congenital heart disease of varying arterial oxygen saturation (Sao2) were studied during cardiac catheterization. Sco2, Sao2, and jugular bulb oxygen saturation (Sjo2) were measured by frequency domain near-infrared spectroscopy and blood oximetry at normocapnia room air, normocapnia 100% inspired O2, and hypocapnia room air. Results Among subject conditions, Sao2 ranged from 68% to 100%, Sjo2 from 27% to 96%, and Sco2 from 29% to 92%. Sco2 was significantly related to Sao2 (y = 0. 85 x -17, r = 0.47), Sjo2 (y = 0.77 x +13, r = 0.70), and the combination (Sco2 = 0.46 Sao2 + 0.56 Sjo2 - 17, R = 0.71). The arterial and venous contribution to cerebral oximetry was 16 +/- 21% and 84 +/- 21%, respectively (where Sco2 = alpha Sao2 + beta Sjo2 with alpha and beta being arterial and venous contributions). The contribution was similar among conditions but differed significantly among subjects (range, approximately 40:60 to approximately 0:100, arterial:venous). Conclusions Cerebral oximetry monitors an arterial/venous ratio of 16:84, similar in normoxia, hypoxia, and hypocapnia. Because of biologic variation in cerebral arterial/venous ratios, use of a fixed ratio is not a good method to validate the technology.

scholarly journals Cerebral perfusion and oxygenation are impaired by folate deficiency in rat: Absolute measurements with noninvasive near-infrared spectroscopy

2011 ◽  
Vol 31 (6) ◽  
pp. 1482-1492 ◽  
Author(s):  
Bertan Hallacoglu ◽  
Angelo Sassaroli ◽  
Sergio Fantini ◽  
Aron M Troen
Keyword(s):  
Cognitive Impairment ◽  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Arterial Oxygen Saturation ◽  
Hemoglobin Concentration ◽  
Microvascular Dysfunction ◽  
Common Finding ◽  
Arterial Oxygen

Brain microvascular pathology is a common finding in Alzheimer's disease and other dementias. However, the extent to which microvascular abnormalities cause or contribute to cognitive impairment is unclear. Noninvasive near-infrared spectroscopy (NIRS) can address this question, but its use for clarifying the role of microvascular dysfunction in dementia has been limited due to theoretical and practical considerations. We developed a new noninvasive NIRS method to obtain quantitative, dynamic measurements of absolute brain hemoglobin concentration and oxygen saturation and used it to show significant cerebrovascular impairments in a rat model of diet-induced vascular cognitive impairment. We fed young rats folate-deficient (FD) and control diets and measured absolute brain hemoglobin and hemodynamic parameters at rest and during transient mild hypoxia and hypercapnia. With respect to control animals, FD rats featured significantly lower brain hemoglobin concentration (72±4 μmol/L versus 95±6 μmol/L) and oxygen saturation (54%±3% versus 65%±2%). By contrast, resting arterial oxygen saturation was the same for both groups (96%±4%), indicating that decrements in brain hemoglobin oxygenation were independent of blood oxygen carrying capacity. Vasomotor reactivity in response to hypercapnia was also impaired in FD rats. Our results implicate microvascular abnormality and diminished oxygen delivery as a mechanism of cognitive impairment.

scholarly journals Changes in cerebral oxygen saturation and cerebral blood flow velocity under mild +Gz hypergravity

2019 ◽  
Vol 127 (1) ◽  
pp. 190-197 ◽  
Author(s):  
Toru Konishi ◽  
Takuya Kurazumi ◽  
Tomokazu Kato ◽  
Chiharu Takko ◽  
Yojiro Ogawa ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Oxygen Saturation ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Cerebral Oxygen Saturation ◽  
Cerebral Oxygen ◽  
Regional Cerebral Oxygen Saturation

We previously reported that cerebral blood flow (CBF) was reduced by even mild +Gz hypergravity. Regional cerebral oxygen saturation as measured by near-infrared spectroscopy (C-rSO2) has been widely used to detect cerebral ischemia in clinical practice. For example, decreases in C-rSO2reflect reduced CBF or arterial oxygen saturation. Thus it was hypothesized that C-rSO2would decrease in association with reduced CBF during mild hypergravity. To test this hypothesis, we measured CBF velocity by transcranial Doppler ultrasonography and C-rSO2during mild +Gz hypergravity while participants were in a sitting position. Among 17 male participants, 15 completed 21 min of exposure to +1.5 Gz generated by short-arm centrifuge. C-rSO2and mean CBF velocity in the middle cerebral artery (MCBFVMCA) during centrifugation were averaged every 5 min and compared with pre-hypergravity (+1.0 Gz). C-rSO2did not change significantly throughout centrifugation, although MCBFVMCAgradually decreased from the beginning (−1.2% at 0–5 min), and significantly decreased at 5–10 min (−4.8%), 10–15 min (−6.7%), and 15–20 min (−7.4%). Contrary to our hypothesis, decreases in C-rSO2were not detected, despite reductions in CBF velocity during hypergravity. Since some assumptions, such as unaltered arteriovenous volume ratio, hemoglobin concentration, extracranial blood flow, and brain activity, need to be satisfied to monitor cerebral ischemia by C-rSO2, the present results suggest that these necessary assumptions for near-infrared spectroscopy are not always applicable, and that cerebral oxygenation may not precisely reflect decreases in CBF under mild +Gz hypergravity.NEW & NOTEWORTHY To our knowledge, this is the first study to evaluate simultaneously cerebral oxygenation monitored by near-infrared spectroscopy and cerebral blood flow (CBF) monitored by transcranial Doppler under +1.5 Gz hypergravity. Contrary to our hypothesis, there was no significant correlation between CBF velocity and regional cerebral oxygen saturation (C-rSO2). However, an incomplete case nearly involving syncope suggests the possibility that C-rSO2can detect a remarkable decrease in CBF with development of presyncope during +Gz hypergravity.

scholarly journals Near-infrared spectroscopy measurements of cerebral blood flow and oxygen consumption following hypoxia-ischemia in newborn piglets

2006 ◽  
Vol 100 (3) ◽  
pp. 850-857 ◽  
Author(s):  
Kenneth M. Tichauer ◽  
Derek W. Brown ◽  
Jennifer Hadway ◽  
Ting-Yim Lee ◽  
Keith St. Lawrence
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Neonatal Intensive Care ◽  
Near Infrared ◽  
Hemoglobin Concentration ◽  
Oxygen Extraction Fraction ◽  
Newborn Piglets ◽  
Hypoxia Ischemia

Impaired oxidative metabolism following hypoxia-ischemia (HI) is believed to be an early indicator of delayed brain injury. The cerebral metabolic rate of oxygen (CMRO2) can be measured by combining near-infrared spectroscopy (NIRS) measurements of cerebral blood flow (CBF) and cerebral deoxy-hemoglobin concentration. The ability of NIRS to measure changes in CMRO2 following HI was investigated in newborn piglets. Nine piglets were subjected to 30 min of HI by occluding both carotid arteries and reducing the fraction of inspired oxygen to 8%. An additional nine piglets served as sham-operated controls. Measurements of CBF, oxygen extraction fraction (OEF), and CMRO2 were obtained at baseline and at 6 h after the HI insult. Of the three parameters, only CMRO2 showed a persistent and significant change after HI. Five minutes after reoxygenation, there was a 28 ± 12% (mean ± SE) decrease in CMRO2, a 72 ± 50% increase in CBF, and a 56 ± 19% decrease in OEF compared with baseline ( P < 0.05). By 30 min postinsult and for the remainder of the study, there were no significant differences in CBF and OEF between control and insult groups, whereas CMRO2 remained depressed throughout the 6-h postinsult period. This study demonstrates that NIRS can measure decreases in CMRO2 caused by HI. The results highlight the potential for NIRS to be used in the neonatal intensive care unit to detect delayed brain damage.

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