1
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Chen DY, Di X, Yu X, Biswal BB. The significance and limited influence of cerebrovascular reactivity on age and sex effects in task- and resting-state brain activity. Cereb Cortex 2024; 34:bhad448. [PMID: 38212284 PMCID: PMC10832986 DOI: 10.1093/cercor/bhad448] [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: 09/01/2023] [Accepted: 10/31/2023] [Indexed: 01/13/2024] Open
Abstract
Functional MRI measures the blood-oxygen-level dependent signals, which provide an indirect measure of neural activity mediated by neurovascular responses. Cerebrovascular reactivity affects both task-induced and resting-state blood-oxygen-level dependent activity and may confound inter-individual effects, such as those related to aging and biological sex. We examined a large dataset containing breath-holding, checkerboard, and resting-state tasks. We used the breath-holding task to measure cerebrovascular reactivity, used the checkerboard task to obtain task-based activations, and quantified resting-state activity with amplitude of low-frequency fluctuations and regional homogeneity. We hypothesized that cerebrovascular reactivity would be correlated with blood-oxygen-level dependent measures and that accounting for these correlations would result in better estimates of age and sex effects. We found that cerebrovascular reactivity was correlated with checkerboard task activations in the visual cortex and with amplitude of low-frequency fluctuations and regional homogeneity in widespread fronto-parietal regions, as well as regions with large vessels. We also found significant age and sex effects in cerebrovascular reactivity, some of which overlapped with those observed in amplitude of low-frequency fluctuations and regional homogeneity. However, correcting for the effects of cerebrovascular reactivity had very limited influence on the estimates of age and sex. Our results highlight the limitations of accounting for cerebrovascular reactivity with the current breath-holding task.
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Affiliation(s)
- Donna Y Chen
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, United States
- Rutgers Biomedical and Health Sciences, Rutgers School of Graduate Studies, Newark, NJ 08901, United States
| | - Xin Di
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, United States
| | - Xin Yu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA 02114, United States
| | - Bharat B Biswal
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, United States
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2
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Chen DY, Di X, Yu X, Biswal BB. The Significance and Limited Influence of Cerebrovascular Reactivity on Age and Sex Effects in Task- and Resting-State Brain Activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.18.553848. [PMID: 37662201 PMCID: PMC10473673 DOI: 10.1101/2023.08.18.553848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Functional MRI (fMRI) measures the blood-oxygen-level dependent (BOLD) signals, which provide an indirect measure of neural activity mediated by neurovascular responses. Cerebrovascular reactivity affects both task-induced and resting-state BOLD activity and may confound inter-individual effects observed in BOLD-based measures, such as those related to aging and biological sex. To investigate this, we examined a large open-access fMRI dataset containing a breath-holding task, checkerboard task, and resting-state scans. We used the breath-holding task to measure cerebrovascular reactivity, used the checkerboard task to obtain task-based activations, and from the resting-state data, we quantified the resting-state amplitude of low-frequency fluctuations (ALFF), and resting-state regional homogeneity (ReHo). We hypothesized that cerebrovascular reactivity would be correlated with BOLD measures and that accounting for these correlations would result in better estimates of age and sex effects. Our analysis showed that cerebrovascular reactivity was correlated with checkerboard task activations in the visual cortex and with ALFF and ReHo in widespread fronto-parietal regions, as well as regions with large vessels. We also found significant age and sex effects in cerebrovascular reactivity, some of which overlapped with those observed in ALFF and ReHo scores. Finally, we demonstrated that correcting for the effects of cerebrovascular reactivity had very limited influence on the estimates of age and sex. Our results highlight the limitations of accounting for cerebrovascular reactivity with the current breath-holding task.
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Affiliation(s)
- Donna Y. Chen
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, USA
- Rutgers Biomedical and Health Sciences, Rutgers School of Graduate Studies, Newark, NJ, USA
| | - Xin Di
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, USA
| | - Xin Yu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - Bharat B. Biswal
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, USA
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3
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Sokolov AY, Volynsky MA, Potapenko AV, Iurkova PM, Zaytsev VV, Nippolainen E, Kamshilin AA. Duality in response of intracranial vessels to nitroglycerin revealed in rats by imaging photoplethysmography. Sci Rep 2023; 13:11928. [PMID: 37488233 PMCID: PMC10366118 DOI: 10.1038/s41598-023-39171-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 07/20/2023] [Indexed: 07/26/2023] Open
Abstract
Among numerous approaches to the study of migraine, the nitroglycerin (NTG) model occupies a prominent place, but there is relatively insufficient information about how NTG affects intracranial vessels. In this study we aim to assess the effects of NTG on blood-flow parameters in meningeal vessels measured by imaging photoplethysmography (iPPG) in animal experiments. An amplitude of the pulsatile component (APC) of iPPG waveform was assessed before and within 2.5 h after the NTG administration in saline (n = 13) or sumatriptan (n = 12) pretreatment anesthetized rats in conditions of a closed cranial window. In animals of both groups, NTG caused a steady decrease in blood pressure. In 7 rats of the saline group, NTG resulted in progressive increase in APC, whereas decrease in APC was observed in other 6 rats. In all animals in the sumatriptan group, NTG administration was accompanied exclusively by an increase in APC. Diametrically opposite changes in APC due to NTG indicate a dual effect of this drug on meningeal vasomotor activity. Sumatriptan acts as a synergist of the NTG vasodilating action. The results we obtained contribute to understanding the interaction of vasoactive drugs in the study of the headache pathophysiology and methods of its therapy.
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Affiliation(s)
- Alexey Y Sokolov
- Department of Neuropharmacology, Valdman Institute of Pharmacology, Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russia
- Laboratory of Cortico-Visceral Physiology, Pavlov Institute of Physiology of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Maxim A Volynsky
- School of Physics and Engineering, ITMO University, Saint Petersburg, Russia
- Laboratory of Functional Materials and Systems for Photonics, Institute of Automation and Control Processes of Far East Branch of the Russian Academy of Sciences, Vladivostok, Russia
| | - Anastasiia V Potapenko
- Department of Neuropharmacology, Valdman Institute of Pharmacology, Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russia
- Laboratory of Biochemistry, Medical Genetic Center, Saint Petersburg, Russia
| | - Polina M Iurkova
- Laboratory of Functional Materials and Systems for Photonics, Institute of Automation and Control Processes of Far East Branch of the Russian Academy of Sciences, Vladivostok, Russia
- Faculty of General Therapy, Saint Petersburg State Pediatric Medical University, Saint Petersburg, Russia
| | - Valeriy V Zaytsev
- Laboratory of Functional Materials and Systems for Photonics, Institute of Automation and Control Processes of Far East Branch of the Russian Academy of Sciences, Vladivostok, Russia
| | - Ervin Nippolainen
- Laboratory of Functional Materials and Systems for Photonics, Institute of Automation and Control Processes of Far East Branch of the Russian Academy of Sciences, Vladivostok, Russia
| | - Alexei A Kamshilin
- Laboratory of Functional Materials and Systems for Photonics, Institute of Automation and Control Processes of Far East Branch of the Russian Academy of Sciences, Vladivostok, Russia.
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4
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Evanoff NG, Mueller BA, Marlatt KL, Geijer JR, Lim KO, Dengel DR. Reproducibility of a ramping protocol to measure cerebral vascular reactivity using functional magnetic resonance imaging. Clin Physiol Funct Imaging 2020; 40:183-189. [PMID: 31984617 DOI: 10.1111/cpf.12621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 12/14/2019] [Accepted: 01/21/2020] [Indexed: 11/29/2022]
Abstract
Though individual differences in arterial carbon dioxide and oxygen levels inherently exist, the degree of their influence on cerebral vascular reactivity (CVR) is less clear. We examined the reproducibility of BOLD signal changes to an iso-oxic ramping Pet CO2 protocol. CVR changes were induced by altering Pet CO2 while holding Pet O2 constant using a computer-controlled sequential gas delivery (SGD) device. Two MRI scans, each including a linear change in Pet CO2 , were performed using a 3-Tesla (3T) scanner. This ramp sequence consisted of 1 min at 30 mmHg followed by 4 min period during where Pet CO2 was linearly increased from 30 to 50 mmHg, 1 min at 51 mmHg, and concluded with 4 min at baseline. The protocol was repeated at a separate visit with 3 days between visits (minimum). Intraclass correlation coefficients (ICC) and coefficients of variation (CV) were used to verify reproducibility. Eleven subjects (6 females; mean age 26.5 ± 5.7 years) completed the full testing protocol. Good reproducibility was observed for the within-visit ramp sequence (Visit 1: ICC = 0.82, CV = 6.5%; Visit 2: ICC = 0.74, CV = 6.4%). Similarly, ramp sequence were reproducible between visits (Scan 1: ICC = 0.74, CV = 6.5%; Scan 2: ICC = 0.66, CV = 6.1%). Establishing reproducible methodologies for measuring BOLD signal changes in response to Pet CO2 alterations using a ramp protocol will allow researchers to study CVR functionality. Finally, adding a ramping protocol to CVR studies could provide information about changes in CVR over a broad range of Pet CO2 .
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Affiliation(s)
| | - Bryon A Mueller
- Department of Psychiatry, University of Minnesota, Minneapolis, Minnesota
| | - Kara L Marlatt
- Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Justin R Geijer
- Department of Health, Exercise and Rehabilitative Sciences, Winona State University, Winona, Minnesota
| | - Kelvin O Lim
- Department of Psychiatry, University of Minnesota, Minneapolis, Minnesota
| | - Donald R Dengel
- School of Kinesiology, University of Minnesota, Minneapolis, Minnesota.,Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota
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5
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Demartini C, Greco R, Zanaboni AM, Sances G, De Icco R, Borsook D, Tassorelli C. Nitroglycerin as a comparative experimental model of migraine pain: From animal to human and back. Prog Neurobiol 2019; 177:15-32. [DOI: 10.1016/j.pneurobio.2019.02.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 01/19/2019] [Accepted: 02/10/2019] [Indexed: 12/13/2022]
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6
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Arngrim N, Hougaard A, Schytz HW, Vestergaard MB, Britze J, Amin FM, Olsen KS, Larsson HB, Olesen J, Ashina M. Effect of hypoxia on BOLD fMRI response and total cerebral blood flow in migraine with aura patients. J Cereb Blood Flow Metab 2019; 39:680-689. [PMID: 28686073 PMCID: PMC6446416 DOI: 10.1177/0271678x17719430] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Experimentally induced hypoxia triggers migraine and aura attacks in patients suffering from migraine with aura (MA). We investigated the blood oxygenation level-dependent (BOLD) signal response to visual stimulation during hypoxia in MA patients and healthy volunteers. In a randomized double-blind crossover study design, 15 MA patients were allocated to 180 min of normobaric poikilocapnic hypoxia (capillary oxygen saturation 70-75%) or sham (normoxia) on two separate days and 14 healthy volunteers were exposed to hypoxia. The BOLD functional MRI (fMRI) signal response to visual stimulation was measured in the visual cortex ROIs V1-V5. Total cerebral blood flow (CBF) was calculated by measuring the blood velocity in the internal carotid arteries and the basilar artery using phase-contrast mapping (PCM) MRI. Hypoxia induced a greater decrease in BOLD response to visual stimulation in V1-V4 in MA patients compared to controls. There was no group difference in hypoxia-induced total CBF increase. In conclusion, the study demonstrated a greater hypoxia-induced decrease in BOLD response to visual stimulation in MA patients. We suggest this may represent a hypoxia-induced change in neuronal excitability or abnormal vascular response to visual stimulation, which may explain the increased sensibility to hypoxia in these patients leading to migraine attacks.
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Affiliation(s)
- Nanna Arngrim
- 1 Danish Headache Center and Department of Neurology, University of Copenhagen, Copenhagen, Denmark
| | - Anders Hougaard
- 1 Danish Headache Center and Department of Neurology, University of Copenhagen, Copenhagen, Denmark
| | - Henrik W Schytz
- 1 Danish Headache Center and Department of Neurology, University of Copenhagen, Copenhagen, Denmark
| | - Mark B Vestergaard
- 2 Department of Clinical Physiology, Nuclear Medicine and PET, Functional Imaging Unit, University of Copenhagen, Copenhagen, Denmark
| | - Josefine Britze
- 1 Danish Headache Center and Department of Neurology, University of Copenhagen, Copenhagen, Denmark
| | - Faisal Mohammad Amin
- 1 Danish Headache Center and Department of Neurology, University of Copenhagen, Copenhagen, Denmark
| | - Karsten S Olsen
- 3 Department of Neuroanaesthesiology, The Neuroscience Centre, Rigshospitalet Glostrup, Faculty of Health and Medical Sciences, University of Copenhagen, Glostrup, Denmark
| | - Henrik Bw Larsson
- 2 Department of Clinical Physiology, Nuclear Medicine and PET, Functional Imaging Unit, University of Copenhagen, Copenhagen, Denmark
| | - Jes Olesen
- 1 Danish Headache Center and Department of Neurology, University of Copenhagen, Copenhagen, Denmark
| | - Messoud Ashina
- 1 Danish Headache Center and Department of Neurology, University of Copenhagen, Copenhagen, Denmark
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7
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Zhao F, Zhang H, Rekik I, An Z, Shen D. Diagnosis of Autism Spectrum Disorders Using Multi-Level High-Order Functional Networks Derived From Resting-State Functional MRI. Front Hum Neurosci 2018; 12:184. [PMID: 29867410 PMCID: PMC5960713 DOI: 10.3389/fnhum.2018.00184] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 04/17/2018] [Indexed: 11/13/2022] Open
Abstract
Functional brain networks derived from resting-state functional magnetic resonance imaging (rs-fMRI) have been widely used for Autism Spectrum Disorder (ASD) diagnosis. Typically, these networks are constructed by calculating functional connectivity (FC) between any pair of brain regions of interest (ROIs), i.e., using Pearson's correlation between rs-fMRI time series. However, this can only be called as a low-order representation of the functional interaction, because the relationship is investigated just between two ROIs. Brain disorders might not only affect low-order FC, but also high-order FC, i.e., the higher-level relationship among multiple brain regions, which might be more crucial for diagnosis. To comprehensively characterize such relationship for better diagnosis of ASD, we propose a multi-level, high-order FC network representation that can nicely capture complex interactions among brain regions. Then, we design a feature selection method to identify those discriminative multi-level, high-order FC features for ASD diagnosis. Finally, we design an ensemble classifier with multiple linear SVMs, each trained on a specific level of FC networks, for boosting the final classification accuracy. Experimental results show that the integration of both low-order and first-level high-order FC networks achieves the best ASD diagnostic accuracy (81%). We further investigated those selected discriminative low-order and high-order FC features and found that the high-order FC features can provide complementary information to the low-order FC features in the ASD diagnosis.
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Affiliation(s)
- Feng Zhao
- School of Computer Science and Technology, Shandong Technology and Business University, Yantai, China
| | - Han Zhang
- Department of Radiology and BRIC, University of North Carolina, Chapel Hill, NC, United States
| | - Islem Rekik
- BASIRA Lab, CVIP Group, Computing, School of Science and Engineering, University of Dundee, Dundee, United Kingdom
| | - Zhiyong An
- School of Computer Science and Technology, Shandong Technology and Business University, Yantai, China
| | - Dinggang Shen
- Department of Radiology and BRIC, University of North Carolina, Chapel Hill, NC, United States.,Department of Brain and Cognitive Engineering, Korea University, Seoul, South Korea
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8
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Quantitative mapping of cerebrovascular reactivity using resting-state BOLD fMRI: Validation in healthy adults. Neuroimage 2016; 138:147-163. [PMID: 27177763 DOI: 10.1016/j.neuroimage.2016.05.025] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 05/04/2016] [Accepted: 05/07/2016] [Indexed: 11/23/2022] Open
Abstract
In conventional neuroimaging, cerebrovascular reactivity (CVR) is quantified primarily using the blood-oxygenation level-dependent (BOLD) functional MRI (fMRI) signal, specifically, as the BOLD response to intravascular carbon dioxide (CO2) modulations, in units of [%ΔBOLD/mmHg]. While this method has achieved wide appeal and clinical translation, the tolerability of CO2-related tasks amongst patients and the elderly remains a challenge in more routine and large-scale applications. In this work, we propose an improved method to quantify CVR by exploiting intrinsic fluctuations in CO2 and corresponding changes in the resting-state BOLD signal (rs-qCVR). Our rs-qCVR approach requires simultaneous monitoring of PETCO2, cardiac pulsation and respiratory volume. In 16 healthy adults, we compare our quantitative CVR estimation technique to the prospective CO2-targeting based CVR quantification approach (qCVR, the "standard"). We also compare our rs-CVR to non-quantitative alternatives including the resting-state fluctuation amplitude (RSFA), amplitude of low-frequency fluctuation (ALFF) and global-signal regression. When all subjects were pooled, only RSFA and ALFF were significantly associated with qCVR. However, for characterizing regional CVR variations within each subject, only the PETCO2-based rs-qCVR measure is strongly associated with standard qCVR in 100% of the subjects (p≤0.1). In contrast, for the more qualitative CVR measures, significant within-subject association with qCVR was only achieved in 50-70% of the subjects. Our work establishes the feasibility of extracting quantitative CVR maps using rs-fMRI, opening the possibility of mapping functional connectivity and qCVR simultaneously.
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9
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Dengel DR, Evanoff NG, Marlatt KL, Geijer JR, Mueller BA, Lim KO. Reproducibility of blood oxygen level-dependent signal changes with end-tidal carbon dioxide alterations. Clin Physiol Funct Imaging 2016; 37:794-798. [PMID: 26934185 DOI: 10.1111/cpf.12358] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 02/05/2016] [Indexed: 11/29/2022]
Abstract
Hypercapnia has been utilized as a stimulus to elicit changes in cerebral blood flow (CBF). However, in many instances it has been delivered in a non-controlled method that is often difficult to reproduce. The purpose of this study was to examine the within- and between-visit reproducibility of blood oxygen level-dependent (BOLD) signal changes to an iso-oxic square wave alteration in end-tidal carbon dioxide partial pressure (Pet CO2 ). Two 3-Tesla (3T) MRI scans were performed on the same visit, with two square wave alterations administered per scan. The protocol was repeated on a separate visit with minimum of 3 days between scanning sessions. Pet CO2 was altered to stimulate changes in cerebral vascular reactivity (CVR), while Pet O2 was held constant. Eleven subjects (six females; mean age 26·5 ± 5·7 years) completed the full testing protocol. Excellent within-visit square wave reproducibility (ICC > 0·75) was observed. Similarly, square waves were reproducible between scanning sessions (ICC > 0·7). This study demonstrates BOLD signal changes in response to alterations in Pet CO2 are reproducible both within- and between-visit MRI scans.
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Affiliation(s)
- Donald R Dengel
- School of Kinesiology, University of Minnesota, Minneapolis, MN, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA
| | | | - Kara L Marlatt
- School of Kinesiology, University of Minnesota, Minneapolis, MN, USA
| | - Justin R Geijer
- Department of Health, Exercise and Rehabilitative Sciences, Winona State University, Winona, MN, USA
| | - Bryon A Mueller
- Department of Psychiatry, University of Minnesota, Minneapolis, MN, USA
| | - Kelvin O Lim
- Department of Psychiatry, University of Minnesota, Minneapolis, MN, USA
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10
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Carl J, Tideman DA, Ravn S, Lund K, Magnisdottir SO, Kjærgaard B. Intravenous Infusion of Nitroglycerine Leads to Increased Permeability on Dynamic Contrast-Enhanced MR Imaging in Pig Brains. AJNR Am J Neuroradiol 2015; 36:1288-92. [PMID: 25814659 DOI: 10.3174/ajnr.a4279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 01/02/2015] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE It has been suggested that off-label use of transdermal nitroglycerine patches to prevent frostbite may lead to severe acute mountain sickness and ataxia. The aim of this study was to investigate the effect of nitroglycerine on brain vascular permeability by using dynamic contrast-enhanced MR imaging in a swine model. MATERIALS AND METHODS Eight Danish Landrace-Yorkshire-Danish Landrace pigs of approximately 20-25 kg were scanned with a dynamic contrast-enhanced MR perfusion protocol with and without nitroglycerine intravenous infusion. Compartmental analysis was performed on the basis of the Tofts model, and voxel-based quantitative values of the volume transfer constants from the vascular to the extracellular space were determined. RESULTS The scan with nitroglycerine infusion resulted in significantly higher volume transfer constant values than values derived from the first scan without nitroglycerine infusion. Increased volume transfer constant values were observed in 6 of 8 animals. CONCLUSIONS Infusion of nitroglycerine increases the vascular permeability of the swine brain on the basis of the transfer constant estimated from dynamic contrast-enhanced MR imaging.
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Affiliation(s)
- J Carl
- From the Department of Medical Physics, Oncology (J.C., D.A.T., S.R., K.L.)
| | - D A Tideman
- From the Department of Medical Physics, Oncology (J.C., D.A.T., S.R., K.L.)
| | - S Ravn
- From the Department of Medical Physics, Oncology (J.C., D.A.T., S.R., K.L.)
| | - K Lund
- From the Department of Medical Physics, Oncology (J.C., D.A.T., S.R., K.L.)
| | - S O Magnisdottir
- Biomedical Research Laboratory (S.O.M., B.K.), Aalborg University Hospital, Aalborg, Denmark
| | - B Kjærgaard
- Biomedical Research Laboratory (S.O.M., B.K.), Aalborg University Hospital, Aalborg, Denmark
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11
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Fierstra J, Sobczyk O, Battisti-Charbonney A, Mandell DM, Poublanc J, Crawley AP, Mikulis DJ, Duffin J, Fisher JA. Measuring cerebrovascular reactivity: what stimulus to use? J Physiol 2013; 591:5809-21. [PMID: 24081155 DOI: 10.1113/jphysiol.2013.259150] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Cerebrovascular reactivity is the change in cerebral blood flow in response to a vasodilatory or vasoconstrictive stimulus. Measuring variations of cerebrovascular reactivity between different regions of the brain has the potential to not only advance understanding of how the cerebral vasculature controls the distribution of blood flow but also to detect cerebrovascular pathophysiology. While there are standardized and repeatable methods for estimating the changes in cerebral blood flow in response to a vasoactive stimulus, the same cannot be said for the stimulus itself. Indeed, the wide variety of vasoactive challenges currently employed in these studies impedes comparisons between them. This review therefore critically examines the vasoactive stimuli in current use for their ability to provide a standard repeatable challenge and for the practicality of their implementation. Such challenges include induced reductions in systemic blood pressure, and the administration of vasoactive substances such as acetazolamide and carbon dioxide. We conclude that many of the stimuli in current use do not provide a standard stimulus comparable between individuals and in the same individual over time. We suggest that carbon dioxide is the most suitable vasoactive stimulus. We describe recently developed computer-controlled MRI compatible gas delivery systems which are capable of administering reliable and repeatable vasoactive CO2 stimuli.
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Affiliation(s)
- J Fierstra
- J. Duffin: Department of Physiology, Medical Sciences Building, 1 King's College Circle, University of Toronto, Toronto, Ontario, Canada, M5S 1A8.
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12
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Liu TT, Glover GH, Mueller BA, Greve DN, Brown GG. An introduction to normalization and calibration methods in functional MRI. PSYCHOMETRIKA 2013; 78:308-21. [PMID: 25107618 DOI: 10.1007/s11336-012-9309-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 02/15/2012] [Indexed: 05/26/2023]
Abstract
In functional magnetic resonance imaging (fMRI), the blood oxygenation level dependent (BOLD) signal is often interpreted as a measure of neural activity. However, because the BOLD signal reflects the complex interplay of neural, vascular, and metabolic processes, such an interpretation is not always valid. There is growing evidence that changes in the baseline neurovascular state can result in significant modulations of the BOLD signal that are independent of changes in neural activity. This paper introduces some of the normalization and calibration methods that have been proposed for making the BOLD signal a more accurate reflection of underlying brain activity for human fMRI studies.
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Affiliation(s)
- Thomas T Liu
- Center for Functional MRI, University of California San Diego, 9500 Gilman Drive, MC 0677, La Jolla, CA, 92093, USA,
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13
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Effects of glyceryl trinitrate and calcitonin-gene-related peptide on BOLD signal and arterial diameter –methodological studies by fMRI and MRA. J Headache Pain 2013. [PMCID: PMC3619987 DOI: 10.1186/1129-2377-14-s1-i4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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14
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Khalili-Mahani N, van Osch MJ, de Rooij M, Beckmann CF, van Buchem MA, Dahan A, van Gerven JM, Rombouts SARB. Spatial heterogeneity of the relation between resting-state connectivity and blood flow: an important consideration for pharmacological studies. Hum Brain Mapp 2012; 35:929-42. [PMID: 23281174 DOI: 10.1002/hbm.22224] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 10/08/2012] [Accepted: 10/22/2012] [Indexed: 01/28/2023] Open
Abstract
Resting state fMRI (RSfMRI) and arterial spin labeling (ASL) provide the field of pharmacological Neuroimaging tool for investigating states of brain activity in terms of functional connectivity or cerebral blood flow (CBF). Functional connectivity reflects the degree of synchrony or correlation of spontaneous fluctuations--mostly in the blood oxygen level dependent (BOLD) signal--across brain networks; but CBF reflects mean delivery of arterial blood to the brain tissue over time. The BOLD and CBF signals are linked to common neurovascular and hemodynamic mechanisms that necessitate increased oxygen transportation to the site of neuronal activation; however, the scale and the sources of variation in static CBF and spatiotemporal BOLD correlations are likely different. We tested this hypothesis by examining the relation between CBF and resting-state-network consistency (RSNC)--representing average intranetwork connectivity, determined from dual regression analysis with eight standard networks of interest (NOIs)--in a crossover placebo-controlled study of morphine and alcohol. Overall, we observed spatially heterogeneous relations between RSNC and CBF, and between the experimental factors (drug-by-time, time, drug and physiological rates) and each of these metrics. The drug-by-time effects on CBF were significant in all networks, but significant RSNC changes were limited to the sensorimotor, the executive/salience and the working memory networks. The post-hoc voxel-wise statistics revealed similar dissociations, perhaps suggesting differential sensitivity of RSNC and CBF to neuronal and vascular endpoints of drug actions. The spatial heterogeneity of RSNC/CBF relations encourages further investigation into the role of neuroreceptor distribution and cerebrovascular anatomy in predicting spontaneous fluctuations under drugs.
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Affiliation(s)
- Najmeh Khalili-Mahani
- Institute of Psychology, Leiden University, Leiden, The Netherlands; Department of Radiology, Leiden University Medical Center (LUMC), Leiden, The Netherlands; Leiden Institute for Brain and Cognition (LIBC), Leiden University, Leiden, The Netherlands
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