scholarly journals Functional interferometric diffusing wave spectroscopy of the human brain

2021 ◽  
Vol 7 (20) ◽  
pp. eabe0150
Author(s):  
Wenjun Zhou ◽  
Oybek Kholiqov ◽  
Jun Zhu ◽  
Mingjun Zhao ◽  
Lara L. Zimmermann ◽  
...  
Keyword(s):  
Blood Flow ◽  
Near Infrared ◽  
Continuous Wave ◽  
Brain Activity ◽  
Low Cost ◽  
Infrared Light ◽  
Flow Index ◽  
Diffusing Wave Spectroscopy ◽  
Detector Arrays ◽  
Blood Flow Index

Cerebral blood flow (CBF) is essential for brain function, and CBF-related signals can inform us about brain activity. Yet currently, high-end medical instrumentation is needed to perform a CBF measurement in adult humans. Here, we describe functional interferometric diffusing wave spectroscopy (fiDWS), which introduces and collects near-infrared light via the scalp, using inexpensive detector arrays to rapidly monitor coherent light fluctuations that encode brain blood flow index (BFI), a surrogate for CBF. Compared to other functional optical approaches, fiDWS measures BFI faster and deeper while also providing continuous wave absorption signals. Achieving clear pulsatile BFI waveforms at source-collector separations of 3.5 cm, we confirm that optical BFI, not absorption, shows a graded hypercapnic response consistent with human cerebrovascular physiology, and that BFI has a better contrast-to-noise ratio than absorption during brain activation. By providing high-throughput measurements of optical BFI at low cost, fiDWS will expand access to CBF.

Blood Flow Index Using Near Infrared Spectroscopy and Indocyanine Green Dye as a Minimally Invasive Method for Assessing Respiratory Muscle Blood Flow in Humans

CHEST Journal ◽  
2010 ◽  
Vol 138 (4) ◽  
pp. 917A
Author(s):  
Jordan A. Guenette ◽  
William R. Henderson ◽  
Paolo B. Dominelli ◽  
Jordan S. Querido ◽  
Donald E. Griesdale ◽  
...  
Keyword(s):  
Blood Flow ◽  
Infrared Spectroscopy ◽  
Minimally Invasive ◽  
Respiratory Muscle ◽  
Near Infrared ◽  
Muscle Blood Flow ◽  
Flow Index ◽  
Indocyanine Green Dye ◽  
Blood Flow Index ◽  
Invasive Method

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.

scholarly journals MON-488 Technologies of Diffuse Optics in the Diagnosis of Thyroid Cancer

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Gloria Beatriz Aranda Velazquez ◽  
Giuseppe Lo Presti ◽  
Lorenzo Cortese ◽  
Davide Contini ◽  
Alberto Dalla Mora ◽  
...  
Keyword(s):  
Blood Flow ◽  
Thyroid Cancer ◽  
Near Infrared ◽  
Thyroid Nodules ◽  
Microvascular Blood Flow ◽  
Flow Index ◽  
Diffuse Optics ◽  
Significant Difference ◽  
Blood Flow Index ◽  
The Difference

Abstract BACKGROUND: The most common tool to test malignancy in the study of thyroid nodules (NT) is ultrasound and fine needle aspiration biopsy (FNAB). However, the sensitivity and specificity of the method and the effectiveness in thyroid cancer are limited; therefore new methods to study thyroid nodules are required. In this way our goal is to introduce hybrid diffuse optical instruments that are capable to measure and discriminate altered microvascular blood flow, blood volume and tissue scattering coefficients of TN. Near-infrared diffuse optical technologies aim to overcome the shortcomings of present techniques while screening for malignant thyroid nodules for early and fast diagnosis of cancer. This idea was based on the previous experience in breast cancers with diffuse optical techniques. METHODS: We have developed a device based on near-infrared diffuse correlation spectroscopy (DCS), which is a technology aimed at retrieving the microvascular flow of a certain region of tissue by mean of low power near-infrared laser light, and used in combination with a commercial ultrasound system (US). In order to combine these devices, we have developed a probe enabling multimodal data acquisition and subsequently we have analyzed the optical properties and the blood flow index in the thyroid lobes of eleven subjects who presented a thyroid nodule. RESULTS: Four subjects have required FNAB: P4 and P7 were reported as being malignant (Bethesda VI and IV respectively) while P6 and P8 were evaluated as being benign (Bethesda II). Surgical removal confirmed papillary thyroid carcinoma in P4, while denied the result of FNAB for P7 (Multinodular thyroid hyperplasia). We have considered the contralateral lobe as intra-subject reference to validate the feasibility of the DCS system in a very absorbing tissue as thyroid is. The difference between the blood flow index of the nodule and the contralateral lobe is maximum for subject P4, while the difference in benign subjects is lower. T-test showed no significant difference between benign nodules and contralateral lobes. Subject P7 showed a small difference as for other benign subjects despite the FNAB results indicating presence of malignancy. CONCLUSION: Apparently diffuse optics technologies would be able to differentiate malignant thyroid nodules from benign thyroid nodules, but more measurements require confirming our preliminary results as that diffuse optical technology can complement the current techniques such as US and FNAB. A new measurement campaign is being scheduled with a completed, fully integrated device that was developed within the LUCA project (http://www.luca-project.eu).

Blood flow index using near-infrared spectroscopy and indocyanine green as a minimally invasive tool to assess respiratory muscle blood flow in humans

2011 ◽  
Vol 300 (4) ◽  
pp. R984-R992 ◽  
Author(s):  
Jordan A. Guenette ◽  
William R. Henderson ◽  
Paolo B. Dominelli ◽  
Jordan S. Querido ◽  
Penelope M. Brasher ◽  
...  
Keyword(s):  
Blood Flow ◽  
Infrared Spectroscopy ◽  
Respiratory Muscle ◽  
Near Infrared ◽  
Muscle Blood Flow ◽  
Work Of Breathing ◽  
Respiratory Muscles ◽  
Flow Index ◽  
Arterial Cannulation ◽  
Blood Flow Index

Near-infrared spectroscopy (NIRS) in combination with indocyanine green (ICG) dye has recently been used to measure respiratory muscle blood flow (RMBF) in humans. This method is based on the Fick principle and is determined by measuring ICG in the respiratory muscles using transcutaneous NIRS in relation to the [ICG] in arterial blood as measured using photodensitometry. This method is invasive since it requires arterial cannulation, repeated blood withdrawals, and reinfusions. A less invasive alternative is to calculate a relative measure of blood flow known as the blood flow index (BFI), which is based solely on the NIRS ICG curve, thus negating the need for arterial cannulation. Accordingly, the purpose of this study was to determine whether BFI can be used to measure RMBF at rest and during voluntary isocapnic hyperpnea at 25, 40, 55, and 70% of maximal voluntary ventilation in seven healthy humans. BFI was calculated as the change in maximal [ICG] divided by the rise time of the NIRS-derived ICG curve. Intercostal and sternocleidomastoid muscle BFI were correlated with simultaneously measured work of breathing and electromyography (EMG) data from the same muscles. BFI showed strong relationships with the work of breathing and EMG for both respiratory muscles. The coefficients of determination ( R2) comparing BFI vs. the work of breathing for the intercostal and sternocleidomastoid muscles were 0.887 ( P < 0.001) and 0.863 ( P < 0.001), respectively, whereas the R2 for BFI vs. EMG for the intercostal and sternocleidomastoid muscles were 0.879 ( P < 0.001) and 0.930 ( P < 0.001), respectively. These data suggest that the BFI closely reflects RMBF in conscious humans across a wide range of ventilations and provides a less invasive and less technically demanding alternative to measuring RMBF.

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.

Sign in / Sign up

Export Citation Format

Share Document