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Liu X, Mohtasebi M, Safavi P, Fathi F, Haratbar SR, Chen L, Chen J, Bada HS, Chen L, Abu Jawdeh EG, Yu G. Wearable fiber-free optical sensor for continuous monitoring of neonatal cerebral blood flow and oxygenation. Pediatr Res 2024:10.1038/s41390-024-03137-z. [PMID: 38503982 DOI: 10.1038/s41390-024-03137-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 02/15/2024] [Accepted: 03/01/2024] [Indexed: 03/21/2024]
Abstract
BACKGROUND Unstable cerebral hemodynamics places preterm infants at high risk of brain injury. We adapted an innovative, fiber-free, wearable diffuse speckle contrast flow-oximetry (DSCFO) device for continuous monitoring of both cerebral blood flow (CBF) and oxygenation in neonatal piglets and preterm infants. METHODS DSCFO uses two small laser diodes as focused-point and a tiny CMOS camera as a high-density two-dimensional detector to detect spontaneous spatial fluctuation of diffuse laser speckles for CBF measurement, and light intensity attenuations for cerebral oxygenation measurement. The DSCFO was first validated against the established diffuse correlation spectroscopy (DCS) in neonatal piglets and then utilized for continuous CBF and oxygenation monitoring in preterm infants during intermittent hypoxemia (IH) events. RESULTS Significant correlations between the DSCFO and DCS measurements of CBF variations in neonatal piglets were observed. IH events induced fluctuations in CBF, cerebral oxygenation, and peripheral cardiorespiratory vitals in preterm infants. However, no consistent correlation patterns were observed among peripheral and cerebral monitoring parameters. CONCLUSIONS This pilot study demonstrated the feasibility of DSCFO technology to serve as a low-cost wearable sensor for continuous monitoring of multiple cerebral hemodynamic parameters. The results suggested the importance of multi-parameter measurements for understanding deep insights of peripheral and cerebral regulations. IMPACT The innovative DSCFO technology may serve as a low-cost wearable sensor for continuous bedside monitoring of multiple cerebral hemodynamic parameters in neonatal intensive care units. Concurrent DSCFO and DCS measurements of CBF variations in neonatal piglet models generated consistent results. No consistent correlation patterns were observed among peripheral and cerebral monitoring parameters in preterm neonates, suggesting the importance of multi-parameter measurements for understanding deep insights of peripheral and cerebral regulations during IH events. Integrating and correlating multiple cerebral functional parameters with clinical outcomes may identify biomarkers for prediction and management of IH associated brain injury.
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Affiliation(s)
- Xuhui Liu
- Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA
| | - Mehrana Mohtasebi
- Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA
| | - Pegah Safavi
- Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA
| | - Faraneh Fathi
- Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA
| | | | - Li Chen
- Biostatistics and Bioinformatics Shared Resource Facility, Markey Cancer Center, University of Kentucky, Lexington, KY, USA
| | - Jin Chen
- Department of Internal Medicine and Department of Computer Science, Institute for Biomedical Informatics, University of Kentucky, Lexington, KY, USA
| | - Henrietta S Bada
- Division of Neonatology, Department of Pediatrics, University of Kentucky, Lexington, KY, USA
| | - Lei Chen
- Department of Physiology and the Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, USA
| | - Elie G Abu Jawdeh
- Division of Neonatology, Department of Pediatrics, University of Kentucky, Lexington, KY, USA
| | - Guoqiang Yu
- Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA.
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Li NC, Ioussoufovitch S, Diop M. HyperTRCSS: A hyperspectral time-resolved compressive sensing spectrometer for depth-sensitive monitoring of cytochrome-c-oxidase and blood oxygenation. JOURNAL OF BIOMEDICAL OPTICS 2024; 29:015002. [PMID: 38269084 PMCID: PMC10807872 DOI: 10.1117/1.jbo.29.1.015002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 12/21/2023] [Accepted: 01/04/2024] [Indexed: 01/26/2024]
Abstract
Significance Hyperspectral time-resolved (TR) near-infrared spectroscopy offers the potential to monitor cytochrome-c-oxidase (oxCCO) and blood oxygenation in the adult brain with minimal scalp/skull contamination. We introduce a hyperspectral TR spectrometer that uses compressive sensing to minimize acquisition time without compromising spectral range or resolution and demonstrate oxCCO and blood oxygenation monitoring in deep tissue. Aim Develop a hyperspectral TR compressive sensing spectrometer and use it to monitor oxCCO and blood oxygenation in deep tissue. Approach Homogeneous tissue-mimicking phantom experiments were conducted to confirm the spectrometer's sensitivity to oxCCO and blood oxygenation. Two-layer phantoms were used to evaluate the spectrometer's sensitivity to oxCCO and blood oxygenation in the bottom layer through a 10 mm thick static top layer. Results The spectrometer was sensitive to oxCCO and blood oxygenation changes in the bottom layer of the two-layer phantoms, as confirmed by concomitant measurements acquired directly from the bottom layer. Measures of oxCCO and blood oxygenation by the spectrometer were highly correlated with "gold standard" measures in the homogeneous and two-layer phantom experiments. Conclusions The results show that the hyperspectral TR compressive sensing spectrometer is sensitive to changes in oxCCO and blood oxygenation in deep tissue through a thick static top layer.
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Affiliation(s)
- Natalie C. Li
- Western University, School of Biomedical Engineering, Faculty of Engineering, London, Ontario, Canada
| | - Seva Ioussoufovitch
- Western University, School of Biomedical Engineering, Faculty of Engineering, London, Ontario, Canada
| | - Mamadou Diop
- Western University, School of Biomedical Engineering, Faculty of Engineering, London, Ontario, Canada
- Western University, Schulich School of Medicine and Dentistry, Department of Medical Biophysics, London, Ontario, Canada
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
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Qi Y, Lin Z, Lu H, Mao J, Zhang H, Zhao P, Hou Y. Cerebral Hemodynamic and Metabolic Abnormalities in Neonatal Hypocalcemia: Findings from Advanced MRI. AJNR Am J Neuroradiol 2023; 44:1224-1230. [PMID: 37709354 PMCID: PMC10549950 DOI: 10.3174/ajnr.a7994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/16/2023] [Indexed: 09/16/2023]
Abstract
BACKGROUND AND PURPOSE Neonatal hypocalcemia is the most common metabolic disorder, and whether asymptomatic disease should be treated with calcium supplements remains controversial. We aimed to quantify neonatal hypocalcemia's global CBF and cerebral metabolic rate of oxygen (CMRO2) using physiologic MR imaging and elucidate the pathophysiologic vulnerabilities of neonatal hypocalcemia. MATERIALS AND METHODS A total of 37 consecutive patients with neonatal hypocalcemia were enrolled. They were further divided into subgroups with and without structural MR imaging abnormalities, denoted as neonatal hypocalcemia-a (n = 24) and neonatal hypocalcemia-n (n = 13). Nineteen healthy neonates were enrolled as a control group. Brain physiologic parameters determined using phase-contrast MR imaging, T2-relaxation-under-spin-tagging MR imaging, and brain volume were compared between patients with neonatal hypocalcemia (their subgroups) and controls. Predictors for neonatal hypocalcemia-related brain injuries were identified using multivariate logistic regression analysis and expressed as ORs with 95% CIs. RESULTS Patients with neonatal hypocalcemia showed significantly lower CBF and CMRO2 compared with controls. Furthermore, the neonatal hypocalcemia-a subset (versus controls or neonatal hypocalcemia-n) had significantly lower CBF and CMRO2. There was no obvious difference in CBF and CMRO2 between the neonatal hypocalcemia-n subset and controls. CBF and CMRO2 were independently associated with neonatal hypocalcemia. The ORs were 0.80 (95% CI, 0.65-0.99) and 0.97 (95% CI, 0.89-1.05) for CBF and CMRO2, respectively. CONCLUSIONS Neonatal hypocalcemia with structural damage may exhibit lower hemodynamics and cerebral metabolism. CBF may be useful in assessing the need for calcium supplementation in asymptomatic neonatal hypocalcemia to prevent brain injury.
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Affiliation(s)
- Ying Qi
- From the Department of Radiology (Y.Q., H.Z., Y.H.), Shengjing Hospital of China Medical University, Shenyang, China
| | - Zixuan Lin
- Key Laboratory for Biomedical Engineering of Ministry of Education (Z.L.), Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China
| | - Hanzhang Lu
- Department of Radiology (H.L.), Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jian Mao
- Department of Pediatrics (J.M.), Shengjing Hospital of China Medical University, Shenyang, China
| | - Hongyang Zhang
- From the Department of Radiology (Y.Q., H.Z., Y.H.), Shengjing Hospital of China Medical University, Shenyang, China
| | - Pengfei Zhao
- Department of Pharmacology (P.Z.), School of Pharmaceutical Sciences, China Medical University, Shenyang, China
| | - Yang Hou
- From the Department of Radiology (Y.Q., H.Z., Y.H.), Shengjing Hospital of China Medical University, Shenyang, China
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4
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Liu X, Mohtasebi M, Safavi P, Fathi F, Haratbar SR, Chen L, Chen J, Bada HS, Chen L, Abu Jawdeh EG, Yu G. A Wearable Fiber-Free Optical Sensor for Continuous Monitoring of Neonatal Cerebral Blood Flow and Oxygenation. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.09.21.23295914. [PMID: 37790418 PMCID: PMC10543216 DOI: 10.1101/2023.09.21.23295914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Impact The innovative DSCFO technology may serve as a low-cost wearable sensor for continuous bedside monitoring of multiple cerebral hemodynamic parameters in neonatal intensive care units.Concurrent DSCFO and DCS measurements of CBF variations in neonatal piglet models generated consistent results.No consistent correlation patterns were observed among peripheral and cerebral monitoring parameters in preterm neonates, suggesting the importance of multi-parameter measurements for understanding deep insights of peripheral and cerebral regulations during IH events.Integrating and correlating multiple cerebral functional parameters with clinical outcomes may identify biomarkers for prediction and management of IH associated brain injury. Background Unstable cerebral hemodynamics places preterm infants at high risk of brain injury. We adapted an innovative, fiber-free, wearable diffuse speckle contrast flow-oximetry (DSCFO) device for continuous monitoring of both cerebral blood flow (CBF) and oxygenation in neonatal piglets and preterm infants. Methods DSCFO uses two small laser diodes as focused-point and a tiny CMOS camera as a high-density two-dimensional detector to detect spontaneous spatial fluctuation of diffuse laser speckles for CBF measurement, and light intensity attenuations for cerebral oxygenation measurement. The DSCFO was first validated against the established diffuse correlation spectroscopy (DCS) in neonatal piglets and then utilized for continuous CBF and oxygenation monitoring in preterm infants during intermittent hypoxemia (IH) events. Results Consistent results between the DSCFO and DCS measurements of CBF variations in neonatal piglets were observed. IH events induced fluctuations in CBF, cerebral oxygenation, and peripheral cardiorespiratory vitals in preterm infants. However, no consistent correlation patterns were observed among peripheral and cerebral monitoring parameters. Conclusions This pilot study demonstrated the feasibility of DSCFO technology to serve as a low-cost wearable sensor for continuous monitoring of multiple cerebral hemodynamic parameters. The results suggested the importance of multi-parameter measurements for understanding deep insights of peripheral and cerebral regulations.
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Ko TS, Catennacio E, Shin SS, Stern J, Massey SL, Kilbaugh TJ, Hwang M. Advanced Neuromonitoring Modalities on the Horizon: Detection and Management of Acute Brain Injury in Children. Neurocrit Care 2023; 38:791-811. [PMID: 36949362 PMCID: PMC10241718 DOI: 10.1007/s12028-023-01690-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 01/31/2023] [Indexed: 03/24/2023]
Abstract
Timely detection and monitoring of acute brain injury in children is essential to mitigate causes of injury and prevent secondary insults. Increasing survival in critically ill children has emphasized the importance of neuroprotective management strategies for long-term quality of life. In emergent and critical care settings, traditional neuroimaging modalities, such as computed tomography and magnetic resonance imaging (MRI), remain frontline diagnostic techniques to detect acute brain injury. Although detection of structural and anatomical abnormalities remains crucial, advanced MRI sequences assessing functional alterations in cerebral physiology provide unique diagnostic utility. Head ultrasound has emerged as a portable neuroimaging modality for point-of-care diagnosis via assessments of anatomical and perfusion abnormalities. Application of electroencephalography and near-infrared spectroscopy provides the opportunity for real-time detection and goal-directed management of neurological abnormalities at the bedside. In this review, we describe recent technological advancements in these neurodiagnostic modalities and elaborate on their current and potential utility in the detection and management of acute brain injury.
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Affiliation(s)
- Tiffany S Ko
- Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, USA.
| | - Eva Catennacio
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Samuel S Shin
- Department of Neurosurgery, Hospital of the University of Pennsylvania, Philadelphia, USA
| | - Joseph Stern
- Department of Radiology, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, USA
| | - Shavonne L Massey
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Todd J Kilbaugh
- Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Misun Hwang
- Department of Radiology, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, USA
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Milej D, Rajaram A, Suwalski M, Morrison LB, Shoemaker LN, St. Lawrence K. Assessing the relationship between the cerebral metabolic rate of oxygen and the oxidation state of cytochrome-c-oxidase. NEUROPHOTONICS 2022; 9:035001. [PMID: 35874144 PMCID: PMC9298853 DOI: 10.1117/1.nph.9.3.035001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 06/22/2022] [Indexed: 05/07/2023]
Abstract
Significance: Hyperspectral near-infrared spectroscopy (hsNIRS) combined with diffuse correlation spectroscopy (DCS) provides a noninvasive approach for monitoring cerebral blood flow (CBF), the cerebral metabolic rate of oxygen ( CMRO 2 ) and the oxidation state of cytochrome-c-oxidase (oxCCO). CMRO 2 is calculated by combining tissue oxygen saturation ( S t O 2 ) with CBF, whereas oxCCO can be measured directly by hsNIRS. Although both reflect oxygen metabolism, a direct comparison has yet to be studied. Aim: We aim to investigate the relationship between CMRO 2 and oxCCO during periods of restricted oxygen delivery and lower metabolic demand. Approach: A hybrid hsNIRS/DCS system was used to measure hemodynamic and metabolic responses in piglets exposed to cerebral ischemia and anesthetic-induced reductions in brain activity. Results: Although a linear relationship was observed between CMRO 2 and oxCCO during ischemia, both exhibited a nonlinear relationship with respect to CBF. In contrast, linear correlation was sufficient to characterize the relationships between CMRO 2 and CBF and between the two metabolic markers during reduced metabolic demand. Conclusions: The observed relationship between CMRO 2 and oxCCO during periods of restricted oxygen delivery and lower metabolic demand indicates that the two metabolic markers are strongly correlated.
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Affiliation(s)
- Daniel Milej
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
- Address all correspondence to Daniel Milej,
| | - Ajay Rajaram
- Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Marianne Suwalski
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
| | - Laura B. Morrison
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - Leena N. Shoemaker
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
- Western University, Department of Kinesiology, London, Ontario, Canada
| | - Keith St. Lawrence
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
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7
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Assessing cerebral blood flow, oxygenation and cytochrome c oxidase stability in preterm infants during the first 3 days after birth. Sci Rep 2022; 12:181. [PMID: 34996949 PMCID: PMC8741949 DOI: 10.1038/s41598-021-03830-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 12/02/2021] [Indexed: 02/07/2023] Open
Abstract
A major concern with preterm birth is the risk of neurodevelopmental disability. Poor cerebral circulation leading to periods of hypoxia is believed to play a significant role in the etiology of preterm brain injury, with the first three days of life considered the period when the brain is most vulnerable. This study focused on monitoring cerebral perfusion and metabolism during the first 72 h after birth in preterm infants weighing less than 1500 g. Brain monitoring was performed by combining hyperspectral near-infrared spectroscopy to assess oxygen saturation and the oxidation state of cytochrome c oxidase (oxCCO), with diffuse correlation spectroscopy to monitor cerebral blood flow (CBF). In seven of eight patients, oxCCO remained independent of CBF, indicating adequate oxygen delivery despite any fluctuations in cerebral hemodynamics. In the remaining infant, a significant correlation between CBF and oxCCO was found during the monitoring periods on days 1 and 3. This infant also had the lowest baseline CBF, suggesting the impact of CBF instabilities on metabolism depends on the level of blood supply to the brain. In summary, this study demonstrated for the first time how continuous perfusion and metabolic monitoring can be achieved, opening the possibility to investigate if CBF/oxCCO monitoring could help identify preterm infants at risk of brain injury.
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8
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Sidorenko I, Turova V, Rieger-Fackeldey E, Felderhoff-Müser U, Kovtanyuk A, Brodkorb S, Lampe R. Mathematical modeling of the hematocrit influence on cerebral blood flow in preterm infants. PLoS One 2021; 16:e0261819. [PMID: 34962951 PMCID: PMC8714087 DOI: 10.1371/journal.pone.0261819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 12/10/2021] [Indexed: 11/19/2022] Open
Abstract
Premature birth is one of the most important factors increasing the risk for brain damage in newborns. Development of an intraventricular hemorrhage in the immature brain is often triggered by fluctuations of cerebral blood flow (CBF). Therefore, monitoring of CBF becomes an important task in clinical care of preterm infants. Mathematical modeling of CBF can be a complementary tool in addition to diagnostic tools in clinical practice and research. The purpose of the present study is an enhancement of the previously developed mathematical model for CBF by a detailed description of apparent blood viscosity and vessel resistance, accounting for inhomogeneous hematocrit distribution in multiscale blood vessel architectures. The enhanced model is applied to our medical database retrospectively collected from the 254 preterm infants with a gestational age of 23-30 weeks. It is shown that by including clinically measured hematocrit in the mathematical model, apparent blood viscosity, vessel resistance, and hence the CBF are strongly affected. Thus, a statistically significant decrease in hematocrit values observed in the group of preterm infants with intraventricular hemorrhage resulted in a statistically significant increase in calculated CBF values.
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Affiliation(s)
- Irina Sidorenko
- Chair of Mathematical Modeling, Mathematical Faculty, Technical University of Munich, Garching, Germany
| | - Varvara Turova
- Research Unit for Pediatric Neuroorthopedics and Cerebral Palsy of the Buhl-Strohmaier Foundation, Orthopedic Department, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Esther Rieger-Fackeldey
- Department of Pediatrics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Ursula Felderhoff-Müser
- Neonatology, Pediatric Intensive Care, Pediatric Neurology, Department of Pediatrics I, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Andrey Kovtanyuk
- Research Unit for Pediatric Neuroorthopedics and Cerebral Palsy of the Buhl-Strohmaier Foundation, Orthopedic Department, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Silke Brodkorb
- Neonatology Department, Munich Clinic Harlaching, Munich, Germany
| | - Renée Lampe
- Research Unit for Pediatric Neuroorthopedics and Cerebral Palsy of the Buhl-Strohmaier Foundation, Orthopedic Department, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- * E-mail:
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9
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Ioussoufovitch S, Cohen DJF, Milej D, Diop M. Compressed sensing time-resolved spectrometer for quantification of light absorbers in turbid media. BIOMEDICAL OPTICS EXPRESS 2021; 12:6442-6460. [PMID: 34745748 PMCID: PMC8547999 DOI: 10.1364/boe.433427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/20/2021] [Accepted: 09/10/2021] [Indexed: 06/13/2023]
Abstract
Time-resolved (TR) spectroscopy is well-suited to address the challenges of quantifying light absorbers in highly scattering media such as living tissue; however, current TR spectrometers are either based on expensive array detectors or rely on wavelength scanning. Here, we introduce a TR spectrometer architecture based on compressed sensing (CS) and time-correlated single-photon counting. Using both CS and basis scanning, we demonstrate that-in homogeneous and two-layer tissue-mimicking phantoms made of Intralipid and Indocyanine Green-the CS method agrees with or outperforms uncompressed approaches. Further, we illustrate the superior depth sensitivity of TR spectroscopy and highlight the potential of the device to quantify absorption changes in deeper (>1 cm) tissue layers.
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Affiliation(s)
- Seva Ioussoufovitch
- Western University, Faculty of Engineering, School of Biomedical Engineering, Collaborative Training Program in Musculoskeletal Health Research, Bone & Joint Institute, 1151 Richmond St., London, N6A 5C1, Canada
| | - David Jonathan Fulop Cohen
- Western University, Schulich School of Medicine & Dentistry, Department of Medical Biophysics, 1151 Richmond St., London, N6A 5C1, Canada
| | - Daniel Milej
- Western University, Schulich School of Medicine & Dentistry, Department of Medical Biophysics, 1151 Richmond St., London, N6A 5C1, Canada
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor St., London, N6A 4V2, Canada
| | - Mamadou Diop
- Western University, Faculty of Engineering, School of Biomedical Engineering, Collaborative Training Program in Musculoskeletal Health Research, Bone & Joint Institute, 1151 Richmond St., London, N6A 5C1, Canada
- Western University, Schulich School of Medicine & Dentistry, Department of Medical Biophysics, 1151 Richmond St., London, N6A 5C1, Canada
- Lawson Health Research Institute, Imaging Program, 268 Grosvenor St., London, N6A 4V2, Canada
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10
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Cortese L, Lo Presti G, Pagliazzi M, Contini D, Dalla Mora A, Dehghani H, Ferri F, Fischer JB, Giovannella M, Martelli F, Weigel UM, Wojtkiewicz S, Zanoletti M, Durduran T. Recipes for diffuse correlation spectroscopy instrument design using commonly utilized hardware based on targets for signal-to-noise ratio and precision. BIOMEDICAL OPTICS EXPRESS 2021; 12:3265-3281. [PMID: 34221659 PMCID: PMC8221932 DOI: 10.1364/boe.423071] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/18/2021] [Accepted: 05/04/2021] [Indexed: 05/09/2023]
Abstract
Over the recent years, a typical implementation of diffuse correlation spectroscopy (DCS) instrumentation has been adapted widely. However, there are no detailed and accepted recipes for designing such instrumentation to meet pre-defined signal-to-noise ratio (SNR) and precision targets. These require specific attention due to the subtleties of the DCS signals. Here, DCS experiments have been performed using liquid tissue simulating phantoms to study the effect of the detected photon count-rate, the number of parallel detection channels and the measurement duration on the precision and SNR to suggest scaling relations to be utilized for device design.
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Affiliation(s)
- Lorenzo Cortese
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- These authors equally contributed to this work. Authors are listed in alphabetical order except for the first three and the last
| | - Giuseppe Lo Presti
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- These authors equally contributed to this work. Authors are listed in alphabetical order except for the first three and the last
| | - Marco Pagliazzi
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | | | - Hamid Dehghani
- University of Birmingham, School of Computer Science, Edgbaston, Birmingham, B15 2TT, UK
| | - Fabio Ferri
- Università degli Studi dell’Insubria, Dipartimento di Scienza e Alta Tecnologia and To. Sca. Lab., 22100 Como, Italy
| | - Jonas B. Fischer
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- HemoPhotonics S.L., 08860 Castelldefels (Barcelona), Spain
| | - Martina Giovannella
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Fabrizio Martelli
- Università degli Studi di Firenze, Dipartimento di Fisica, 50100 Firenze, Italy
| | - Udo M. Weigel
- HemoPhotonics S.L., 08860 Castelldefels (Barcelona), Spain
| | - Stanislaw Wojtkiewicz
- University of Birmingham, School of Computer Science, Edgbaston, Birmingham, B15 2TT, UK
| | - Marta Zanoletti
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Politecnico di Milano, Dipartimento di Fisica, 20133 Milano, Italy
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08015 Barcelona, Spain
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11
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Guerraty M, Bhargava A, Senarathna J, Mendelson AA, Pathak AP. Advances in translational imaging of the microcirculation. Microcirculation 2021; 28:e12683. [PMID: 33524206 PMCID: PMC8647298 DOI: 10.1111/micc.12683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/18/2021] [Accepted: 01/26/2021] [Indexed: 12/21/2022]
Abstract
The past few decades have seen an explosion in the development and use of methods for imaging the human microcirculation during health and disease. The confluence of innovative imaging technologies, affordable computing power, and economies of scale have ushered in a new era of "translational" imaging that permit us to peer into blood vessels of various organs in the human body. These imaging techniques include near-infrared spectroscopy (NIRS), positron emission tomography (PET), and magnetic resonance imaging (MRI) that are sensitive to microvascular-derived signals, as well as computed tomography (CT), optical imaging, and ultrasound (US) imaging that are capable of directly acquiring images at, or close to microvascular spatial resolution. Collectively, these imaging modalities enable us to characterize the morphological and functional changes in a tissue's microcirculation that are known to accompany the initiation and progression of numerous pathologies. Although there have been significant advances for imaging the microcirculation in preclinical models, this review focuses on developments in the assessment of the microcirculation in patients with optical imaging, NIRS, PET, US, MRI, and CT, to name a few. The goal of this review is to serve as a springboard for exploring the burgeoning role of translational imaging technologies for interrogating the structural and functional status of the microcirculation in humans, and highlight the breadth of current clinical applications. Making the human microcirculation "visible" in vivo to clinicians and researchers alike will facilitate bench-to-bedside discoveries and enhance the diagnosis and management of disease.
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Affiliation(s)
- Marie Guerraty
- Division of Cardiovascular Medicine, Department of
Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA,
USA
| | - Akanksha Bhargava
- Russell H. Morgan Department of Radiology and Radiological
Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Janaka Senarathna
- Russell H. Morgan Department of Radiology and Radiological
Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Asher A. Mendelson
- Department of Medicine, Section of Critical Care, Rady
Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Arvind P. Pathak
- Russell H. Morgan Department of Radiology and Radiological
Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Biomedical Engineering, The Johns Hopkins
University School of Medicine, Baltimore, MD, USA
- Department of Electrical Engineering, Johns Hopkins
University, Baltimore, MD, USA
- Sidney Kimmel Comprehensive Cancer Center, The Johns
Hopkins University School of Medicine, Baltimore, MD, USA
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12
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Huang C, Mazdeyasna S, Mohtasebi M, Saatman KE, Cheng Q, Yu G, Chen L. Speckle contrast diffuse correlation tomography of cerebral blood flow in perinatal disease model of neonatal piglets. JOURNAL OF BIOPHOTONICS 2021; 14:e202000366. [PMID: 33295142 PMCID: PMC8833087 DOI: 10.1002/jbio.202000366] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/05/2020] [Accepted: 12/06/2020] [Indexed: 05/11/2023]
Abstract
We adapted and tested an innovative noncontact speckle contrast diffuse correlation tomography (scDCT) system for 3D imaging of cerebral blood flow (CBF) variations in perinatal disease models utilizing neonatal piglets, which closely resemble human neonates. CBF variations were concurrently measured by the scDCT and an established diffuse correlation spectroscopy (DCS) during global ischemia, intraventricular hemorrhage, and asphyxia; significant correlations were observed. Moreover, CBF variations associated reasonably with vital pathophysiological changes. In contrast to DCS measurements of mixed signals from local scalp, skull and brain, scDCT generates 3D images of CBF distributions at prescribed depths within the head, thus enabling specific determination of regional cerebral ischemia. With further optimization and validation in animals and human neonates, scDCT has the potential to be a noninvasive imaging tool for both basic neuroscience research in laboratories and clinical applications in neonatal intensive care units.
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Affiliation(s)
- Chong Huang
- Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky
| | - Siavash Mazdeyasna
- Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky
| | - Mehrana Mohtasebi
- Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky
| | - Kathryn E. Saatman
- Department of Physiology, Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
| | - Qiang Cheng
- Division of Biomedical Informatics, Department of Internal Medicine, University of Kentucky, Lexington, Kentucky
| | - Guoqiang Yu
- Department of Biomedical Engineering, University of Kentucky, Lexington, Kentucky
| | - Lei Chen
- Department of Physiology, Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky
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13
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Pinti P, Siddiqui MF, Levy AD, Jones EJH, Tachtsidis I. An analysis framework for the integration of broadband NIRS and EEG to assess neurovascular and neurometabolic coupling. Sci Rep 2021; 11:3977. [PMID: 33597576 PMCID: PMC7889942 DOI: 10.1038/s41598-021-83420-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 01/28/2021] [Indexed: 01/31/2023] Open
Abstract
With the rapid growth of optical-based neuroimaging to explore human brain functioning, our research group has been developing broadband Near Infrared Spectroscopy (bNIRS) instruments, a technological extension to functional Near Infrared Spectroscopy (fNIRS). bNIRS has the unique capacity of monitoring brain haemodynamics/oxygenation (measuring oxygenated and deoxygenated haemoglobin), and metabolism (measuring the changes in the redox state of cytochrome-c-oxidase). When combined with electroencephalography (EEG), bNIRS provides a unique neuromonitoring platform to explore neurovascular coupling mechanisms. In this paper, we present a novel pipeline for the integrated analysis of bNIRS and EEG signals, and demonstrate its use on multi-channel bNIRS data recorded with concurrent EEG on healthy adults during a visual stimulation task. We introduce the use of the Finite Impulse Response functions within the General Linear Model for bNIRS and show its feasibility to statistically localize the haemodynamic and metabolic activity in the occipital cortex. Moreover, our results suggest that the fusion of haemodynamic and metabolic measures unveils additional information on brain functioning over haemodynamic imaging alone. The cross-correlation-based analysis of interrelationships between electrical (EEG) and haemodynamic/metabolic (bNIRS) activity revealed that the bNIRS metabolic signal offers a unique marker of brain activity, being more closely coupled to the neuronal EEG response.
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Affiliation(s)
- P. Pinti
- grid.83440.3b0000000121901201Department of Medical Physics and Biomedical Engineering, University College London, London, UK ,grid.4464.20000 0001 2161 2573Centre for Brain and Cognitive Development, Birkbeck College, University of London, London, UK
| | - M. F. Siddiqui
- grid.4464.20000 0001 2161 2573Centre for Brain and Cognitive Development, Birkbeck College, University of London, London, UK
| | - A. D. Levy
- grid.83440.3b0000000121901201Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London, UK ,grid.83440.3b0000000121901201Headache and Facial Pain, Brain Repair and Rehabilitation, Institute of Neurology, University College London, London, UK
| | - E. J. H. Jones
- grid.4464.20000 0001 2161 2573Centre for Brain and Cognitive Development, Birkbeck College, University of London, London, UK
| | - Ilias Tachtsidis
- grid.83440.3b0000000121901201Department of Medical Physics and Biomedical Engineering, University College London, London, UK
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14
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Kovacsova Z, Bale G, Mitra S, Lange F, Tachtsidis I. Absolute quantification of cerebral tissue oxygen saturation with multidistance broadband NIRS in newborn brain. BIOMEDICAL OPTICS EXPRESS 2021; 12:907-925. [PMID: 33680549 PMCID: PMC7901317 DOI: 10.1364/boe.412088] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/27/2020] [Accepted: 11/27/2020] [Indexed: 05/23/2023]
Abstract
Tissue oximetry with near-infrared spectroscopy (NIRS) is a technique for the measurement of absolute tissue oxygen saturation (StO2). Offering a real-time and non-invasive assessment of brain oxygenation and haemodynamics, StO2 has potential to be used for the assessment of newborn brain injury. Multiple algorithms have been developed to measure StO2, however, issues with low measurement accuracy or extracranial tissue signal contamination remain. In this work, we present a novel algorithm to recover StO2 in the neonate, broadband multidistance oximetry (BRUNO), based on a measurement of the gradient of attenuation against distance measured with broadband NIRS. The performance of the algorithm was compared to two other published algorithms, broadband fitting (BF) and spatially resolved spectroscopy (SRS). The median error when recovering StO2 in light transport simulations on a neonatal head mesh was 0.4% with BRUNO, 4.2% with BF and 9.5% with SRS. BRUNO was more sensitive to brain tissue oxygenation changes, shown in layered head model simulations. Comparison of algorithm performance during full oxygenation-deoxygenation cycles in a homogeneous dynamic blood phantom showed significant differences in the dynamic range of the algorithms; BRUNO recovered StO2 over 0-100%, BF over 0-90% and SRS over 39-80%. Recovering StO2 from data collected in a neonate treated at the neonatal intensive care showed different baseline values; mean StO2 was 64.9% with BRUNO, 67.2% with BF and 73.2% with SRS. These findings highlight the effect of StO2 algorithm selection on oxygenation recovery; applying BRUNO in the clinical care setting could reveal further insight into complex haemodynamic processes occurring during neonatal brain injury.
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Affiliation(s)
- Zuzana Kovacsova
- Department of Medical Physics & Biomedical Engineering, University College London, London, WC1E 6BT, UK
| | - Gemma Bale
- Department of Medical Physics & Biomedical Engineering, University College London, London, WC1E 6BT, UK
- Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK
- Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Subhabrata Mitra
- Institute for Women’s Health, University College London and Neonatal Unit, University College London Hospitals Trust, London, NW1 2BU, UK
| | - Frédéric Lange
- Department of Medical Physics & Biomedical Engineering, University College London, London, WC1E 6BT, UK
| | - Ilias Tachtsidis
- Department of Medical Physics & Biomedical Engineering, University College London, London, WC1E 6BT, UK
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15
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Harvey-Jones K, Lange F, Tachtsidis I, Robertson NJ, Mitra S. Role of Optical Neuromonitoring in Neonatal Encephalopathy-Current State and Recent Advances. Front Pediatr 2021; 9:653676. [PMID: 33898363 PMCID: PMC8062863 DOI: 10.3389/fped.2021.653676] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/15/2021] [Indexed: 11/19/2022] Open
Abstract
Neonatal encephalopathy (NE) in term and near-term infants is a significant global health problem; the worldwide burden of disease remains high despite the introduction of therapeutic hypothermia. Assessment of injury severity and effective management in the neonatal intensive care unit (NICU) relies on multiple monitoring modalities from systemic to brain-specific. Current neuromonitoring tools provide information utilized for seizure management, injury stratification, and prognostication, whilst systemic monitoring ensures multi-organ dysfunction is recognized early and supported wherever needed. The neuromonitoring technologies currently used in NE however, have limitations in either their availability during the active treatment window or their reliability to prognosticate and stratify injury confidently in the early period following insult. There is therefore a real need for a neuromonitoring tool that provides cot side, early and continuous monitoring of brain health which can reliably stratify injury severity, monitor response to current and emerging treatments, and prognosticate outcome. The clinical use of near-infrared spectroscopy (NIRS) technology has increased in recent years. Research studies within this population have also increased, alongside the development of both instrumentation and signal processing techniques. Increasing use of commercially available cerebral oximeters in the NICU, and the introduction of advanced optical measurements using broadband NIRS (BNIRS), frequency domain NIRS (FDNIRS), and diffuse correlation spectroscopy (DCS) have widened the scope by allowing the direct monitoring of oxygen metabolism and cerebral blood flow, both key to understanding pathophysiological changes and predicting outcome in NE. This review discusses the role of optical neuromonitoring in NE and why this modality may provide the next significant piece of the puzzle toward understanding the real time state of the injured newborn brain.
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Affiliation(s)
- Kelly Harvey-Jones
- Neonatology, EGA Institute for Women's Health, University College London, London, United Kingdom
| | - Frederic Lange
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Ilias Tachtsidis
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Nicola J Robertson
- Neonatology, EGA Institute for Women's Health, University College London, London, United Kingdom.,Edinburgh Neuroscience & Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Subhabrata Mitra
- Neonatology, EGA Institute for Women's Health, University College London, London, United Kingdom
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16
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McManus R, Ioussoufovitch S, Froats E, St Lawrence K, Van Uum S, Diop M. Dynamic response of cerebral blood flow to insulin-induced hypoglycemia. Sci Rep 2020; 10:21300. [PMID: 33277531 PMCID: PMC7718270 DOI: 10.1038/s41598-020-77626-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 11/11/2020] [Indexed: 11/25/2022] Open
Abstract
The dynamics of cerebral blood flow (CBF) at the onset of hypoglycemia may play a key role in hypoglycemia unawareness; however, there is currently a paucity of techniques that can monitor adult CBF with high temporal resolution. Herein, we investigated the use of diffuse correlation spectroscopy (DCS) to monitor the dynamics of CBF during insulin-induced hypoglycemia in adults. Plasma glucose concentrations, cortisol levels, and changes in CBF were measured before and during hypoglycemia in 8 healthy subjects. Cerebral blood flow increased by 42% following insulin injection with a delay of 17 ± 10 min, while the onset of hypoglycemia symptoms was delayed by 24 ± 11 min. The findings suggest that the onset of CBF increments precedes the appearance of hypoglycemia symptoms in nondiabetic subjects with normal awareness to hypoglycemia, and DCS could be a valuable tool for investigating the role of CBF in hypoglycemia unawareness.
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Affiliation(s)
- Ruth McManus
- St. Joseph's Health Care, London, ON, N6A 4V2, Canada
| | - Seva Ioussoufovitch
- Department of Biomedical Engineering, Western University, London, ON, N6A 5C1, Canada
| | | | - Keith St Lawrence
- St. Joseph's Health Care, London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, ON, N6A 5C1, Canada
| | - Stan Van Uum
- St. Joseph's Health Care, London, ON, N6A 4V2, Canada
| | - Mamadou Diop
- St. Joseph's Health Care, London, ON, N6A 4V2, Canada.
- Department of Biomedical Engineering, Western University, London, ON, N6A 5C1, Canada.
- Department of Medical Biophysics, Western University, London, ON, N6A 5C1, Canada.
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17
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Busch DR, Baker WB, Mavroudis CD, Ko TS, Lynch JM, McCarthy AL, DuPont-Thibodeau G, Buckley EM, Jacobwitz M, Boorady TW, Mensah-Brown K, Connelly JT, Yodh AG, Kilbaugh TJ, Licht DJ. Noninvasive optical measurement of microvascular cerebral hemodynamics and autoregulation in the neonatal ECMO patient. Pediatr Res 2020; 88:925-933. [PMID: 32172282 PMCID: PMC7492409 DOI: 10.1038/s41390-020-0841-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 02/12/2020] [Accepted: 02/19/2020] [Indexed: 01/14/2023]
Abstract
BACKGROUND Extra-corporeal membrane oxygenation (ECMO) is a life-saving intervention for severe respiratory and cardiac diseases. However, 50% of survivors have abnormal neurologic exams. Current ECMO management is guided by systemic metrics, which may poorly predict cerebral perfusion. Continuous optical monitoring of cerebral hemodynamics during ECMO holds potential to detect risk factors of brain injury such as impaired cerebrovascular autoregulation (CA). METHODS We conducted daily measurements of microvascular cerebral blood flow (CBF), oxygen saturation, and total hemoglobin concentration using diffuse correlation spectroscopy (DCS) and frequency-domain diffuse optical spectroscopy in nine neonates. We characterize CA utilizing the correlation coefficient (DCSx) between CBF and mean arterial blood pressure (MAP) during ECMO pump flow changes. RESULTS Average MAP and pump flow levels were weakly correlated with CBF and were not correlated with cerebral oxygen saturation. CA integrity varied between individuals and with time. Systemic measurements of MAP, pulse pressure, and left cardiac dysfunction were not predictive of impaired CA. CONCLUSIONS Our pilot results suggest that systemic measures alone cannot distinguish impaired CA from intact CA during ECMO. Furthermore, optical neuromonitoring could help determine patient-specific ECMO pump flows for optimal CA integrity, thereby reducing risk of secondary brain injury. IMPACT Cerebral blood flow and oxygenation are not well predicted by systemic proxies such as ECMO pump flow or blood pressure. Continuous, quantitative, bedside monitoring of cerebral blood flow and oxygenation with optical tools enables new insight into the adequacy of cerebral perfusion during ECMO. A demonstration of hybrid diffuse optical and correlation spectroscopies to continuously measure cerebral blood oxygen saturation and flow in patients on ECMO, enabling assessment of cerebral autoregulation. An observation of poor correlation of cerebral blood flow and oxygenation with systemic mean arterial pressure and ECMO pump flow, suggesting that clinical decision making guided by target values for these surrogates may not be neuroprotective. ~50% of ECMO survivors have long-term neurological deficiencies; continuous monitoring of brain health throughout therapy may reduce these tragically common sequelae through brain-focused adjustment of ECMO parameters.
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Affiliation(s)
- David R Busch
- Departments of Anesthesiology & Pain Management and Neurology & Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Wesley B Baker
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Constantine D Mavroudis
- Division of Cardiovascular Surgery, Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Tiffany S Ko
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Jennifer M Lynch
- Department of Anesthesiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Ann L McCarthy
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | - Erin M Buckley
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA, USA
| | - Marin Jacobwitz
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Timothy W Boorady
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kobina Mensah-Brown
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - James T Connelly
- ECMO Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Arjun G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Todd J Kilbaugh
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Daniel J Licht
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
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18
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Rajaram A, Milej D, Suwalski M, Yip LCM, Guo LR, Chu MWA, Chui J, Diop M, Murkin JM, St. Lawrence K. Optical monitoring of cerebral perfusion and metabolism in adults during cardiac surgery with cardiopulmonary bypass. BIOMEDICAL OPTICS EXPRESS 2020; 11:5967-5981. [PMID: 33149999 PMCID: PMC7587277 DOI: 10.1364/boe.404101] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/03/2020] [Accepted: 09/03/2020] [Indexed: 05/23/2023]
Abstract
During cardiac surgery with cardiopulmonary bypass (CPB), adequate maintenance of cerebral blood flow (CBF) is vital in preventing postoperative neurological injury - i.e. stroke, delirium, cognitive impairment. Reductions in CBF large enough to impact cerebral energy metabolism can lead to tissue damage and subsequent brain injury. Current methods for neuromonitoring during surgery are limited. This study presents the clinical translation of a hybrid optical neuromonitor for continuous intraoperative monitoring of cerebral perfusion and metabolism in ten patients undergoing non-emergent cardiac surgery with non-pulsatile CPB. The optical system combines broadband near-infrared spectroscopy (B-NIRS) to measure changes in the oxidation state of cytochrome c oxidase (oxCCO) - a direct marker of cellular energy metabolism - and diffuse correlation spectroscopy (DCS) to provide an index of cerebral blood flow (CBFi). As the heart was arrested and the CPB-pump started, increases in CBFi (88.5 ± 125.7%) and significant decreases in oxCCO (-0.5 ± 0.2 µM) were observed; no changes were noted during transitions off CPB. Fifteen hypoperfusion events, defined as large and sustained reductions in CPB-pump flow rate, were identified across all patients and resulted in significant decreases in perfusion and metabolism when mean arterial pressure dropped to 30 mmHg or below. The maximum reduction in cerebral blood flow preceded the corresponding metabolic reduction by 18.2 ± 15.0 s. Optical neuromonitoring provides a safe and non-invasive approach for assessing intraoperative perfusion and metabolism and has potential in guiding patient management to prevent adverse clinical outcomes.
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Affiliation(s)
- Ajay Rajaram
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Daniel Milej
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
| | - Marianne Suwalski
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Lawrence C. M. Yip
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Linrui R. Guo
- Division of Cardiac Surgery, London Health Science Centre, 339 Windermere Rd, London, ON, N6A 5A5, Canada
| | - Michael W. A. Chu
- Division of Cardiac Surgery, London Health Science Centre, 339 Windermere Rd, London, ON, N6A 5A5, Canada
| | - Jason Chui
- Department of Anesthesiology and Perioperative Medicine, London Health Science Centre, 339 Windermere Rd, London, ON, N6A 5A5, Canada
| | - Mamadou Diop
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - John M. Murkin
- Department of Anesthesiology and Perioperative Medicine, London Health Science Centre, 339 Windermere Rd, London, ON, N6A 5A5, Canada
| | - Keith St. Lawrence
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
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19
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Milej D, Abdalmalak A, Rajaram A, St. Lawrence K. Direct assessment of extracerebral signal contamination on optical measurements of cerebral blood flow, oxygenation, and metabolism. NEUROPHOTONICS 2020; 7:045002. [PMID: 33062801 PMCID: PMC7540337 DOI: 10.1117/1.nph.7.4.045002] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 09/04/2020] [Indexed: 05/08/2023]
Abstract
Significance: Near-infrared spectroscopy (NIRS) combined with diffuse correlation spectroscopy (DCS) provides a noninvasive approach for monitoring cerebral blood flow (CBF), oxygenation, and oxygen metabolism. However, these methods are vulnerable to signal contamination from the scalp. Our work evaluated methods of reducing the impact of this contamination using time-resolved (TR) NIRS and multidistance (MD) DCS. Aim: The magnitude of scalp contamination was evaluated by measuring the flow, oxygenation, and metabolic responses to a global hemodynamic challenge. Contamination was assessed by collecting data with and without impeding scalp blood flow. Approach: Experiments involved healthy participants. A pneumatic tourniquet was used to cause scalp ischemia, as confirmed by contrast-enhanced NIRS, and a computerized gas system to generate a hypercapnic challenge. Results: Comparing responses acquired with and without the tourniquet demonstrated that the TR-NIRS technique could reduce scalp contributions in hemodynamic signals up to 4 times (r SD = 3 cm ) and 6 times (r SD = 4 cm ). Similarly, blood flow responses from the scalp and brain could be separated by analyzing MD DCS data with a multilayer model. Using these techniques, there was no change in metabolism during hypercapnia, as expected, despite large increases in CBF and oxygenation. Conclusion: NIRS/DCS can accurately monitor CBF and metabolism with the appropriate enhancement to depth sensitivity, highlighting the potential of these techniques for neuromonitoring.
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Affiliation(s)
- Daniel Milej
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
| | - Androu Abdalmalak
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
| | - Ajay Rajaram
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
| | - Keith St. Lawrence
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Department of Medical Biophysics, London, Ontario, Canada
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20
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Milej D, He L, Abdalmalak A, Baker WB, Anazodo UC, Diop M, Dolui S, Kavuri VC, Pavlosky W, Wang L, Balu R, Detre JA, Amendolia O, Quattrone F, Kofke WA, Yodh AG, St Lawrence K. Quantification of cerebral blood flow in adults by contrast-enhanced near-infrared spectroscopy: Validation against MRI. J Cereb Blood Flow Metab 2020; 40:1672-1684. [PMID: 31500522 PMCID: PMC7370369 DOI: 10.1177/0271678x19872564] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 07/29/2019] [Indexed: 12/11/2022]
Abstract
The purpose of this study was to assess the accuracy of absolute cerebral blood flow (CBF) measurements obtained by dynamic contrast-enhanced (DCE) near-infrared spectroscopy (NIRS) using indocyanine green as a perfusion contrast agent. For validation, CBF was measured independently using the MRI perfusion method arterial spin labeling (ASL). Data were acquired at two sites and under two flow conditions (normocapnia and hypercapnia). Depth sensitivity was enhanced using time-resolved detection, which was demonstrated in a separate set of experiments using a tourniquet to temporally impede scalp blood flow. A strong correlation between CBF measurements from ASL and DCE-NIRS was observed (slope = 0.99 ± 0.08, y-intercept = -1.7 ± 7.4 mL/100 g/min, and R2 = 0.88). Mean difference between the two techniques was 1.9 mL/100 g/min (95% confidence interval ranged from -15 to 19 mL/100g/min and the mean ASL CBF was 75.4 mL/100 g/min). Error analysis showed that structural information and baseline absorption coefficient were needed for optimal CBF reconstruction with DCE-NIRS. This study demonstrated that DCE-NIRS is sensitive to blood flow in the adult brain and can provide accurate CBF measurements with the appropriate modeling techniques.
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Affiliation(s)
- Daniel Milej
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Lian He
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Androu Abdalmalak
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Wesley B Baker
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
| | - Udunna C Anazodo
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Mamadou Diop
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Sudipto Dolui
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Venkaiah C Kavuri
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - William Pavlosky
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Lin Wang
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Ramani Balu
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - John A Detre
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Olivia Amendolia
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Francis Quattrone
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - W Andrew Kofke
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Arjun G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Keith St Lawrence
- Department of Medical Biophysics, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
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21
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Rajaram A, Yip LCM, Milej D, Suwalski M, Kewin M, Lo M, Carson JJL, Han V, Bhattacharya S, Diop M, de Ribaupierre S, St. Lawrence K. Perfusion and Metabolic Neuromonitoring during Ventricular Taps in Infants with Post-Hemorrhagic Ventricular Dilatation. Brain Sci 2020; 10:E452. [PMID: 32679665 PMCID: PMC7407524 DOI: 10.3390/brainsci10070452] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/03/2020] [Accepted: 07/13/2020] [Indexed: 01/08/2023] Open
Abstract
Post-hemorrhagic ventricular dilatation (PHVD) is characterized by a build-up of cerebral spinal fluid (CSF) in the ventricles, which increases intracranial pressure and compresses brain tissue. Clinical interventions (i.e., ventricular taps, VT) work to mitigate these complications through CSF drainage; however, the timing of these procedures remains imprecise. This study presents Neonatal NeuroMonitor (NNeMo), a portable optical device that combines broadband near-infrared spectroscopy (B-NIRS) and diffuse correlation spectroscopy (DCS) to provide simultaneous assessments of cerebral blood flow (CBF), tissue saturation (StO2), and the oxidation state of cytochrome c oxidase (oxCCO). In this study, NNeMo was used to monitor cerebral hemodynamics and metabolism in PHVD patients selected for a VT. Across multiple VTs in four patients, no significant changes were found in any of the three parameters: CBF increased by 14.6 ± 37.6% (p = 0.09), StO2 by 1.9 ± 4.9% (p = 0.2), and oxCCO by 0.4 ± 0.6 µM (p = 0.09). However, removing outliers resulted in significant, but small, increases in CBF (6.0 ± 7.7%) and oxCCO (0.1 ± 0.1 µM). The results of this study demonstrate NNeMo's ability to provide safe, non-invasive measurements of cerebral perfusion and metabolism for neuromonitoring applications in the neonatal intensive care unit.
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Affiliation(s)
- Ajay Rajaram
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada; (L.C.M.Y.); (D.M.); (M.S.); (M.K.); (M.L.); (J.J.L.C.); (M.D.); (K.S.L.)
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 3K7, Canada;
| | - Lawrence C. M. Yip
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada; (L.C.M.Y.); (D.M.); (M.S.); (M.K.); (M.L.); (J.J.L.C.); (M.D.); (K.S.L.)
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 3K7, Canada;
| | - Daniel Milej
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada; (L.C.M.Y.); (D.M.); (M.S.); (M.K.); (M.L.); (J.J.L.C.); (M.D.); (K.S.L.)
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 3K7, Canada;
| | - Marianne Suwalski
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada; (L.C.M.Y.); (D.M.); (M.S.); (M.K.); (M.L.); (J.J.L.C.); (M.D.); (K.S.L.)
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 3K7, Canada;
| | - Matthew Kewin
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada; (L.C.M.Y.); (D.M.); (M.S.); (M.K.); (M.L.); (J.J.L.C.); (M.D.); (K.S.L.)
| | - Marcus Lo
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada; (L.C.M.Y.); (D.M.); (M.S.); (M.K.); (M.L.); (J.J.L.C.); (M.D.); (K.S.L.)
| | - Jeffrey J. L. Carson
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada; (L.C.M.Y.); (D.M.); (M.S.); (M.K.); (M.L.); (J.J.L.C.); (M.D.); (K.S.L.)
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 3K7, Canada;
| | - Victor Han
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, London Health Sciences Centre, London, ON N6A 3K7, Canada; (V.H.); (S.B.)
| | - Soume Bhattacharya
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, London Health Sciences Centre, London, ON N6A 3K7, Canada; (V.H.); (S.B.)
| | - Mamadou Diop
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada; (L.C.M.Y.); (D.M.); (M.S.); (M.K.); (M.L.); (J.J.L.C.); (M.D.); (K.S.L.)
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 3K7, Canada;
| | - Sandrine de Ribaupierre
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 3K7, Canada;
- Department of Clinical Neurological Sciences, London Health Sciences Centre, London, ON N6A 5W9, Canada
| | - Keith St. Lawrence
- Imaging Program, Lawson Health Research Institute, London, ON N6A 4V2, Canada; (L.C.M.Y.); (D.M.); (M.S.); (M.K.); (M.L.); (J.J.L.C.); (M.D.); (K.S.L.)
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON N6A 3K7, Canada;
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22
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Ioussoufovitch S, Morrison LB, Desjardins L, Hadway JA, Lawrence KS, Lee TY, Beier F, Diop M. Quantification of joint blood flow by dynamic contrast-enhanced near-infrared spectroscopy: application to monitoring disease activity in a rat model of rheumatoid arthritis. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-10. [PMID: 31939225 PMCID: PMC6983648 DOI: 10.1117/1.jbo.25.1.015003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 12/06/2019] [Indexed: 05/11/2023]
Abstract
Significance Current guidelines for rheumatoid arthritis (RA) management recommend early treatment with disease modifying antirheumatic drugs (DMARDs). However, DMARD treatment fails in 30% of patients and current monitoring methods can only detect failure after 3 to 6 months of therapy. Aim We investigated whether joint blood flow (BF), quantified using dynamic contrast-enhanced time-resolved near-infrared spectroscopy, can monitor disease activity and treatment response in a rat model of RA. Approach Ankle joint BF was measured every 5 days in eight rats with adjuvant-induced arthritis (AIA) and four healthy controls. Arthritis was allowed to progress for 20 days before rats with AIA were treated with a DMARD once every 5 days until day 40. Results Time and group had separate significant main effects on joint BF; however, there was no significant interaction between time and group despite a notable difference in average joint BF on day 5. Comparison of individual blood flow measures between rats with AIA and control group animals did not reveal a clear response to treatment. Conclusions Joint BF time courses could not distinguish between rats with AIA and study controls. Heterogeneous disease response and low temporal frequency of BF measurements may have been important study limitations.
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Affiliation(s)
- Seva Ioussoufovitch
- Western University, Bone and Joint Institute, School of Biomedical Engineering, Faculty of Engineering, London, Ontario, Canada
| | - Laura B. Morrison
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - Lise Desjardins
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - Jennifer A. Hadway
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
| | - Keith St. Lawrence
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Schulich School of Medicine and Dentistry, Department of Medical Biophysics, London, Ontario, Canada
| | - Ting-Yim Lee
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Schulich School of Medicine and Dentistry, Department of Medical Biophysics, London, Ontario, Canada
- Robarts Research Institute, Imaging Program, London, Ontario, Canada
| | - Frank Beier
- Western University, Schulich School of Medicine and Dentistry, Department of Physiology and Pharmacology, London, Ontario, Canada
| | - Mamadou Diop
- Western University, Bone and Joint Institute, School of Biomedical Engineering, Faculty of Engineering, London, Ontario, Canada
- Lawson Health Research Institute, Imaging Program, London, Ontario, Canada
- Western University, Schulich School of Medicine and Dentistry, Department of Medical Biophysics, London, Ontario, Canada
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23
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Kewin M, Rajaram A, Milej D, Abdalmalak A, Morrison L, Diop M, St Lawrence K. Evaluation of hyperspectral NIRS for quantitative measurements of tissue oxygen saturation by comparison to time-resolved NIRS. BIOMEDICAL OPTICS EXPRESS 2019; 10:4789-4802. [PMID: 31565525 PMCID: PMC6757477 DOI: 10.1364/boe.10.004789] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/14/2019] [Accepted: 08/14/2019] [Indexed: 05/17/2023]
Abstract
Near-infrared spectroscopy (NIRS) is considered ideal for brain monitoring during preterm infancy because it is non-invasive and provides a continuous measure of tissue oxygen saturation (StO2). Hyperspectral NIRS (HS NIRS) is an inexpensive, quantitative modality that can measure tissue optical properties and oxygen saturation (StO2) by differential spectroscopy. In this study, experiments were conducted using newborn piglets to measure StO2 across a range of oxygenation levels from hyperoxia to hypoxia by HS and time-resolved (TR) NIRS for validation. A strong correlation between StO2 measurements from the two techniques was observed (R2 = 0.98, average slope of 1.02 ± 0.28); however, the HS-NIRS estimates were significantly higher than the corresponding TR-NIRS values. These regression results indicate that HS NIRS could become a clinically feasible method for monitoring StO2 in preterm infants.
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Affiliation(s)
- Matthew Kewin
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Ajay Rajaram
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Daniel Milej
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Androu Abdalmalak
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Laura Morrison
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
| | - Mamadou Diop
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Keith St Lawrence
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
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24
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Khalid M, Milej D, Rajaram A, Abdalmalak A, Morrison L, Diop M, St. Lawrence K. Development of a stand-alone DCS system for monitoring absolute cerebral blood flow. BIOMEDICAL OPTICS EXPRESS 2019; 10:4607-4620. [PMID: 31565512 PMCID: PMC6757462 DOI: 10.1364/boe.10.004607] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 05/23/2023]
Abstract
Diffuse correlation spectroscopy (DCS) is a noninvasive optical technique for monitoring cerebral blood flow (CBF). This work presents a stand-alone DCS system capable of monitoring absolute CBF by incorporating a quantitative dynamic contrast-enhanced (DCE) technique. Multi-distance data were acquired to measure the tissue optical properties and to perform DCE experiments. Feasibility of the technique was assessed in piglets in which the optical properties were measured independently by time-resolved near-infrared spectroscopy. A strong linear correlation was observed between CBF values derived using the two sets of optical properties, demonstrating that this hybrid DCS approach can provide real-time monitoring of absolute CBF.
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Affiliation(s)
- Mahro Khalid
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Daniel Milej
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Ajay Rajaram
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Androu Abdalmalak
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Laura Morrison
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
| | - Mamadou Diop
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
| | - Keith St. Lawrence
- Imaging Program, Lawson Health Research Institute, London, Ontario, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, London, Ontario, N6A 5C1, Canada
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25
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Baker WB, Balu R, He L, Kavuri VC, Busch DR, Amendolia O, Quattrone F, Frangos S, Maloney-Wilensky E, Abramson K, Mahanna Gabrielli E, Yodh AG, Andrew Kofke W. Continuous non-invasive optical monitoring of cerebral blood flow and oxidative metabolism after acute brain injury. J Cereb Blood Flow Metab 2019; 39:1469-1485. [PMID: 31088234 PMCID: PMC6681541 DOI: 10.1177/0271678x19846657] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Rapid detection of ischemic conditions at the bedside can improve treatment of acute brain injury. In this observational study of 11 critically ill brain-injured adults, we employed a monitoring approach that interleaves time-resolved near-infrared spectroscopy (TR-NIRS) measurements of cerebral oxygen saturation and oxygen extraction fraction (OEF) with diffuse correlation spectroscopy (DCS) measurement of cerebral blood flow (CBF). Using this approach, we demonstrate the clinical promise of non-invasive, continuous optical monitoring of changes in CBF and cerebral metabolic rate of oxygen (CMRO2). In addition, the optical CBF and CMRO2 measures were compared to invasive brain tissue oxygen tension (PbtO2), thermal diffusion flowmetry CBF, and cerebral microdialysis measures obtained concurrently. The optical CBF and CMRO2 information successfully distinguished between ischemic, hypermetabolic, and hyperemic conditions that arose spontaneously during patient care. Moreover, CBF monitoring during pressor-induced changes of mean arterial blood pressure enabled assessment of cerebral autoregulation. In total, the findings suggest that this hybrid non-invasive neurometabolic optical monitor (NNOM) can facilitate clinical detection of adverse physiological changes in brain injured patients that are otherwise difficult to measure with conventional bedside monitoring techniques.
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Affiliation(s)
- Wesley B Baker
- 1 Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA.,2 Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Ramani Balu
- 3 Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Lian He
- 4 Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Venkaiah C Kavuri
- 4 Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - David R Busch
- 4 Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA.,5 Department of Anesthesiology & Pain Management and Neurology & Neurotherapeutics, University of Texas Southwestern, Dallas, TX, USA
| | - Olivia Amendolia
- 6 Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Francis Quattrone
- 6 Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Suzanne Frangos
- 6 Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Kenneth Abramson
- 4 Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Arjun G Yodh
- 4 Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - W Andrew Kofke
- 1 Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, USA
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26
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Sidorenko I, Turova V, Botkin N, Eckardt L, Alves-Pinto A, Felderhoff-Müser U, Rieger-Fackeldey E, Kovtanyuk A, Lampe R. Modeling Cerebral Blood Flow Dependence on Carbon Dioxide and Mean Arterial Blood Pressure in the Immature Brain With Accounting for the Germinal Matrix. Front Neurol 2018; 9:812. [PMID: 30356709 PMCID: PMC6189337 DOI: 10.3389/fneur.2018.00812] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 09/10/2018] [Indexed: 12/20/2022] Open
Abstract
Intraventricular hemorrhage (IVH) is one of the most critical complications in the development of preterm infants. The likelihood of IVH is strongly associated with disturbances in cerebral blood flow (CBF) and with microvascular fragility in the germinal matrix (GM). The CBF value and its reactivity to changes in arterial carbon dioxide pressure (pCO2) and mean arterial blood pressure (MABP) are relevant indicators in the clinical assessment of preterm infants. The objective of the present study is mathematical modeling of the influence of pCO2 and MABP on CBF in immature brain, based on clinical data collected from 265 preterm infants with 23–30 gestational weeks. The model was adapted to the peculiarities of immature brain by taking into account the morphological characteristics of the GM capillary network and vascular reactivity, according to gestational and postnatal age. An analysis of model based values of CBF and its reactivity to changes in MABP and pCO2 was performed separately for each gestational week and for the first two days of life both for preterm infants with and without IVH. The developed model for the estimation of CBF was validated against equivalent experimental measurements taken from the literature. A good agreement between the estimated values of CBF, as well as its reaction on changes in MABP and pCO2 and the equivalent values obtained in experimental studies was shown.
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Affiliation(s)
- Irina Sidorenko
- Mathematical Faculty, Technical University of Munich, Garching, Germany
| | - Varvara Turova
- Orthopedic Department, University Hospital Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Nikolai Botkin
- Mathematical Faculty, Technical University of Munich, Garching, Germany
| | - Laura Eckardt
- Pediatric Department I, Neonatology, Pediatric Intensive Care, Pediatric Neurology, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Ana Alves-Pinto
- Orthopedic Department, University Hospital Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Ursula Felderhoff-Müser
- Pediatric Department I, Neonatology, Pediatric Intensive Care, Pediatric Neurology, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Esther Rieger-Fackeldey
- Pediatric Department, University Hospital Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Andrey Kovtanyuk
- Orthopedic Department, University Hospital Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Renée Lampe
- Orthopedic Department, University Hospital Rechts der Isar, Technical University of Munich, Munich, Germany
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27
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He L, Baker WB, Milej D, Kavuri VC, Mesquita RC, Busch DR, Abramson K, Jiang JY, Diop M, St. Lawrence K, Amendolia O, Quattrone F, Balu R, Kofke WA, Yodh AG. Noninvasive continuous optical monitoring of absolute cerebral blood flow in critically ill adults. NEUROPHOTONICS 2018; 5:045006. [PMID: 30480039 PMCID: PMC6251207 DOI: 10.1117/1.nph.5.4.045006] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Accepted: 10/29/2018] [Indexed: 05/18/2023]
Abstract
We investigate a scheme for noninvasive continuous monitoring of absolute cerebral blood flow (CBF) in adult human patients based on a combination of time-resolved dynamic contrast-enhanced near-infrared spectroscopy (DCE-NIRS) and diffuse correlation spectroscopy (DCS) with semi-infinite head model of photon propogation. Continuous CBF is obtained via calibration of the DCS blood flow index (BFI) with absolute CBF obtained by intermittent intravenous injections of the optical contrast agent indocyanine green. A calibration coefficient ( γ ) for the CBF is thus determined, permitting conversion of DCS BFI to absolute blood flow units at all other times. A study of patients with acute brain injury ( N = 7 ) is carried out to ascertain the stability of γ . The patient-averaged DCS calibration coefficient across multiple monitoring days and multiple patients was determined, and good agreement between the two calibration coefficients measured at different times during single monitoring days was found. The patient-averaged calibration coefficient of 1.24 × 10 9 ( mL / 100 g / min ) / ( cm 2 / s ) was applied to previously measured DCS BFI from similar brain-injured patients; in this case, absolute CBF was underestimated compared with XeCT, an effect we show is primarily due to use of semi-infinite homogeneous models of the head.
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Affiliation(s)
- Lian He
- University of Pennsylvania, Department of Physics and Astronomy, Philadelphia, Pennsylvania, United States
- Address all correspondence to: Lian He, E-mail:
| | - Wesley B. Baker
- University of Pennsylvania, Department of Physics and Astronomy, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, Department of Anesthesiology and Critical Care, Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Daniel Milej
- Western University, Department of Medical Biophysics, London, Ontario, Canada
- Lawson Health Research Institute, Imaging Division, London, Ontario, Canada
| | - Venkaiah C. Kavuri
- University of Pennsylvania, Department of Physics and Astronomy, Philadelphia, Pennsylvania, United States
| | | | - David R. Busch
- University of Texas Southwestern, Department of Neurology and Neurotherapeutics, Dallas, Texas, United States
- University of Texas Southwestern, Department of Anesthesiology and Pain Management, Dallas, Texas, United States
| | - Kenneth Abramson
- University of Pennsylvania, Department of Physics and Astronomy, Philadelphia, Pennsylvania, United States
| | - Jane Y. Jiang
- University of Pennsylvania, Department of Physics and Astronomy, Philadelphia, Pennsylvania, United States
| | - Mamadou Diop
- Western University, Department of Medical Biophysics, London, Ontario, Canada
- Lawson Health Research Institute, Imaging Division, London, Ontario, Canada
| | - Keith St. Lawrence
- Western University, Department of Medical Biophysics, London, Ontario, Canada
- Lawson Health Research Institute, Imaging Division, London, Ontario, Canada
| | - Olivia Amendolia
- University of Pennsylvania, Department of Neurosurgery, Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Francis Quattrone
- University of Pennsylvania, Department of Neurosurgery, Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Ramani Balu
- University of Pennsylvania, Department of Neurosurgery, Perelman School of Medicine, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, Department of Neurology, Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - W. Andrew Kofke
- University of Pennsylvania, Department of Anesthesiology and Critical Care, Perelman School of Medicine, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, Department of Neurosurgery, Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Arjun G. Yodh
- University of Pennsylvania, Department of Physics and Astronomy, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, Department of Anesthesiology and Critical Care, Perelman School of Medicine, Philadelphia, Pennsylvania, United States
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28
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Rajaram A, Bale G, Kewin M, Morrison LB, Tachtsidis I, St. Lawrence K, Diop M. Simultaneous monitoring of cerebral perfusion and cytochrome c oxidase by combining broadband near-infrared spectroscopy and diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2018; 9:2588-2603. [PMID: 30258675 PMCID: PMC6154190 DOI: 10.1364/boe.9.002588] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 05/23/2023]
Abstract
Preterm infants born with very low birth weights are at a high risk of brain injury, in part because the premature brain is believed to be prone to periods of low cerebral blood flow (CBF). Tissue damage is likely to occur if reduction in CBF is sufficient to impair cerebral energy metabolism for extended periods. Therefore, a neuromonitoring method that can detect reductions in CBF, large enough to affect metabolism, could alert the neonatal intensive care team before injury occurs. In this report, we present the development of an optical system that combines diffuse correlation spectroscopy (DCS) for monitoring CBF and broadband near-infrared spectroscopy (B-NIRS) for monitoring the oxidation state of cytochrome c oxidase (oxCCO) - a key biomarker of oxidative metabolism. The hybrid instrument includes a multiplexing system to enable concomitant DCS and B-NIRS measurements while avoiding crosstalk between the two subsystems. The ability of the instrument to monitor dynamic changes in CBF and oxCCO was demonstrated in a piglet model of neonatal hypoxia-ischemia (HI). Experiments conducted in eight animals, including two controls, showed that oxCCO exhibited a delayed response to ischemia while CBF and tissue oxygenation (StO2) responses were instantaneous. These findings suggest that simultaneous neuromonitoring of perfusion and metabolism could provide critical information regarding clinically significant hemodynamic events prior to the onset of brain injury.
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Affiliation(s)
- Ajay Rajaram
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Gemma Bale
- Medical Physics & Biomedical Engineering, University College London, Gower St., Bloomsbury, London, WC1E 6BT, United Kingdom
| | - Matthew Kewin
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Laura B. Morrison
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
| | - Ilias Tachtsidis
- Medical Physics & Biomedical Engineering, University College London, Gower St., Bloomsbury, London, WC1E 6BT, United Kingdom
| | - Keith St. Lawrence
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Mamadou Diop
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
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29
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Broadband NIRS Cerebral Cytochrome-C-Oxidase Response to Anoxia Before and After Hypoxic-Ischaemic Injury in Piglets. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1072:151-156. [PMID: 30178338 PMCID: PMC6142853 DOI: 10.1007/978-3-319-91287-5_24] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Perinatal hypoxic ischaemic (HI) encephalopathy is associated with severe neurodevelopment problems and mortality. This study uses broadband continuous-wave near-infrared spectroscopy (NIRS) to assess the early changes in cerebral oxygenation and metabolism after HI injury in an animal model using controlled anoxia events. Anoxia was induced before and 1 h after various levels of HI injury to assess the metabolic response via the changes in the oxidation state of cytochrome-c-oxidase (oxCCO), a marker of oxidative metabolism. The oxCCO responses to anoxia were classified into five categories: increase, no change, decrease, biphasic and triphasic responses. The most common response (54%) was a biphasic decrease in oxCCO. A change in the classification of the metabolic response to anoxia after HI injury indicated a severe injury, as determined by proton magnetic resonance spectroscopy, with 86% sensitivity. This shows that broadband NIRS can identify disturbances to cerebral metabolism in the first hours after severe HI injury.
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McLachlan PJ, Kishimoto J, Diop M, Milej D, Lee DSC, de Ribaupierre S, St Lawrence K. Investigating the effects of cerebrospinal fluid removal on cerebral blood flow and oxidative metabolism in infants with post-hemorrhagic ventricular dilatation. Pediatr Res 2017; 82:634-641. [PMID: 28553990 DOI: 10.1038/pr.2017.131] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 04/28/2017] [Indexed: 11/09/2022]
Abstract
BackgroundPost-hemorrhagic ventricular dilatation (PHVD) is predictive of mortality and morbidity among very-low-birth-weight preterm infants. Impaired cerebral blood flow (CBF) due to elevated intracranial pressure (ICP) is believed to be a contributing factor.MethodsA hyperspectral near-infrared spectroscopy (NIRS) method of measuring CBF and the cerebral metabolic rate of oxygen (CMRO2) was used to investigate perfusion and metabolism changes in patients receiving a ventricular tap (VT) based on clinical management. To improve measurement accuracy, the spectral analysis was modified to account for compression of the cortical mantle caused by PHVD and the possible presence of blood breakdown products.ResultsFrom nine patients (27 VTs), a significant CBF increase was measured (15.6%) following VT (14.6±4.2 to 16.9±6.6 ml/100 g/min), but with no corresponding change in CMRO2 (1.02±0.41 ml O2/100 g/min). Post-VT CBF was in good agreement with a control group of 13 patients with patent ductus arteriosus but no major cerebral pathology (16.5±7.7 ml/100 g/min), whereas tissue oxygen saturation (StO2) was significantly lower (58.9±12.1% vs. 70.5±9.1% for controls).ConclusionCBF was impeded in PHVD infants requiring a clinical intervention, but the effect is not large enough to alter CMRO2.
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Affiliation(s)
- Peter J McLachlan
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Jessica Kishimoto
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - Mamadou Diop
- Imaging Division, Lawson Health Research Institute, London, Ontario, Canada
| | - Daniel Milej
- Imaging Division, Lawson Health Research Institute, London, Ontario, Canada
| | - David S C Lee
- Department of Pediatrics, Western University, London, Ontario, Canada
| | | | - Keith St Lawrence
- Imaging Division, Lawson Health Research Institute, London, Ontario, Canada
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Ferradal SL, Yuki K, Vyas R, Ha CG, Yi F, Stopp C, Wypij D, Cheng HH, Newburger JW, Kaza AK, Franceschini MA, Kussman BD, Grant PE. Non-invasive Assessment of Cerebral Blood Flow and Oxygen Metabolism in Neonates during Hypothermic Cardiopulmonary Bypass: Feasibility and Clinical Implications. Sci Rep 2017; 7:44117. [PMID: 28276534 PMCID: PMC5343476 DOI: 10.1038/srep44117] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 02/02/2017] [Indexed: 02/01/2023] Open
Abstract
The neonatal brain is extremely vulnerable to injury during periods of hypoxia and/or ischemia. Risk of brain injury is increased during neonatal cardiac surgery, where pre-existing hemodynamic instability and metabolic abnormalities are combined with long periods of low cerebral blood flow and/or circulatory arrest. Our understanding of events associated with cerebral hypoxia-ischemia during cardiopulmonary bypass (CPB) remains limited, largely due to inadequate tools to quantify cerebral oxygen delivery and consumption non-invasively and in real-time. This pilot study aims to evaluate cerebral blood flow (CBF) and oxygen metabolism (CMRO2) intraoperatively in neonates by combining two novel non-invasive optical techniques: frequency-domain near-infrared spectroscopy (FD-NIRS) and diffuse correlation spectroscopy (DCS). CBF and CMRO2 were quantified before, during and after deep hypothermic cardiopulmonary bypass (CPB) in nine neonates. Our results show significantly decreased CBF and CMRO2 during hypothermic CPB. More interestingly, a change of coupling between both variables is observed during deep hypothermic CPB in all subjects. Our results are consistent with previous studies using invasive techniques, supporting the concept of FD-NIRS/DCS as a promising technology to monitor cerebral physiology in neonates providing the potential for individual optimization of surgical management.
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Affiliation(s)
- Silvina L Ferradal
- Fetal-Neonatal Neuroimaging &Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Koichi Yuki
- Department of Anesthesiology, Perioperative &Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Rutvi Vyas
- Fetal-Neonatal Neuroimaging &Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Christopher G Ha
- Fetal-Neonatal Neuroimaging &Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Francesca Yi
- Fetal-Neonatal Neuroimaging &Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Christian Stopp
- Department of Cardiology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - David Wypij
- Department of Cardiology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Henry H Cheng
- Department of Cardiology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Jane W Newburger
- Department of Cardiology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Aditya K Kaza
- Department of Cardiovascular Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Maria A Franceschini
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Barry D Kussman
- Department of Anesthesiology, Perioperative &Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - P Ellen Grant
- Fetal-Neonatal Neuroimaging &Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Verdecchia K, Diop M, Lee A, Morrison LB, Lee TY, St. Lawrence K. Assessment of a multi-layered diffuse correlation spectroscopy method for monitoring cerebral blood flow in adults. BIOMEDICAL OPTICS EXPRESS 2016; 7:3659-3674. [PMID: 27699127 PMCID: PMC5030039 DOI: 10.1364/boe.7.003659] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/22/2016] [Accepted: 07/26/2016] [Indexed: 05/21/2023]
Abstract
Diffuse correlation spectroscopy (DCS) is a promising technique for brain monitoring as it can provide a continuous signal that is directly related to cerebral blood flow (CBF); however, signal contamination from extracerebral tissue can cause flow underestimations. The goal of this study was to investigate whether a multi-layered (ML) model that accounts for light propagation through the different tissue layers could successfully separate scalp and brain flow when applied to DCS data acquired at multiple source-detector distances. The method was first validated with phantom experiments. Next, experiments were conducted in a pig model of the adult head with a mean extracerebral tissue thickness of 9.8 ± 0.4 mm. Reductions in CBF were measured by ML DCS and computed tomography perfusion for validation; excellent agreement was observed by a mean difference of 1.2 ± 4.6% (CI95%: -31.1 and 28.6) between the two modalities, which was not significantly different.
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Affiliation(s)
- Kyle Verdecchia
- Imaging Program, Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
- Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Mamadou Diop
- Imaging Program, Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
- Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Albert Lee
- Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Laura B. Morrison
- Imaging Program, Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
- Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Ting-Yim Lee
- Imaging Program, Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
- Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 3K7, Canada
- Imaging Research Laboratories, Robarts Research Institute, London, Ontario N6G 2V4, Canada
| | - Keith St. Lawrence
- Imaging Program, Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
- Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 3K7, Canada
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Johansson JD, Mireles M, Morales-Dalmau J, Farzam P, Martínez-Lozano M, Casanovas O, Durduran T. Scanning, non-contact, hybrid broadband diffuse optical spectroscopy and diffuse correlation spectroscopy system. BIOMEDICAL OPTICS EXPRESS 2016; 7:481-98. [PMID: 26977357 PMCID: PMC4771466 DOI: 10.1364/boe.7.000481] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/19/2015] [Accepted: 01/13/2016] [Indexed: 05/24/2023]
Abstract
A scanning system for small animal imaging using non-contact, hybrid broadband diffuse optical spectroscopy (ncDOS) and diffuse correlation spectroscopy (ncDCS) is presented. The ncDOS uses a two-dimensional spectrophotometer retrieving broadband (610-900 nm) spectral information from up to fifty-seven source-detector distances between 2 and 5 mm. The ncDCS data is simultaneously acquired from four source-detector pairs. The sample is scanned in two dimensions while tracking variations in height. The system has been validated with liquid phantoms, demonstrated in vivo on a human fingertip during an arm cuff occlusion and on a group of mice with xenoimplanted renal cell carcinoma.
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Affiliation(s)
- Johannes D. Johansson
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Sciences and Technology, 08860, Castelldefels (Barcelona), Spain
| | - Miguel Mireles
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Sciences and Technology, 08860, Castelldefels (Barcelona), Spain
| | - Jordi Morales-Dalmau
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Sciences and Technology, 08860, Castelldefels (Barcelona), Spain
| | - Parisa Farzam
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Sciences and Technology, 08860, Castelldefels (Barcelona), Spain
| | - Mar Martínez-Lozano
- Program Against Cancer Therapeutic Resistance (ProCURE), Catalan Institute of Oncology, Bellvitge Biomedical Research Institute–IDIBELL, 08908, L’Hospitalet de Llobregat (Barcelona), Spain
| | - Oriol Casanovas
- Program Against Cancer Therapeutic Resistance (ProCURE), Catalan Institute of Oncology, Bellvitge Biomedical Research Institute–IDIBELL, 08908, L’Hospitalet de Llobregat (Barcelona), Spain
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Sciences and Technology, 08860, Castelldefels (Barcelona), Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08015 Barcelona, Spain
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Verdecchia K, Diop M, Morrison LB, Lee TY, St. Lawrence K. Assessment of the best flow model to characterize diffuse correlation spectroscopy data acquired directly on the brain. BIOMEDICAL OPTICS EXPRESS 2015; 6:4288-301. [PMID: 26600995 PMCID: PMC4646539 DOI: 10.1364/boe.6.004288] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 10/02/2015] [Accepted: 10/04/2015] [Indexed: 05/23/2023]
Abstract
Diffuse correlation spectroscopy (DCS) is a non-invasive optical technique capable of monitoring tissue perfusion. The normalized temporal intensity autocorrelation function generated by DCS is typically characterized by assuming that the movement of erythrocytes can be modeled as a Brownian diffusion-like process instead of by the expected random flow model. Recently, a hybrid model, referred to as the hydrodynamic diffusion model, was proposed, which combines the random and Brownian flow models. The purpose of this study was to investigate the best model to describe autocorrelation functions acquired directly on the brain in order to avoid confounding effects of extracerebral tissues. Data were acquired from 11 pigs during normocapnia and hypocapnia, and flow changes were verified by computed tomography perfusion (CTP). The hydrodynamic diffusion model was found to provide the best fit to the autocorrelation functions; however, no significant difference for relative flow changes measured by the Brownian and hydrodynamic diffusion models was observed.
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Affiliation(s)
- Kyle Verdecchia
- Imaging Division, Lawson Health Research Institute, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond Street North, London, ON N6A 5C1, Canada
| | - Mamadou Diop
- Imaging Division, Lawson Health Research Institute, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond Street North, London, ON N6A 5C1, Canada
| | - Laura B. Morrison
- Imaging Division, Lawson Health Research Institute, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond Street North, London, ON N6A 5C1, Canada
| | - Ting-Yim Lee
- Imaging Division, Lawson Health Research Institute, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond Street North, London, ON N6A 5C1, Canada
- Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, ON N6G 2V4, Canada
| | - Keith St. Lawrence
- Imaging Division, Lawson Health Research Institute, 268 Grosvenor Street, London, ON N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond Street North, London, ON N6A 5C1, Canada
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