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Larsson HBW, Law I, Andersen TL, Andersen FL, Fischer BM, Vestergaard MB, Larsson TSW, Lindberg U. Brain perfusion estimation by Tikhonov model-free deconvolution in a long axial field of view PET/CT scanner exploring five different PET tracers. Eur J Nucl Med Mol Imaging 2024; 51:707-720. [PMID: 37843600 PMCID: PMC10796558 DOI: 10.1007/s00259-023-06469-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/03/2023] [Indexed: 10/17/2023]
Abstract
PURPOSE New total-body PET scanners with a long axial field of view (LAFOV) allow for higher temporal resolution due to higher sensitivity, which facilitates perfusion estimation by model-free deconvolution. Fundamental tracer kinetic theory predicts that perfusion can be estimated for all tracers despite their different fates given sufficiently high temporal resolution of 1 s or better, bypassing the need for compartment modelling. The aim of this study was to investigate whether brain perfusion could be estimated using model-free Tikhonov generalized deconvolution for five different PET tracers, [15O]H2O, [11C]PIB, [18F]FE-PE2I, [18F]FDG and [18F]FET. To our knowledge, this is the first example of a general model-free approach to estimate cerebral blood flow (CBF) from PET data. METHODS Twenty-five patients underwent dynamic LAFOV PET scanning (Siemens, Quadra). PET images were reconstructed with an isotropic voxel resolution of 1.65 mm3. Time framing was 40 × 1 s during bolus passage followed by increasing framing up to 60 min. AIF was obtained from the descending aorta. Both voxel- and region-based calculations of perfusion in the thalamus were performed using the Tikhonov method. The residue impulse response function was used to estimate the extraction fraction of tracer leakage across the blood-brain barrier. RESULTS CBF ranged from 37 to 69 mL blood min-1 100 mL of tissue-1 in the thalamus. Voxelwise calculation of CBF resulted in CBF maps in the physiologically normal range. The extraction fractions of [15O]H2O, [18F]FE-PE2I, [11C]PIB, [18F]FDG and [18F]FET in the thalamus were 0.95, 0.78, 0.62, 0.19 and 0.03, respectively. CONCLUSION The high temporal resolution and sensitivity associated with LAFOV PET scanners allow for noninvasive perfusion estimation of multiple tracers. The method provides an estimation of the residue impulse response function, from which the fate of the tracer can be studied, including the extraction fraction, influx constant, volume of distribution and transit time distribution, providing detailed physiological insight into normal and pathologic tissue.
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Affiliation(s)
- Henrik Bo Wiberg Larsson
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital-Rigshospitalet, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark.
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Ian Law
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
| | - Thomas L Andersen
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
| | - Flemming L Andersen
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
| | - Barbara M Fischer
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital-Rigshospitalet, Copenhagen, Denmark
| | - Mark B Vestergaard
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital-Rigshospitalet, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark
| | - Tanne S W Larsson
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital-Rigshospitalet, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark
| | - Ulrich Lindberg
- Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital-Rigshospitalet, Valdemar Hansens Vej 13, 2600, Glostrup, Denmark
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Nishikawa Y, Takahashi N, Nishikawa S, Shimamoto Y, Nishimori K, Kobayashi M, Kimura H, Tsujikawa T, Kasuno K, Mori T, Kiyono Y, Okazawa H, Iwano M. Feasibility of Renal Blood Flow Measurement Using 64Cu-ATSM PET/MRI: A Quantitative PET and MRI Study. Diagnostics (Basel) 2023; 13:diagnostics13101685. [PMID: 37238171 DOI: 10.3390/diagnostics13101685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/26/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
This study aimed to evaluate the renal blood flow (RBF) in patients with chronic kidney disease (CKD) using 64Cu(II)-diacetyl-bis(4-methylthiosemicarbazonate) (64Cu-ATSM) for positron emission tomography (PET)/magnetic resonance imaging (MRI). We included five healthy controls (HCs) and ten patients with CKD. The estimated glomerular filtration rate (eGFR) was calculated from the serum creatinine (cr) and cystatin C (cys) levels. The estimated RBF (eRBF) was calculated using the eGFR, hematocrit, and filtration fraction. A single dose of 64Cu-ATSM (300-400 MBq) was administered for RBF evaluation, and a 40 min dynamic PET scan was performed with simultaneous arterial spin labeling (ASL) imaging. PET-RBF images were obtained from the dynamic PET images at 3 min after injection using the image-derived input function method. The mean eRBF values calculated from various eGFR values differed significantly between the patients and HCs; both groups also differed significantly in terms of the RBF values (mL/min/100 g) measured using PET (151 ± 20 vs. 124 ± 22, p < 0.05) and ASL-MRI (172 ± 38 vs. 125 ± 30, p < 0.001). The ASL-MRI-RBF was positively correlated with the eRBFcr-cys (r = 0.858, p < 0.001). The PET-RBF was positively correlated with the eRBFcr-cys (r = 0.893, p < 0.001). The ASL-RBF was positively correlated with the PET-RBF (r = 0.849, p < 0.001). 64Cu-ATSM PET/MRI demonstrated the reliability of PET-RBF and ASL-RBF by comparing them with eRBF. This is the first study to demonstrate that 64Cu-ATSM-PET is useful for assessing the RBF and is well correlated with ASL-MRI.
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Affiliation(s)
- Yudai Nishikawa
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Naoki Takahashi
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Sho Nishikawa
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Yuki Shimamoto
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Kazuhisa Nishimori
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Mamiko Kobayashi
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Hideki Kimura
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Tetsuya Tsujikawa
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan
- Department of Radiology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Kenji Kasuno
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Tetsuya Mori
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan
| | - Yasushi Kiyono
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan
| | - Hidehiko Okazawa
- Biomedical Imaging Research Center, University of Fukui, Fukui 910-1193, Japan
| | - Masayuki Iwano
- Department of Nephrology, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
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Courault P, Lancelot S, Costes N, Colom M, Le Bars D, Redoute J, Gobert F, Dailler F, Isal S, Iecker T, Newman-Tancredi A, Merida I, Zimmer L. [ 18F]F13640: a selective agonist PET radiopharmaceutical for imaging functional 5-HT 1A receptors in humans. Eur J Nucl Med Mol Imaging 2023; 50:1651-1664. [PMID: 36656363 PMCID: PMC10119077 DOI: 10.1007/s00259-022-06103-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 12/27/2022] [Indexed: 01/20/2023]
Abstract
PURPOSE F13640 (a.k.a. befiradol, NLX-112) is a highly selective 5-HT1A receptor ligand that was selected as a PET radiopharmaceutical-candidate based on animal studies. Due to its high efficacy agonist properties, [18F]F13640 binds preferentially to functional 5-HT1A receptors, which are coupled to intracellular G-proteins. Here, we characterize brain labeling of 5-HT1A receptors by [18F]F13640 in humans and describe a simplified model for its quantification. METHODS PET/CT and PET-MRI scans were conducted in a total of 13 healthy male volunteers (29 ± 9 years old), with arterial input functions (AIF) (n = 9) and test-retest protocol (n = 8). Several kinetic models were compared (one tissue compartment model, two-tissue compartment model, and Logan); two models with reference region were also evaluated: simplified reference tissue model (SRTM) and the logan reference model (LREF). RESULTS [18F]F13640 showed high uptake values in raphe nuclei and cortical regions. SRTM and LREF models showed a very high correlation with kinetic models using AIF. As concerns test-retest parameters and the prolonged binding kinetics of [18F]F13640, better reproducibility, and reliability were found with the LREF method. Cerebellum white matter and frontal lobe white matter stand out as suitable reference regions. CONCLUSION The favorable brain labeling and kinetic profile of [18F]F13640, its high receptor specificity and its high efficacy agonist properties open new perspectives for studying functionally active 5-HT1A receptors, unlike previous radiopharmaceuticals that act as antagonists. [18F]F13640's kinetic properties allow injection outside of the PET scanner with delayed acquisitions, facilitating the design of innovative longitudinal protocols in neurology and psychiatry. TRIAL REGISTRATION Trial Registration EudraCT 2017-002,722-21.
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Affiliation(s)
- Pierre Courault
- Université Claude Bernard Lyon 1, CNRS, INSERM, Lyon Neuroscience Research Center, Lyon, France.,Hospices Civils de Lyon (HCL), Lyon, France
| | - Sophie Lancelot
- Université Claude Bernard Lyon 1, CNRS, INSERM, Lyon Neuroscience Research Center, Lyon, France.,Hospices Civils de Lyon (HCL), Lyon, France.,CERMEP, Bron, France
| | - Nicolas Costes
- Université Claude Bernard Lyon 1, CNRS, INSERM, Lyon Neuroscience Research Center, Lyon, France.,CERMEP, Bron, France
| | | | - Didier Le Bars
- Hospices Civils de Lyon (HCL), Lyon, France.,CERMEP, Bron, France
| | | | - Florent Gobert
- Université Claude Bernard Lyon 1, CNRS, INSERM, Lyon Neuroscience Research Center, Lyon, France.,Hospices Civils de Lyon (HCL), Lyon, France
| | | | - Sibel Isal
- Hospices Civils de Lyon (HCL), Lyon, France
| | | | | | | | - Luc Zimmer
- Université Claude Bernard Lyon 1, CNRS, INSERM, Lyon Neuroscience Research Center, Lyon, France. .,Hospices Civils de Lyon (HCL), Lyon, France. .,CERMEP, Bron, France.
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Gjedde A, Wong DF. Four decades of mapping and quantifying neuroreceptors at work in vivo by positron emission tomography. Front Neurosci 2022; 16:943512. [PMID: 36161158 PMCID: PMC9493011 DOI: 10.3389/fnins.2022.943512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/18/2022] [Indexed: 11/16/2022] Open
Abstract
Decryption of brain images is the basis for the necessary translation of the findings from imaging to information required to meet the demands of clinical intervention. Tools of brain imaging, therefore, must satisfy the conditions dictated by the needs for interpretation in terms of diagnosis and prognosis. In addition, the applications must serve as fundamental research tools that enable the understanding of new therapeutic drugs, including compounds as diverse as antipsychotics, antidepressants, anxiolytics, and drugs serving the relief of symptoms from neurochemical disorders as unrelated as multiple sclerosis, stroke, and dementia. Here we review and explain the kinetics of methods that enable researchers to describe the brain’s work and functions. We focus on methods invented by neurokineticists and expanded upon by practitioners during decades of experimental work and on the methods that are particularly useful to predict possible future approaches to the treatment of neurochemical disorders. We provide an overall description of the basic elements of kinetics and the underlying quantification methods, as well as the mathematics of modeling the recorded brain dynamics embedded in the images we obtain in vivo. The complex presentation to follow is necessary to justify the contribution of modeling to the development of methods and to support the specifications dictated by the proposed use in clinical settings. The quantification and kinetic modeling processes are equally essential to image reconstruction and labeling of brain regions of structural or functional interest. The procedures presented here are essential tools of scientific approaches to all conventional and novel forms of brain imaging. The foundations of the kinetic and quantitative methods are keys to the satisfaction of clinicians that actively engage in treating the neurochemical disorders of mammalian brains in the fields of neurology, neurosurgery, and neuropsychiatry.
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Affiliation(s)
- Albert Gjedde
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- *Correspondence: Albert Gjedde,
| | - Dean F. Wong
- Department of Radiology, Psychiatry, Neurology, and Neuroscience, Mallinckrodt Institute of Radiology, Washington University, St Louis, MO, United States
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Zeng D, Zeng C, Zeng Z, Li S, Deng Z, Chen S, Bian Z, Ma J. Basis and current state of computed tomography perfusion imaging: a review. Phys Med Biol 2022; 67. [PMID: 35926503 DOI: 10.1088/1361-6560/ac8717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 08/04/2022] [Indexed: 12/30/2022]
Abstract
Computed tomography perfusion (CTP) is a functional imaging that allows for providing capillary-level hemodynamics information of the desired tissue in clinics. In this paper, we aim to offer insight into CTP imaging which covers the basics and current state of CTP imaging, then summarize the technical applications in the CTP imaging as well as the future technological potential. At first, we focus on the fundamentals of CTP imaging including systematically summarized CTP image acquisition and hemodynamic parameter map estimation techniques. A short assessment is presented to outline the clinical applications with CTP imaging, and then a review of radiation dose effect of the CTP imaging on the different applications is presented. We present a categorized methodology review on known and potential solvable challenges of radiation dose reduction in CTP imaging. To evaluate the quality of CTP images, we list various standardized performance metrics. Moreover, we present a review on the determination of infarct and penumbra. Finally, we reveal the popularity and future trend of CTP imaging.
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Affiliation(s)
- Dong Zeng
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Cuidie Zeng
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Zhixiong Zeng
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Sui Li
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Zhen Deng
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Sijin Chen
- Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Zhaoying Bian
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
| | - Jianhua Ma
- School of Biomedical Engineering, Southern Medical University, Guangdong 510515, China; and Guangzhou Key Laboratory of Medical Radiation Imaging and Detection Technology, Southern Medical University, Guangdong 510515, People's Republic of China
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Ssali T, Narciso L, Hicks J, Liu L, Jesso S, Richardson L, Günther M, Konstandin S, Eickel K, Prato F, Anazodo UC, Finger E, St Lawrence K. Concordance of regional hypoperfusion by pCASL MRI and 15O-water PET in frontotemporal dementia: Is pCASL an efficacious alternative? Neuroimage Clin 2022; 33:102950. [PMID: 35134705 PMCID: PMC8829802 DOI: 10.1016/j.nicl.2022.102950] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 12/11/2022]
Abstract
ASL is an alternative to 15O-water for identifying hypoperfusion in FTD patients. ROI-based perfusion by ASL and 15O-water were strongly correlated (R > 0.75). Hypoperfusion patterns identified by 15O-water and ASL were in good agreement. Careful selection of the reference region is required to avoid erroneous results.
Background Clinical diagnosis of frontotemporal dementia (FTD) remains a challenge due to the overlap of symptoms among FTD subtypes and with other psychiatric disorders. Perfusion imaging by arterial spin labeling (ASL) is a promising non-invasive alternative to established PET techniques; however, its sensitivity to imaging parameters can hinder its ability to detect perfusion abnormalities. Purpose This study evaluated the similarity of regional hypoperfusion patterns detected by ASL relative to the gold standard for imaging perfusion, PET with radiolabeled water (15O-water). Methods and materials Perfusion by single-delay pseudo continuous ASL (SD-pCASL), free-lunch Hadamard encoded pCASL (FL_TE-pCASL), and 15O-water data were acquired on a hybrid PET/MR scanner in 13 controls and 9 FTD patients. Cerebral blood flow (CBF) by 15O-water was quantified by a non-invasive approach (PMRFlow). Regional hypoperfusion was determined by comparing individual patients to the control group. This was performed using absolute (aCBF) and CBF normalized to whole-brain perfusion (rCBF). Agreement was assessed based on the fraction of overlapping voxels. Sensitivity and specificity of pCASL was estimated using hypoperfused regions of interest identified by 15O-water. Results Region of interest (ROI) based perfusion measured by 15O-water strongly correlated with SD-pCASL (R = 0.85 ± 0.1) and FL_TE-pCASL (R = 0.81 ± 0.14). Good agreement in terms of regional hypoperfusion patterns was found between 15O-water and SD-pCASL (sensitivity = 70%, specificity = 78%) and between 15O-water and FL_TE-pCASL (sensitivity = 71%, specificity = 73%). However, SD-pCASL showed greater overlap (43.4 ± 21.3%) with 15O-water than FL_TE-pCASL (29.9 ± 21.3%). Although aCBF and rCBF showed no significant differences regarding spatial overlap and metrics of agreement with 15O-water, rCBF showed considerable variability across subtypes, indicating that care must be taken when selecting a reference region. Conclusions This study demonstrates the potential of pCASL for assessing regional hypoperfusion related to FTD and supports its use as a cost-effective alternative to PET.
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Affiliation(s)
- Tracy Ssali
- Lawson Health Research Institute, London, Canada; Department of Medical Biophysics, Western University, London, Canada.
| | - Lucas Narciso
- Lawson Health Research Institute, London, Canada; Department of Medical Biophysics, Western University, London, Canada
| | - Justin Hicks
- Lawson Health Research Institute, London, Canada; Department of Medical Biophysics, Western University, London, Canada
| | - Linshan Liu
- Lawson Health Research Institute, London, Canada; Department of Medical Biophysics, Western University, London, Canada
| | - Sarah Jesso
- Lawson Health Research Institute, London, Canada; St. Joseph's Health Care, London, Canada
| | - Lauryn Richardson
- Lawson Health Research Institute, London, Canada; St. Joseph's Health Care, London, Canada
| | - Matthias Günther
- Fraunhofer Institute for Medical Image Computing MEVIS, Bremen, Germany; University Bremen, Bremen, Germany
| | - Simon Konstandin
- Fraunhofer Institute for Medical Image Computing MEVIS, Bremen, Germany; Mediri GmbH, Heidelberg, Germany
| | | | - Frank Prato
- Lawson Health Research Institute, London, Canada; Department of Medical Biophysics, Western University, London, Canada
| | - Udunna C Anazodo
- Lawson Health Research Institute, London, Canada; Department of Medical Biophysics, Western University, London, Canada
| | - Elizabeth Finger
- Lawson Health Research Institute, London, Canada; Department of Medical Biophysics, Western University, London, Canada; Department of Clinical Neurological Sciences, Western University, London, Canada
| | - Keith St Lawrence
- Lawson Health Research Institute, London, Canada; Department of Medical Biophysics, Western University, London, Canada
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Puig O, Henriksen OM, Andersen FL, Lindberg U, Højgaard L, Law I, Ladefoged CN. Deep-learning-based attenuation correction in dynamic [ 15O]H 2O studies using PET/MRI in healthy volunteers. J Cereb Blood Flow Metab 2021; 41:3314-3323. [PMID: 34250821 PMCID: PMC8669198 DOI: 10.1177/0271678x211029178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Quantitative [15O]H2O positron emission tomography (PET) is the accepted reference method for regional cerebral blood flow (rCBF) quantification. To perform reliable quantitative [15O]H2O-PET studies in PET/MRI scanners, MRI-based attenuation-correction (MRAC) is required. Our aim was to compare two MRAC methods (RESOLUTE and DeepUTE) based on ultrashort echo-time with computed tomography-based reference standard AC (CTAC) in dynamic and static [15O]H2O-PET. We compared rCBF from quantitative perfusion maps and activity concentration distribution from static images between AC methods in 25 resting [15O]H2O-PET scans from 14 healthy men at whole-brain, regions of interest and voxel-wise levels. Average whole-brain CBF was 39.9 ± 6.0, 39.0 ± 5.8 and 40.0 ± 5.6 ml/100 g/min for CTAC, RESOLUTE and DeepUTE corrected studies respectively. RESOLUTE underestimated whole-brain CBF by 2.1 ± 1.50% and rCBF in all regions of interest (range -2.4%- -1%) compared to CTAC. DeepUTE showed significant rCBF overestimation only in the occipital lobe (0.6 ± 1.1%). Both MRAC methods showed excellent correlation on rCBF and activity concentration with CTAC, with slopes of linear regression lines between 0.97 and 1.01 and R2 over 0.99. In conclusion, RESOLUTE and DeepUTE provide AC information comparable to CTAC in dynamic [15O]H2O-PET but RESOLUTE is associated with a small but systematic underestimation.
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Affiliation(s)
- Oriol Puig
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Otto M Henriksen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Flemming L Andersen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Ulrich Lindberg
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Liselotte Højgaard
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Ian Law
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Claes N Ladefoged
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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Differences in Hemodynamic Alteration between Atherosclerotic Occlusive Lesions and Moyamoya Disease: A Quantitative 15O-PET Study. Diagnostics (Basel) 2021; 11:diagnostics11101820. [PMID: 34679518 PMCID: PMC8535090 DOI: 10.3390/diagnostics11101820] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 11/17/2022] Open
Abstract
To clarify the differences in hemodynamic status between atherosclerotic steno-occlusive lesions (SOL) and moyamoaya disease (MMD), hemodynamic parameters were compared using 15O-PET. Twenty-four patients with unilateral SOL (67 ± 11 y) and eighteen with MMD (33 ± 16 y) were assigned to this study. MMD patients were divided into twelve unilateral and six bilateral lesions. All patients underwent 15O-PET to measure cerebral blood flow (CBF), blood volume (CBV), oxygen extraction fraction (OEF), and metabolic rate (CMRO2). Acetazolamide was administered after the baseline scan and the second 15O-water PET was performed to evaluate cerebrovascular reactivity (CVR). For the CBF calculation in 15O-water PET, the three-weighted integral method was applied based on a one-tissue compartment model with pixel-by-pixel delay correction to measure precise CBF and arterial-to-capillary blood volume (V0). Baseline hemodynamic parameters showed significantly lower CBF, V0, and CMRO2, but greater CBV, OEF, and delay (p < 0.01) in the affected hemispheres than in the unaffected hemispheres. After ACZ administration, both hemispheres showed a significant increase in CBF (p < 0.0001), but not in V0. CVR differed significantly between the hemispheres. The arterial perfusion pressure of the functioning arterial part tended to be reduced after acetazolamide administration in patients with past neurologic events caused by hemodynamic impairment. MMD patients showed greater inactive vascular and venous volumes compared with common atherosclerotic SOL patients. The hemodynamic status of cerebral circulation may vary according to the chronic process of steno-occlusive change and the development of collateral circulation. In order to evaluate physiologic differences between the two diseases, 15O-PET with an acetazolamide challenge test is useful.
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Henriksen OM, Gjedde A, Vang K, Law I, Aanerud J, Rostrup E. Regional and interindividual relationships between cerebral perfusion and oxygen metabolism. J Appl Physiol (1985) 2021; 130:1836-1847. [PMID: 33830816 DOI: 10.1152/japplphysiol.00939.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Quantitative measurements of resting cerebral blood flow (CBF) and metabolic rate of oxygen (CMRO2) show large between-subject and regional variability, but the relationships between CBF and CMRO2 measurements regionally and globally are not fully established. Here, we investigated the between-subject and regional associations between CBF and CMRO2 measures with independent and quantitative PET techniques. We included resting CBF and CMRO2 measurements from 50 healthy volunteers (aged 22-81 yr), and calculated the regional and global values of oxygen delivery (Do2) and oxygen extraction fraction (OEF). Linear mixed-model analysis showed that CBF and CMRO2 measurements were closely associated regionally, but no significant between-subject association could be demonstrated, even when adjusting for arterial Pco2 and hemoglobin concentration. The analysis also showed regional differences of OEF, reflecting variable relationship between Do2 and CMRO2, resulting in lower estimates of OEF in thalami, brainstem, and mesial temporal cortices and higher estimates of OEF in occipital cortex. In the present study, we demonstrated no between-subject association of quantitative measurements of CBF and CMRO2 in healthy subjects. Thus, quantitative measurements of CBF did not reflect the underlying between-subject variability of oxygen metabolism measures, mainly because of large interindividual OEF variability not accounted for by Pco2 and hemoglobin concentration.NEW & NOTEWORTHY Using quantitative PET-measurements in healthy human subjects, we confirmed a regional association of CBF and CMRO2, but did not find an association of these values across subjects. This suggests that subjects have an individual coupling between perfusion and metabolism and shows that absolute perfusion measurements does not serve as a surrogate measure of individual measures of oxygen metabolism. The analysis further showed smaller, but significant regional differences of oxygen extraction fraction at rest.
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Affiliation(s)
- Otto M Henriksen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Albert Gjedde
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,Translational Neuropsychiatry Unit, Aarhus University and University Hospital, Aarhus, Denmark.,Department of Nuclear Medicine and PET Centre, Aarhus University and University Hospital, Aarhus, Denmark
| | - Kim Vang
- Department of Nuclear Medicine and PET Centre, Aarhus University and University Hospital, Aarhus, Denmark
| | - Ian Law
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Joel Aanerud
- Department of Nuclear Medicine and PET Centre, Aarhus University and University Hospital, Aarhus, Denmark
| | - Egill Rostrup
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark.,Mental Health Center Glostrup, University of Copenhagen, Copenhagen, Denmark
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10
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Ephedrine versus Phenylephrine Effect on Cerebral Blood Flow and Oxygen Consumption in Anesthetized Brain Tumor Patients: A Randomized Clinical Trial. Anesthesiology 2020; 133:304-317. [PMID: 32482999 DOI: 10.1097/aln.0000000000003377] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Studies in anesthetized patients suggest that phenylephrine reduces regional cerebral oxygen saturation compared with ephedrine. The present study aimed to quantify the effects of phenylephrine and ephedrine on cerebral blood flow and cerebral metabolic rate of oxygen in brain tumor patients. The authors hypothesized that phenylephrine reduces cerebral metabolic rate of oxygen in selected brain regions compared with ephedrine. METHODS In this double-blinded, randomized clinical trial, 24 anesthetized patients with brain tumors were randomly assigned to ephedrine or phenylephrine treatment. Positron emission tomography measurements of cerebral blood flow and cerebral metabolic rate of oxygen in peritumoral and normal contralateral regions were performed before and during vasopressor infusion. The primary endpoint was between-group difference in cerebral metabolic rate of oxygen. Secondary endpoints included changes in cerebral blood flow, oxygen extraction fraction, and regional cerebral oxygen saturation. RESULTS Peritumoral mean ± SD cerebral metabolic rate of oxygen values before and after vasopressor (ephedrine, 67.0 ± 11.3 and 67.8 ± 25.7 μmol · 100 g · min; phenylephrine, 68.2 ± 15.2 and 67.6 ± 18.0 μmol · 100 g · min) showed no intergroup difference (difference [95% CI], 1.5 [-13.3 to 16.3] μmol · 100 g · min [P = 0.839]). Corresponding contralateral hemisphere cerebral metabolic rate of oxygen values (ephedrine, 90.8 ± 15.9 and 94.6 ± 16.9 μmol · 100 g · min; phenylephrine, 100.8 ± 20.7 and 96.4 ± 17.7 μmol · 100 g · min) showed no intergroup difference (difference [95% CI], 8.2 [-2.0 to 18.5] μmol · 100 g · min [P = 0.118]). Ephedrine significantly increased cerebral blood flow (difference [95% CI], 3.9 [0.7 to 7.0] ml · 100 g · min [P = 0.019]) and regional cerebral oxygen saturation (difference [95% CI], 4 [1 to 8]% [P = 0.024]) in the contralateral hemisphere compared to phenylephrine. The change in oxygen extraction fraction in both regions (peritumoral difference [95% CI], -0.6 [-14.7 to 13.6]% [P = 0.934]; contralateral hemisphere difference [95% CI], -0.1 [- 12.1 to 12.0]% [P = 0.989]) were comparable between groups. CONCLUSIONS The cerebral metabolic rate of oxygen changes in peritumoral and normal contralateral regions were similar between ephedrine- and phenylephrine-treated patients. In the normal contralateral region, ephedrine was associated with an increase in cerebral blood flow and regional cerebral oxygen saturation compared with phenylephrine.
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11
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Puig O, Henriksen OM, Vestergaard MB, Hansen AE, Andersen FL, Ladefoged CN, Rostrup E, Larsson HB, Lindberg U, Law I. Comparison of simultaneous arterial spin labeling MRI and 15O-H 2O PET measurements of regional cerebral blood flow in rest and altered perfusion states. J Cereb Blood Flow Metab 2020; 40:1621-1633. [PMID: 31500521 PMCID: PMC7370368 DOI: 10.1177/0271678x19874643] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Arterial spin labelling (ASL) is a non-invasive magnetic resonance imaging (MRI) technique that may provide fully quantitative regional cerebral blood flow (rCBF) images. However, before its application in clinical routine, ASL needs to be validated against the clinical gold standard, 15O-H2O positron emission tomography (PET). We aimed to compare the two techniques by performing simultaneous quantitative ASL-MRI and 15O-H2O-PET examinations in a hybrid PET/MRI scanner. Duplicate rCBF measurements were performed in healthy young subjects (n = 14) in rest, during hyperventilation, and after acetazolamide (post-ACZ), yielding 63 combined PET/MRI datasets in total. Average global CBF by ASL-MRI and 15O-H2O-PET was not significantly different in any state (40.0 ± 6.5 and 40.6 ± 4.1 mL/100 g/min, respectively in rest, 24.5 ± 5.1 and 23.4 ± 4.8 mL/100 g/min, respectively, during hyperventilation, and 59.1 ± 10.4 and 64.7 ± 10.0 mL/100 g/min, respectively, post-ACZ). Overall, strong correlation between the two methods was found across all states (slope = 1.01, R2 = 0.82), while the correlations within individual states and of reactivity measures were weaker, in particular in rest (R2 = 0.05, p = 0.03). Regional distribution was similar, although ASL yielded higher perfusion and absolute reactivity in highly vascularized areas. In conclusion, ASL-MRI and 15O-H2O-PET measurements of rCBF are highly correlated across different perfusion states, but with variable correlation within and between hemodynamic states, and systematic differences in regional distribution.
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Affiliation(s)
- Oriol Puig
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Otto M Henriksen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Mark B Vestergaard
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Adam E Hansen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Flemming L Andersen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Claes N Ladefoged
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Egill Rostrup
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Henrik Bw Larsson
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Ulrich Lindberg
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
| | - Ian Law
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen, Denmark
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12
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Okazawa H, Ikawa M, Jung M, Maruyama R, Tsujikawa T, Mori T, Rahman MGM, Makino A, Kiyono Y, Kosaka H. Multimodal analysis using [ 11C]PiB-PET/MRI for functional evaluation of patients with Alzheimer's disease. EJNMMI Res 2020; 10:30. [PMID: 32232573 PMCID: PMC7105527 DOI: 10.1186/s13550-020-00619-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/19/2020] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Multimodal PET/MRI image data simultaneously obtained from patients with early-stage of Alzheimer's disease (eAD) were assessed in order to observe pathophysiologic and functional changes, as well as alterations of morphology and connectivity in the brain. Fifty-eight patients with mild cognitive impairment and early dementia (29 males, 69 ± 12 years) underwent [11C]Pittsburgh compound-B (PiB) PET/MRI with 70-min PET and MRI scans. Sixteen age-matched healthy controls (CTL) (9 males, 68 ± 11 years) were also studied with the same scanning protocol. Cerebral blood flow (CBF) was calculated from the early phase PET images using the image-derived input function method. A standardized uptake value ratio (SUVr) was calculated from 50 to 70 min PET data with a reference region of the cerebellar cortex. MR images such as 3D-T1WI, resting-state functional MRI (RS-fMRI), diffusion tensor image (DTI), and perfusion MRI acquired during the dynamic PET scan were also analyzed to evaluate various brain functions on MRI. RESULTS Twenty-seven of the 58 patients were determined as eAD based on the results of PiB-PET and clinical findings, and a total of 43 subjects' data including CTL were analyzed in this study. PiB SUVr values in all cortical regions of eAD were significantly greater than those of CTL. The PiB accumulation intensity was negatively correlated with cognitive scores. The regional PET-CBF values of eAD were significantly lower in the bilateral parietal lobes and right temporal lobe compared with CTL, but not in MRI perfusion; however, SPM showed regional differences on both PET- and MRI-CBF. SPM analysis of RS-fMRI delineated regional differences between the groups in the anterior cingulate cortex and the left precuneus. VBM analysis showed atrophic changes in the AD group in a part of the bilateral hippocampus; however, analysis of fractional anisotropy calculated from DTI data did not show differences between the two groups. CONCLUSION Multimodal analysis conducted with various image data from PiB-PET/MRI scans showed differences in regional CBF, cortical volume, and neuronal networks in different regions, indicating that pathophysiologic and functional changes in the AD brain can be observed from various aspects of neurophysiologic parameters. Application of multimodal brain images using PET/MRI would be ideal for investigating pathophysiologic changes in patients with dementia and other neurodegenerative diseases.
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Affiliation(s)
- Hidehiko Okazawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan.
| | - Masamichi Ikawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan.,Department of Neurology, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Minyoung Jung
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan.,Department of Psychiatry, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Rikiya Maruyama
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Tetsuya Tsujikawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Tetsuya Mori
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Mahmudur G M Rahman
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan.,Department of Biomedical Engineering, Khulna University of Engineering & Technology, Khulna, 9203, Bangladesh
| | - Akira Makino
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Yasushi Kiyono
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Hirotaka Kosaka
- Department of Psychiatry, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
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13
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Puig O, Vestergaard MB, Lindberg U, Hansen AE, Ulrich A, Andersen FL, Johannesen HH, Rostrup E, Law I, Larsson HBW, Henriksen OM. Phase contrast mapping MRI measurements of global cerebral blood flow across different perfusion states - A direct comparison with 15O-H 2O positron emission tomography using a hybrid PET/MR system. J Cereb Blood Flow Metab 2019; 39:2368-2378. [PMID: 30200799 PMCID: PMC6890999 DOI: 10.1177/0271678x18798762] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/25/2018] [Accepted: 07/29/2018] [Indexed: 11/29/2022]
Abstract
Phase-contrast mapping (PCM) magnetic resonance imaging (MRI) provides easy-access non-invasive quantification of global cerebral blood flow (gCBF) but its accuracy in altered perfusion states is not established. We aimed to compare paired PCM MRI and 15O-H2O positron emission tomography (PET) measurements of gCBF in different perfusion states in a single scanning session. Duplicate combined gCBF PCM-MRI and 15O-H2O PET measurements were performed in the resting condition, during hyperventilation and after acetazolamide administration (post-ACZ) using a 3T hybrid PET/MR system. A total of 62 paired gCBF measurements were acquired in 14 healthy young male volunteers. Average gCBF in resting state measured by PCM-MRI and 15O-H2O PET were 58.5 ± 10.7 and 38.6 ± 5.7 mL/100 g/min, respectively, during hyperventilation 33 ± 8.6 and 24.7 ± 5.8 mL/100 g/min, respectively, and post-ACZ 89.6 ± 27.1 and 57.3 ± 9.6 mL/100 g/min, respectively. On average, gCBF measured by PCM-MRI was 49% higher compared to 15O-H2O PET. A strong correlation between the two methods across all states was observed (R2 = 0.72, p < 0.001). Bland-Altman analysis suggested a perfusion dependent relative bias resulting in higher relative difference at higher CBF values. In conclusion, measurements of gCBF by PCM-MRI in healthy volunteers show a strong correlation with 15O-H2O PET, but are associated with a large and non-linear perfusion-dependent difference.
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Affiliation(s)
- Oriol Puig
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Mark B Vestergaard
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Ulrich Lindberg
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Adam E Hansen
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Annette Ulrich
- Department of Cardiothoracic Anesthesiology, Copenhagen University Hospital Rigshospitalet Blegdamsvej, Copenhagen, Denmark
| | - Flemming L Andersen
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Helle H Johannesen
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Egill Rostrup
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Ian Law
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Henrik BW Larsson
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Otto M Henriksen
- Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
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14
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Blazey T, Snyder AZ, Su Y, Goyal MS, Lee JJ, Vlassenko AG, Arbeláez AM, Raichle ME. Quantitative positron emission tomography reveals regional differences in aerobic glycolysis within the human brain. J Cereb Blood Flow Metab 2019; 39:2096-2102. [PMID: 29569986 PMCID: PMC6775584 DOI: 10.1177/0271678x18767005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Glucose and oxygen metabolism are tightly coupled in the human brain, with the preponderance of the brain's glucose supply used to generate ATP via oxidative phosphorylation. A fraction of glucose is consumed outside of oxidative phosphorylation despite the presence of sufficient oxygen to do so. We refer to this process as aerobic glycolysis. A recent positron emission tomography study reported that aerobic glycolysis is uniform within gray matter. Here, we analyze the same data and demonstrate robust regional differences in aerobic glycolysis within gray matter, a finding consistent with previously published data.
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Affiliation(s)
- Tyler Blazey
- Mallinckrodt Institute of Radiology, School of Medicine, Washington University, St. Louis, MO, USA
| | - Abraham Z Snyder
- Mallinckrodt Institute of Radiology, School of Medicine, Washington University, St. Louis, MO, USA.,Department of Neurology, School of Medicine, Washington University, St. Louis, MO, USA
| | - Yi Su
- Mallinckrodt Institute of Radiology, School of Medicine, Washington University, St. Louis, MO, USA
| | - Manu S Goyal
- Mallinckrodt Institute of Radiology, School of Medicine, Washington University, St. Louis, MO, USA.,Department of Neurology, School of Medicine, Washington University, St. Louis, MO, USA
| | - John J Lee
- Mallinckrodt Institute of Radiology, School of Medicine, Washington University, St. Louis, MO, USA
| | - Andrei G Vlassenko
- Mallinckrodt Institute of Radiology, School of Medicine, Washington University, St. Louis, MO, USA
| | - Ana Maria Arbeláez
- Department of Pediatrics, School of Medicine, Washington University, St. Louis, MO, USA
| | - Marcus E Raichle
- Mallinckrodt Institute of Radiology, School of Medicine, Washington University, St. Louis, MO, USA.,Department of Neurology, School of Medicine, Washington University, St. Louis, MO, USA.,Department of Biomedical Engineering, Washington University, St. Louis, MO, USA
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15
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Henriksen OM, Vestergaard MB, Lindberg U, Aachmann-Andersen NJ, Lisbjerg K, Christensen SJ, Rasmussen P, Olsen NV, Forman JL, Larsson HBW, Law I. Interindividual and regional relationship between cerebral blood flow and glucose metabolism in the resting brain. J Appl Physiol (1985) 2018; 125:1080-1089. [PMID: 29975605 DOI: 10.1152/japplphysiol.00276.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Studies of the resting brain measurements of cerebral blood flow (CBF) show large interindividual and regional variability, but the metabolic basis of this variability is not fully established. The aim of the present study was to reassess regional and interindividual relationships between cerebral perfusion and glucose metabolism in the resting brain. Regional quantitative measurements of CBF and cerebral metabolic rate of glucose (CMRglc) were obtained in 24 healthy young men using dynamic [15O]H2O and [18F]fluorodeoxyglucose positron emission tomography (PET). Magnetic resonance imaging measurements of global oxygen extraction fraction (gOEF) and metabolic rate of oxygen ([Formula: see text]) were obtained by combined susceptometry-based sagittal sinus oximetry and phase contrast mapping. No significant interindividual associations between global CBF, global CMRglc, and [Formula: see text] were observed. Linear mixed-model analysis showed a highly significant association of CBF with CMRglc regionally. Compared with neocortex significantly higher CBF values than explained by CMRglc were demonstrated in infratentorial structures, thalami, and mesial temporal cortex, and lower values were found in the striatum and cerebral white matter. The present study shows that absolute quantitative global CBF measurements appear not to be a valid surrogate measure of global cerebral glucose or oxygen consumption, and further demonstrates regionally variable relationship between perfusion and glucose metabolism in the resting brain that could suggest regional differences in energy substrate metabolism. NEW & NOTEWORTHY Using method-independent techniques the study cannot confirm direct interindividual correlations of absolute global values of perfusion with oxygen or glucose metabolism in the resting brain, and absolute global perfusion measurements appear not to be valid surrogate measures of cerebral metabolism. The ratio of both perfusion and oxygen delivery to glucose metabolism varies regionally, also when accounting for known methodological regional bias in quantification of glucose metabolism.
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Affiliation(s)
- Otto M Henriksen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen , Denmark
| | - Mark B Vestergaard
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Glostrup, Denmark
| | - Ulrich Lindberg
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Glostrup, Denmark
| | | | - Kristian Lisbjerg
- Department of Neuroanaesthesiology, The Neuroscience Centre, Rigshospitalet, Copenhagen , Denmark
| | - Søren J Christensen
- Department of Neuroanaesthesiology, The Neuroscience Centre, Rigshospitalet, Copenhagen , Denmark
| | - Peter Rasmussen
- Department of Neuroscience and Pharmacology, The Faculty of Health Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Niels V Olsen
- Department of Neuroanaesthesiology, The Neuroscience Centre, Rigshospitalet, Copenhagen , Denmark.,Department of Neuroscience and Pharmacology, The Faculty of Health Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Julie L Forman
- Section of Biostatistics, University of Copenhagen, The Faculty of Health Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Henrik B W Larsson
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Glostrup, Denmark.,Institute of Clinical Medicine, The Faculty of Health Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Ian Law
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen , Denmark.,Institute of Clinical Medicine, The Faculty of Health Sciences, University of Copenhagen , Copenhagen , Denmark
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16
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Okazawa H, Higashino Y, Tsujikawa T, Arishima H, Mori T, Kiyono Y, Kimura H, Kikuta KI. Noninvasive method for measurement of cerebral blood flow using O-15 water PET/MRI with ASL correlation. Eur J Radiol 2018; 105:102-109. [PMID: 30017265 DOI: 10.1016/j.ejrad.2018.05.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/06/2018] [Accepted: 05/31/2018] [Indexed: 10/14/2022]
Abstract
PURPOSE A noninvasive image derived input function (IDIF) method was applied to estimate arterial input function from brain H215O-PET/MRI images for the measurement of cerebral blood flow (CBF) because of difficulty in arterial blood sampling during PET/MRI scans. To evaluate accuracy and reproducibility of radioactivity in the internal carotid arteries (ICA) for the IDIF method, a new phantom using a skull bone was applied in the cross-calibration process between the scanner and a gamma-well counter. METHODS Eleven healthy volunteers (9 males, 43.9 ± 10.9y) underwent PET/MRI studies with a 3-min H215O-PET and several MRI scans including arterial spin labeling (ASL) perfusion MRI. PET images were reconstructed as dynamic data using two sets of reconstruction parameters, which were determined by basic assessment of radioactivity concentration reproducibility in the tubes of the phantom. The IDIF method extracted the time-activity curves of the ICA from several image slices in the PET data. CBF images were calculated using the autoradiographic (ARG) method and a one-tissue compartment model (1-TCM). RESULTS The global means of CBF from the ARG, 1-TCM, and ASL-MRI were 44.8 ± 4.3, 47.9 ± 5.9 and 57.9 ± 8.6 (mL/min/100 g), respectively. CBF from ASL-MRI was significantly greater compared with CBF from H215O-PET (P < 0.001). However, these CBF values were significantly correlated with each other in the scatter plots (P < 0.05). CONCLUSIONS Noninvasive measurement of CBF using H215O-PET/MRI and IDIF with the cross-calibration method with a skull phantom experiment provided reasonable quantitative values. The IDIF method allowed reliable estimation of arterial radioactivity concentration, which is useful for clinical application. The ASL-MRI perfusion image from the simultaneous acquisition tended to overestimate CBF.
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Affiliation(s)
- Hidehiko Okazawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan.
| | - Yoshifumi Higashino
- Deartment of Neurosurgery, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Tetsuya Tsujikawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Hidetaka Arishima
- Deartment of Neurosurgery, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Tetsuya Mori
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Yasushi Kiyono
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Hirohiko Kimura
- Deartment of Radiology, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Ken-Ichiro Kikuta
- Deartment of Neurosurgery, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
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17
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Svart M, Gormsen LC, Hansen J, Zeidler D, Gejl M, Vang K, Aanerud J, Moeller N. Regional cerebral effects of ketone body infusion with 3-hydroxybutyrate in humans: Reduced glucose uptake, unchanged oxygen consumption and increased blood flow by positron emission tomography. A randomized, controlled trial. PLoS One 2018; 13:e0190556. [PMID: 29489818 PMCID: PMC5830038 DOI: 10.1371/journal.pone.0190556] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 12/16/2017] [Indexed: 01/24/2023] Open
Abstract
Ketone bodies are neuroprotective in neurological disorders such as epilepsy. We randomly studied nine healthy human subjects twice—with and without continuous infusion of 3-hydroxybutyrate–to define potential underlying mechanisms, assessed regionally (parietal, occipital, temporal, cortical grey, and frontal) by PET scan. During 3-hydroxybutyrate infusions concentrations increased to 5.5±0.4 mmol/l and cerebral glucose utilisation decreased 14%, oxygen consumption remained unchanged, and cerebral blood flow increased 30%. We conclude that acute 3-hydroxybutyrate infusion reduces cerebral glucose uptake and increases cerebral blood flow in all measured brain regions, without detectable effects on cerebral oxygen uptake though oxygen extraction decreased. Increased oxygen supply concomitant with unchanged oxygen utilisation may contribute to the neuroprotective effects of ketone bodies.
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Affiliation(s)
- Mads Svart
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
- * E-mail:
| | - Lars C. Gormsen
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Jakob Hansen
- Section for Forensic Chemistry, Department of Forensic Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Dora Zeidler
- Centre of Functionally Integrative Neuroscience (CFIN) and MINDLab, Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Michael Gejl
- Institute of Biomedicine, Aarhus University, Aarhus, Denmark
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark
| | - Kim Vang
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Joel Aanerud
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Moeller
- Department of Internal Medicine and Endocrinology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
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18
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Matsunaga K, Yanagawa M, Otsuka T, Hirata H, Kijima T, Kumanogoh A, Tomiyama N, Shimosegawa E, Hatazawa J. Quantitative pulmonary blood flow measurement using 15O-H 2O PET with and without tissue fraction correction: a comparison study. EJNMMI Res 2017; 7:102. [PMID: 29274016 PMCID: PMC5741573 DOI: 10.1186/s13550-017-0350-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 12/04/2017] [Indexed: 11/23/2022] Open
Abstract
Background Physiological measures per lung parenchyma, rather than per lung volume, sometimes reflect the disease status. PET images of the lung, which are usually expressed per lung volume, could confound the interpretation of the disease status, especially in cases with a prominent heterogeneity in aeration. The aim of the present study was to develop a method for measuring pulmonary blood flow (PBF) with aeration correction using 15O-H2O PET and to compare the results with those obtained using a conventional method. We obtained the voxel-based tissue fraction (TF) derived from density images converted from transmission images obtained using an external 137Cs point source. Quantitative PBF values with and without the TF were calculated using 15O-H2O PET to examine contralateral lung tissue in 9 patients with unilateral lung cancer. The heterogeneity in PBF before and after TF correction was then evaluated and compared. As a measure of PBF heterogeneity, we used the skewness and kurtosis of the PBF distribution. Results The mean PBF of contralateral lung was 1.4 ± 0.3 mL/min per mL of lung. The TF-corrected PBF was 5.0 ± 0.6 mL/min per mL of lung parenchyma. After TF correction, the skewness and kurtosis of the PBF decreased significantly. Conclusions The present PBF calculation method using TF correction demonstrated that the normal PBF increased significantly and the PBF distribution became uniform. The proposed TF correction method is a promising technique to account for variations in density when interpreting PBF in PET studies.
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Affiliation(s)
- Keiko Matsunaga
- Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.,Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita city, Osaka, Japan
| | - Masahiro Yanagawa
- Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Tomoyuki Otsuka
- Department of Respiratory Medicine, Allergy and Rheumatic Disease, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Haruhiko Hirata
- Department of Respiratory Medicine, Allergy and Rheumatic Disease, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Takashi Kijima
- Department of Respiratory Medicine, Allergy and Rheumatic Disease, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Atsushi Kumanogoh
- Department of Respiratory Medicine, Allergy and Rheumatic Disease, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Noriyuki Tomiyama
- Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Eku Shimosegawa
- Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.,Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita city, Osaka, Japan
| | - Jun Hatazawa
- Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka Suita city, Osaka, Japan.
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19
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Koch KU, Tietze A, Aanerud J, Öettingen GV, Juul N, Sørensen JCH, Nikolajsen L, Østergaard L, Rasmussen M. Effect of ephedrine and phenylephrine on brain oxygenation and microcirculation in anaesthetised patients with cerebral tumours: study protocol for a randomised controlled trial. BMJ Open 2017; 7:e018560. [PMID: 29151054 PMCID: PMC5701991 DOI: 10.1136/bmjopen-2017-018560] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
INTRODUCTION During brain tumour surgery, vasopressor drugs are commonly administered to increase mean arterial blood pressure with the aim of maintaining sufficient cerebral perfusion pressure. Studies of the commonly used vasopressors show that brain oxygen saturation is reduced after phenylephrine administration, but unaltered by ephedrine administration. These findings may be explained by different effects of phenylephrine and ephedrine on the cerebral microcirculation, in particular the capillary transit-time heterogeneity, which determines oxygen extraction efficacy. We hypothesised that phenylephrine is associated with an increase in capillary transit-time heterogeneity and a reduction in cerebral metabolic rate of oxygen compared with ephedrine. Using MRI and positron emission tomography (PET) as measurements in anaesthetised patients with brain tumours, this study will examine whether phenylephrine administration elevates capillary transit-time heterogeneity more than ephedrine, thereby reducing brain oxygenation. METHODS AND ANALYSIS This is a double-blind, randomised clinical trial including 48 patients scheduled for surgical brain tumour removal. Prior to imaging and surgery, anaesthetised patients will be randomised to receive either phenylephrine or ephedrine infusion until mean arterial blood pressure increases to above 60 mm Hg or 20% above baseline. Twenty-four patients were allocated to MRI and another 24 patients to PET examination. MRI measurements include cerebral blood flow, capillary transit-time heterogeneity, cerebral blood volume, blood mean transit time, and calculated oxygen extraction fraction and cerebral metabolic rate of oxygen for negligible tissue oxygen extraction. PET measurements include cerebral metabolic rate of oxygen, cerebral blood flow and oxygen extraction fraction. Surgery is initiated after MRI/PET measurements and subdural intracranial pressure is measured. ETHICS AND DISSEMINATION This study was approved by the Central Denmark Region Committee on Health Research Ethics (12 June 2015; 1-10-72-116-15). Results will be disseminated via peer-reviewed publication and presentation at international conferences. TRIAL REGISTRATION NUMBER NCT02713087; Pre-results. 2015-001359-60; Pre-results.
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Affiliation(s)
- Klaus Ulrik Koch
- Department of Anesthesiology and Intensive Care-North, Section of Neuroanesthesia, Aarhus University Hospital, Aarhus, Denmark
| | - Anna Tietze
- Department of Neuroradiology and Center of Functionally Integrative Neuroscience, Aarhus University Hospital, Aarhus, Denmark
- Institute of Neuroradiology, Charite Universitatsmedizin, Berlin, Germany
| | - Joel Aanerud
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | | | - Niels Juul
- Department of Anesthesiology and Intensive Care-North, Section of Neuroanesthesia, Aarhus University Hospital, Aarhus, Denmark
| | | | - Lone Nikolajsen
- Department of Anesthesiology and Intensive Care-North, Section of Neuroanesthesia, Aarhus University Hospital, Aarhus, Denmark
| | - Leif Østergaard
- Department of Neuroradiology and Center of Functionally Integrative Neuroscience, Aarhus University Hospital, Aarhus, Denmark
| | - Mads Rasmussen
- Department of Anesthesiology and Intensive Care-North, Section of Neuroanesthesia, Aarhus University Hospital, Aarhus, Denmark
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20
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Aanerud J, Borghammer P, Rodell A, Jónsdottir KY, Gjedde A. Sex differences of human cortical blood flow and energy metabolism. J Cereb Blood Flow Metab 2017; 37:2433-2440. [PMID: 27629099 PMCID: PMC5531342 DOI: 10.1177/0271678x16668536] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 06/29/2016] [Accepted: 07/04/2016] [Indexed: 11/16/2022]
Abstract
Brain energy metabolism is held to reflect energy demanding processes in neuropil related to the density and activity of synapses. There is recent evidence that men have higher density of synapses in temporal cortex than women. One consequence of these differences would be different rates of cortical energy turnover and blood flow in men and women. To test the hypotheses that rates of oxygen consumption (CMRO2) and cerebral blood flow are higher in men than in women in regions of cerebral cortex, and that the differences persist with aging, we used positron emission tomography to determine cerebral blood flow and cerebral metabolic rate of oxygen as functions of age in healthy volunteers of both sexes. Cerebral metabolic rate of oxygen did not change with age for either sex and there were no differences of mean values of cerebral metabolic rate of oxygen between men and women in cerebral cortex. Women had significant decreases of cerebral blood flow as function of age in frontal and parietal lobes. Young women had significantly higher cerebral blood flow than men in frontal and temporal lobes, but these differences had disappeared at age 65. The absent sex difference of cerebral energy turnover suggests that the known differences of synaptic density between the sexes are counteracted by opposite differences of individual synaptic activity.
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Affiliation(s)
- Joel Aanerud
- Department of Nuclear Medicine and PET Center, Aarhus University Hospitals, Aarhus, Denmark
| | - Per Borghammer
- Department of Nuclear Medicine and PET Center, Aarhus University Hospitals, Aarhus, Denmark
| | - Anders Rodell
- Centre for Clinical Research, University of Queensland, Australia
| | | | - Albert Gjedde
- Center for Functionally Integrative Neuroscience, University of Aarhus, Aarhus, Denmark
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
- Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada
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21
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Islam MM, Tsujikawa T, Mori T, Kiyono Y, Okazawa H. Estimation of arterial input by a noninvasive image derived method in brain H 215O PET study: confirmation of arterial location using MR angiography. Phys Med Biol 2017; 62:4514-4524. [PMID: 28480872 DOI: 10.1088/1361-6560/aa6a95] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A noninvasive method to estimate input function directly from H215O brain PET data for measurement of cerebral blood flow (CBF) was proposed in this study. The image derived input function (IDIF) method extracted the time-activity curves (TAC) of the major cerebral arteries at the skull base from the dynamic PET data. The extracted primordial IDIF showed almost the same radioactivity as the arterial input function (AIF) from sampled blood at the plateau part in the later phase, but significantly lower radioactivity in the initial arterial phase compared with that of AIF-TAC. To correct the initial part of the IDIF, a dispersion function was applied and two constants for the correction were determined by fitting with the individual AIF in 15 patients with unilateral arterial stenoocclusive lesions. The area under the curves (AUC) from the two input functions showed good agreement with the mean AUCIDIF/AUCAIF ratio of 0.92 ± 0.09. The final products of CBF and arterial-to-capillary vascular volume (V 0) obtained from the IDIF and AIF showed no difference, and had with high correlation coefficients.
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Affiliation(s)
- Muhammad Muinul Islam
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui 910-1193, Japan
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22
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Islam MM, Tsujikawa T, Mori T, Kiyono Y, Okazawa H. Pixel-by-pixel precise delay correction for measurement of cerebral hemodynamic parameters in H 215O PET study. Ann Nucl Med 2017; 31:283-294. [PMID: 28243845 PMCID: PMC5397462 DOI: 10.1007/s12149-017-1156-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 01/30/2017] [Indexed: 11/25/2022]
Abstract
OBJECTIVE A new method of delay time estimation was proposed to measure precise cerebral blood flow (CBF) and arterial-to-capillary blood volume (V 0) using 15O-water PET. METHODS Nineteen patients with unilateral arterial stenoocclusive lesions were studied to evaluate hemodynamic status before treatment. The delay time of each pixel was calculated using least squares fitting with an arterial blood input curve adjusted to the internal carotid artery counts at the skull base. Pixel-by-pixel delay estimation provided a delay map image that could be used for precise calculation of CBF and V 0 using a one-tissue compartment model, and the values from this method were compared with those from the slice-by-slice correction method. RESULTS The affected side showed a longer delay time than the contralateral cerebral hemisphere. Although the mean cortical CBF values were not different between the two methods, the slice-by-slice delay correction overestimated CBF in the hypo perfused area. The scatter plot of V 0 pixel values showed significant difference between the two correction methods where the slice-by-slice delay correction significantly overestimated V 0 in the whole brain (P < 0.05). CONCLUSION Pixel-by-pixel delay correction provides delay images as well as better estimation of CBF and V 0, thus offering useful and beneficial information for the treatment of cerebrovascular disease.
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Affiliation(s)
- Muhammad M Islam
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Tetsuya Tsujikawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Tetsuya Mori
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Yasushi Kiyono
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan
| | - Hidehiko Okazawa
- Biomedical Imaging Research Center, University of Fukui, 23-3, Matsuoka-Shimaizuki, Eiheiji-cho, Fukui, 910-1193, Japan.
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23
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Jødal L, Nielsen OL, Afzelius P, Alstrup AKO, Hansen SB. Blood perfusion in osteomyelitis studied with [ 15O]water PET in a juvenile porcine model. EJNMMI Res 2017; 7:4. [PMID: 28091979 PMCID: PMC5237436 DOI: 10.1186/s13550-016-0251-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/16/2016] [Indexed: 11/20/2022] Open
Abstract
Background Osteomyelitis is a serious disease which can be difficult to treat despite properly instituted antibiotic therapy. This appears to be related at least partly to degraded vascularisation in the osteomyelitic (OM) lesions. Studies of perfusion in OM bones are, however, few and not quantitative. Quantitative assessment of perfusion could aid in the selection of therapy. A non-invasive, quantitative way to study perfusion is dynamic [15O]water positron emission tomography (PET). We aim to demonstrate that the method can be used for measuring perfusion in OM lesions and hypothesize that perfusion will be less elevated in OM lesions than in soft tissue (ST) infection. The study comprised 11 juvenile pigs with haematogenous osteomyelitis induced by injection of Staphylococcus aureus into the right femoral artery 1 week before scanning (in one pig, 2 weeks). The pigs were dynamically PET scanned with [15O]water to quantify blood perfusion. OM lesions (N = 17) in long bones were studied, using the left limb as reference. ST lesions (N = 8) were studied similarly. Results Perfusion was quantitatively determined. Perfusion was elevated by a factor 1.5 in OM lesions and by a factor 6 in ST lesions. Conclusions Blood perfusion was successfully determined in pathological subacute OM lesions; average perfusion was increased compared to that in a healthy bone, but as hypothesized, the increase was less than in ST lesions, indicating that the infected bone has less perfusion reserve than the infected soft tissue. Electronic supplementary material The online version of this article (doi:10.1186/s13550-016-0251-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lars Jødal
- Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark. .,Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark. .,Department of Nuclear Medicine, Aalborg University Hospital, P.O. Box 365, 9100, Aalborg, Denmark.
| | - Ole L Nielsen
- Department of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark
| | - Pia Afzelius
- Department of Diagnostic Imaging, North Zealand Hospital, Hillerød, Copenhagen University Hospital, Copenhagen, Denmark
| | - Aage K O Alstrup
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Søren B Hansen
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
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24
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Hyder F, Herman P, Bailey CJ, Møller A, Globinsky R, Fulbright RK, Rothman DL, Gjedde A. Uniform distributions of glucose oxidation and oxygen extraction in gray matter of normal human brain: No evidence of regional differences of aerobic glycolysis. J Cereb Blood Flow Metab 2016; 36:903-16. [PMID: 26755443 PMCID: PMC4853838 DOI: 10.1177/0271678x15625349] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 12/03/2015] [Indexed: 11/17/2022]
Abstract
Regionally variable rates of aerobic glycolysis in brain networks identified by resting-state functional magnetic resonance imaging (R-fMRI) imply regionally variable adenosine triphosphate (ATP) regeneration. When regional glucose utilization is not matched to oxygen delivery, affected regions have correspondingly variable rates of ATP and lactate production. We tested the extent to which aerobic glycolysis and oxidative phosphorylation power R-fMRI networks by measuring quantitative differences between the oxygen to glucose index (OGI) and the oxygen extraction fraction (OEF) as measured by positron emission tomography (PET) in normal human brain (resting awake, eyes closed). Regionally uniform and correlated OEF and OGI estimates prevailed, with network values that matched the gray matter means, regardless of size, location, and origin. The spatial agreement between oxygen delivery (OEF≈0.4) and glucose oxidation (OGI ≈ 5.3) suggests that no specific regions have preferentially high aerobic glycolysis and low oxidative phosphorylation rates, with globally optimal maximum ATP turnover rates (VATP ≈ 9.4 µmol/g/min), in good agreement with (31)P and (13)C magnetic resonance spectroscopy measurements. These results imply that the intrinsic network activity in healthy human brain powers the entire gray matter with ubiquitously high rates of glucose oxidation. Reports of departures from normal brain-wide homogeny of oxygen extraction fraction and oxygen to glucose index may be due to normalization artefacts from relative PET measurements.
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Affiliation(s)
- Fahmeed Hyder
- Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, USA Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, CT, USA Department of Radiology & Biomedical Imaging, Yale University, New Haven, CT, USA Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Peter Herman
- Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, USA Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, CT, USA Department of Radiology & Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Christopher J Bailey
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Arne Møller
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Ronen Globinsky
- Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, USA Department of Radiology & Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Robert K Fulbright
- Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, USA Department of Radiology & Biomedical Imaging, Yale University, New Haven, CT, USA
| | - Douglas L Rothman
- Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, USA Quantitative Neuroscience with Magnetic Resonance (QNMR) Core Center, Yale University, New Haven, CT, USA Department of Radiology & Biomedical Imaging, Yale University, New Haven, CT, USA Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Albert Gjedde
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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25
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Heijtel DFR, Petersen ET, Mutsaerts HJMM, Bakker E, Schober P, Stevens MF, van Berckel BNM, Majoie CBLM, Booij J, van Osch MJP, van Bavel ET, Boellaard R, Lammertsma AA, Nederveen AJ. Quantitative agreement between [(15)O]H2O PET and model free QUASAR MRI-derived cerebral blood flow and arterial blood volume. NMR IN BIOMEDICINE 2016; 29:519-526. [PMID: 26876426 DOI: 10.1002/nbm.3480] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/13/2015] [Accepted: 12/08/2015] [Indexed: 06/05/2023]
Abstract
The purpose of this study was to assess whether there was an agreement between quantitative cerebral blood flow (CBF) and arterial cerebral blood volume (CBVA) measurements by [(15)O]H2O positron emission tomography (PET) and model-free QUASAR MRI. Twelve healthy subjects were scanned within a week in separate MRI and PET imaging sessions, after which quantitative and qualitative agreement between both modalities was assessed for gray matter, white matter and whole brain region of interests (ROI). The correlation between CBF measurements obtained with both modalities was moderate to high (r(2): 0.28-0.60, P < 0.05), although QUASAR significantly underestimated CBF by 30% (P < 0.001). CBVA was moderately correlated (r(2): 0.28-0.43, P < 0.05), with QUASAR yielding values that were only 27% of the [(15)O]H2O-derived values (P < 0.001). Group-wise voxel statistics identified minor areas with significant contrast differences between [(15)O]H2O PET and QUASAR MRI, indicating similar qualitative CBVA and CBF information by both modalities. In conclusion, the results of this study demonstrate that QUASAR MRI and [(15)O]H2O PET provide similar CBF and CBVA information, but with systematic quantitative discrepancies.
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Affiliation(s)
- D F R Heijtel
- Department of Radiology, Academic Medical Center, Amsterdam, the Netherlands
| | - E T Petersen
- Department of Radiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - H J M M Mutsaerts
- Department of Radiology, Academic Medical Center, Amsterdam, the Netherlands
| | - E Bakker
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, the Netherlands
| | - P Schober
- Department of Anesthesiology, VU University Medical Center, Amsterdam, the Netherlands
| | - M F Stevens
- Department of Anesthesiology, Academic Medical Center, Amsterdam, the Netherlands
| | - B N M van Berckel
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, the Netherlands
| | - C B L M Majoie
- Department of Radiology, Academic Medical Center, Amsterdam, the Netherlands
| | - J Booij
- Department of Nuclear Medicine, Academic Medical Center, Amsterdam, the Netherlands
| | - M J P van Osch
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - E T van Bavel
- Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, the Netherlands
| | - R Boellaard
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, the Netherlands
| | - A A Lammertsma
- Department of Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, the Netherlands
| | - A J Nederveen
- Department of Radiology, Academic Medical Center, Amsterdam, the Netherlands
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Smoking normalizes cerebral blood flow and oxygen consumption after 12-hour abstention. J Cereb Blood Flow Metab 2015; 35:699-705. [PMID: 25605288 PMCID: PMC4420887 DOI: 10.1038/jcbfm.2014.246] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/12/2014] [Accepted: 12/05/2014] [Indexed: 02/07/2023]
Abstract
Acute nicotine administration stimulates [(14)C]deoxyglucose trapping in thalamus and other regions of rat brain, but acute effects of nicotine and smoking on energy metabolism have rarely been investigated in human brain by positron emission tomography (PET). We obtained quantitative PET measurements of cerebral blood flow (CBF) and metabolic rate of oxygen (CMRO2) in 12 smokers who had refrained from smoking overnight, and in a historical group of nonsmokers, testing the prediction that overnight abstinence results in widespread, coupled reductions of CBF and CMRO2. At the end of the abstention period, global grey-matter CBF and CMRO2 were both reduced by 17% relative to nonsmokers. At 15 minutes after renewed smoking, global CBF had increased insignificantly, while global CMRO2 had increased by 11%. Regional analysis showed that CMRO2 had increased in the left putamen and thalamus, and in right posterior cortical regions at this time. At 60 and 105 minutes after smoking resumption, CBF had increased by 8% and CMRO2 had increased by 11-12%. Thus, we find substantial and global impairment of CBF/CMRO2 in abstaining smokers, and acute restoration by resumption of smoking. The reduced CBF and CMRO2 during acute abstention may mediate the cognitive changes described in chronic smokers.
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27
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Iida H, Iguchi S, Teramoto N, Koshino K, Zeniya T, Yamamoto A, Kudomi N, Moriguchi T, Hori Y, Enmi J, Kawashima H, Joni Shah N, Nakagawara J. Adequacy of a compartment model for CMRO₂ quantitation using ¹⁵O-labeled oxygen and PET: a clearance measurement of ¹⁵O-radioactivity following intracarotid bolus injection of ¹⁵O-labeled oxyhemoglobin on Macaca fascicularis. J Cereb Blood Flow Metab 2014; 34:1434-9. [PMID: 25005879 PMCID: PMC4158673 DOI: 10.1038/jcbfm.2014.118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 06/04/2014] [Accepted: 06/04/2014] [Indexed: 11/21/2022]
Abstract
We aimed at evaluating the adequacy of the commonly employed compartmental model for quantitation of cerebral metabolic rate of oxygen (CMRO2) using (15)O-labeled oxygen ((15)O2) and positron emission tomography (PET). Sequential PET imaging was carried out on monkeys following slow bolus injection of blood samples containing (15)O2-oxyhemoglobin ((15)O2-Hb), (15)O-labeled water (H2(15)O), and C(15)O-labeled hemoglobin (C(15)O-Hb) into the internal carotid artery (ICA). Clearance slopes were assessed in the middle cerebral artery territory of the injected hemisphere. The time-activity curves were bi-exponential for both (15)O2-Hb and H2(15)O. Single exponential fitting to the early (5 to 40 seconds) and late (80 to 240 seconds) periods after the peak was performed and the (15)O2-Hb and H2(15)O results were compared. It was found that a significant difference between the clearance rates of the (15)O2-Hb and H2(15)O injections is unlikely, which supports the mathematical model that is widely used to describe the kinetics of (15)O2-Hb and H2(15)O in cerebral tissues and is the basis of recent approaches to simultaneously assess CMRO2 and cerebral blood flow in a single PET session. However, it should be noted that more data are necessary to unequivocally confirm the result.
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Affiliation(s)
- Hidehiro Iida
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan
| | - Satoshi Iguchi
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan
| | - Noboru Teramoto
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan
| | - Kazuhiro Koshino
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan
| | - Tsutomu Zeniya
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan
| | - Akihide Yamamoto
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan
| | - Nobuyuki Kudomi
- 1] Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan [2] Department of Medical Physics, Faculty of Medicine, Kagawa University, Kitagun, Kagawa, Japan
| | - Tetsuaki Moriguchi
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan
| | - Yuki Hori
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan
| | - Junichiro Enmi
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan
| | - Hidekazu Kawashima
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan
| | - Nadim Joni Shah
- Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Jyoji Nakagawara
- Integrative Stroke Imaging Center, Department of Neurosurgery, National Cerebral and Cardiovascular Center, Suit City, Osaka, Japan
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Uchino K, Lin R, Zaidi SF, Kuwabara H, Sashin D, Bircher N, Chang YF, Hammer MD, Reddy V, Jovin TG, Vora N, Jumaa M, Massaro L, Billigen J, Boada F, Yonas H, Nemoto EM. Increased cerebral oxygen metabolism and ischemic stress in subjects with metabolic syndrome-associated risk factors: preliminary observations. Transl Stroke Res 2013; 1:178-83. [PMID: 22034586 DOI: 10.1007/s12975-010-0028-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hypertension, diabetes, obesity, and dyslipidemia are risk factors that characterize metabolic syndrome (MetS), which increases the risk for stroke by 40%. In a preliminary study, our aim was to evaluate cerebrovascular reactivity and oxygen metabolism in subjects free of vascular disease but with one or more of these risk factors. Volunteers (n=15) 59±15 (mean±SD)years of age clear of cerebrovascular disease by magnetic resonance angiography but with one or more risk factors were studied by quantitative positron emission tomography for measure ment of cerebral blood flow, oxygen consumption, oxygen extraction fraction (OEF), and acetazolamide cerebrovascular reactivity. Eight of ten subjects with MetS risk factors had OEF >50%. None of the five without risk factors had OEF >50%. The presence of MetS risk factors was highly correlated with OEF >50% by Fisher's exact test (p<0.007). The increase in OEF was significantly (P<0.001) correlated with cerebral metabolic rate for oxygen. Increased OEF was not associated with compromised acetazolamide cerebrovascular reactivity. Subjects with one or more MetS risk factors are characterized by increased cerebral oxygen consumption and ischemic stress, which may be related to increased risk of cerebrovascular disease and stroke.
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Affiliation(s)
- Ken Uchino
- Cerebrovascular Center, Cleveland Clinic, Cleveland, OH, USA
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Rodell A, Aanerud J, Braendgaard H, Gjedde A. Washout allometric reference method (WARM) for parametric analysis of [(11)C]PIB in human brains. Front Aging Neurosci 2013; 5:45. [PMID: 24348416 PMCID: PMC3842163 DOI: 10.3389/fnagi.2013.00045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 11/07/2013] [Indexed: 01/28/2023] Open
Abstract
Rapid clearance and disappearance of a tracer from the circulation challenges the determination of the tracer's binding potentials in brain (BPND) by positron emission tomography (PET). This is the case for the analysis of the binding of radiolabeled [11C]Pittsburgh Compound B ([11C]PIB) to amyloid-β (Aβ) plaques in brain of patients with Alzheimer's disease (AD). To resolve the issue of rapid clearance from the circulation, we here introduce the flow-independent Washout Allometric Reference Method (WARM) for the analysis of washout and binding of [11C]PIB in two groups of human subjects, healthy aged control subjects (HC), and patients suffering from AD, and we compare the results to the outcome of two conventional analysis methods. We also use the rapid initial clearance to obtain a surrogate measure of the rate of cerebral blood flow (CBF), as well as a method of identifying a suitable reference region directly from the [11C]PIB signal. The difference of average absolute CBF values between the AD and HC groups was highly significant (P < 0.003). The CBF measures were not significantly different between the groups when normalized to cerebellar gray matter flow. Thus, when flow differences confound conventional measures of [11C]PIB binding, the separate estimates of CBF and BPND provide additional information about possible AD. The results demonstrate the importance of data-driven estimation of CBF and BPND, as well as reference region detection from the [11C]PIB signal. We conclude that the WARM method yields stable measures of BPND with relative ease, using only integration for noise reduction and no model regression. The method accounts for relative flow differences in the brain tissue and yields a calibrated measure of absolute CBF directly from the [11C]PIB signal. Compared to conventional methods, WARM optimizes the Aβ plaque load discrimination between patients with AD and healthy controls (P = 0.009).
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Affiliation(s)
- Anders Rodell
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital Aarhus, Denmark
| | - Joel Aanerud
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital Aarhus, Denmark
| | - Hans Braendgaard
- Department of Neurology, Aarhus University Hospital Aarhus, Denmark
| | - Albert Gjedde
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital Aarhus, Denmark ; Department of Neuroscience and Pharmacology, University of Copenhagen Copenhagen, Denmark
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Gjedde A, Aanerud J, Braendgaard H, Rodell AB. Blood-brain transfer of Pittsburgh compound B in humans. Front Aging Neurosci 2013; 5:70. [PMID: 24223554 PMCID: PMC3819578 DOI: 10.3389/fnagi.2013.00070] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 10/19/2013] [Indexed: 11/13/2022] Open
Abstract
In the labeled form, the Pittsburgh compound B (2-(4′-{N-methyl-[11C]}methyl-aminophenyl)-6-hydroxy-benzothiazole, [11C]PiB), is used as a biomarker for positron emission tomography (PET) of brain β-amyloid deposition in Alzheimer's disease (AD). The permeability of [11C]PiB in the blood-brain barrier is held to be high but the permeability-surface area product and extraction fractions in patients or healthy volunteers are not known. We used PET to determine the clearance associated with the unidrectional blood-brain transfer of [11C]PiB and the corresponding cerebral blood flow rates in frontal lobe, whole cerebral cortex, and cerebellum of patients with Alzheimer's disease and healthy volunteers. Regional cerebral blood flow rates differed significantly between the two groups. Thus, regional and whole-brain permeability-surface area products were identical, in agreement with the observation that numerically, but insignificantly, unidirectional blood-brain clearances are lower and extraction fractions higher in the patients. The evidence of unchanged permeability-surface area products in the patients implies that blood flow changes can be deduced from the unidirectional blood-brain clearances of [11C]PiB in the patients.
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Affiliation(s)
- Albert Gjedde
- Department of Neuroscience and Pharmacology, University of Copenhagen Copenhagen, Denmark ; Department of Nuclear Medicine and PET Centre, Aarhus University Hospital Aarhus, Denmark ; Center of Functionally Integrative Neuroscience, Faculty of Health, Aarhus University Aarhus, Denmark ; Department of Neurology, McGill University Montreal, QC, Canada ; Department of Radiology and Radiological Science, Johns Hopkins University Baltimore, MD, USA
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Brain metabolism in patients with hepatic encephalopathy studied by PET and MR. Arch Biochem Biophys 2013; 536:131-42. [PMID: 23726863 DOI: 10.1016/j.abb.2013.05.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 05/07/2013] [Accepted: 05/13/2013] [Indexed: 01/15/2023]
Abstract
We review PET- and MR studies on hepatic encephalopathy (HE) metabolism in human subjects from the point of views of methods, methodological assumptions and use in studies of cirrhotic patients with clinically overt HE, cirrhotic patients with minimal HE, cirrhotic patients with no history of HE and healthy subjects. Key results are: (1) Cerebral oxygen uptake and blood flow are reduced to 2/3 in cirrhotic patients with clinically overt HE but not in cirrhotic patients with minimal HE or no HE compared to healthy subjects. (2) Cerebral ammonia metabolism is enhanced due to increased blood ammonia in cirrhotic patients but the kinetics of cerebral ammonia uptake and metabolism is not affected by hyperammonemia. (3) Recent advantages in MR demonstrate low-grade cerebral oedema not only in astrocytes but also in the white matter in cirrhotic patients with HE.
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Noninvasive estimation of the arterial input function in positron emission tomography imaging of cerebral blood flow. J Cereb Blood Flow Metab 2013; 33:115-21. [PMID: 23072748 PMCID: PMC3597366 DOI: 10.1038/jcbfm.2012.143] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Positron emission tomography (PET) with (15)O-labeled water can provide reliable measurement of cerebral blood flow (CBF). Quantification of CBF requires knowledge of the arterial input function (AIF), which is usually provided by arterial blood sampling. However, arterial sampling is invasive. Moreover, the blood generally is sampled at the wrist, which does not perfectly represent the AIF of the brain, because of the effects of delay and dispersion. We developed and validated a new noninvasive method to obtain the AIF directly by PET imaging of the internal carotid artery in a region of interest (ROI) defined by coregistered high-resolution magnetic resonance angiography. An ROI centered at the petrous portion of the internal carotid artery was defined, and the AIF was estimated simultaneously with whole brain blood flow. The image-derived AIF (IDAIF) method was validated against conventional arterial sampling. The IDAIF generated highly reproducible CBF estimations, generally in good agreement with the conventional technique.
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Oxygen consumption and blood flow coupling in human motor cortex during intense finger tapping: implication for a role of lactate. J Cereb Blood Flow Metab 2012; 32:1859-68. [PMID: 22781333 PMCID: PMC3463880 DOI: 10.1038/jcbfm.2012.89] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Rates of cerebral blood flow (CBF) and glucose consumption (CMR(glc)) rise in cerebral cortex during continuous stimulation, while the oxygen-glucose index (OGI) declines as an index of mismatched coupling of oxygen consumption (cerebral metabolic rate of oxygen-CMRO(2)) to CBF and CMR(glc). To test whether the mismatch reflects a specific role of aerobic glycolysis during functional brain activation, we determined CBF and CMRO(2) with positron emission tomography (PET) when 12 healthy volunteers executed finger-to-thumb apposition of the right hand. Movements began 1, 10, or 20 minutes before administration of the radiotracers. In primary and supplementary motor cortices and cerebellum, CBF had increased at 1 minute of exercise and remained elevated for the duration of the 20-minute session. In contrast, the CMRO(2) numerically had increased insignificantly in left M1 and supplementary motor area at 1 minute, but had declined significantly at 10 minutes, returning to baseline at 20 minutes. As measures of CMR(glc) are impossible during short-term activations, we used measurements of CBF as indices of CMR(glc). The decline of CMRO(2) at 10 minutes paralleled a calculated decrease of OGI at this time. The implied generation of lactate in the tissue suggested an important hypothetical role of the metabolite as regulator of CBF during activation.
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Rodell AB, Aanerud J, Braendgaard H, Gjedde A. Low Residual CBF Variability in Alzheimer's Disease after Correction for CO(2) Effect. FRONTIERS IN NEUROENERGETICS 2012; 4:8. [PMID: 22783187 PMCID: PMC3389721 DOI: 10.3389/fnene.2012.00008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 06/04/2012] [Indexed: 11/13/2022]
Abstract
We tested the claim that inter-individual CBF variability in Alzheimer's disease (AD) is substantially reduced after correction for arterial carbon dioxide tension (PaCO(2)). Specifically, we tested whether the variability of CBF in brain of patients with AD differed significantly from brain of age-matched healthy control subjects (HC). To eliminate the CO(2)-induced variability, we developed a novel and generally applicable approach to the correction of CBF for changes of PaCO(2) and applied the method to positron emission tomographic (PET) measures of CBF in AD and HC groups of subjects. After correction for the differences of CO(2) tension, the patients with AD lost the inter-individual CBF variability that continued to characterize the HC subjects. The difference (ΔK(1)) between the blood-brain clearances (K(1)) of water (the current measure of CBF) and oxygen (the current measure of oxygen clearance) was reduced globally in AD and particularly in the parietal, occipital, and temporal lobes. We then showed that oxygen gradients calculated for brain tissue were similar in AD and HC, indicating that the low residual variability of CBF in AD may be due to low functional demands for oxidative metabolism of brain tissue rather than impaired delivery of oxygen.
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Affiliation(s)
- Anders Bertil Rodell
- Department of Nuclear Medicine and Positron Emission Tomography Centre, Aarhus University HospitalAarhus, Denmark
| | - Joel Aanerud
- Department of Nuclear Medicine and Positron Emission Tomography Centre, Aarhus University HospitalAarhus, Denmark
| | - Hans Braendgaard
- Department of Neurology, Aarhus University HospitalAarhus, Denmark
| | - Albert Gjedde
- Department of Nuclear Medicine and Positron Emission Tomography Centre, Aarhus University HospitalAarhus, Denmark
- Department of Neuroscience and Pharmacology and Center of Healthy Aging, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagen, Denmark
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Aanerud J, Borghammer P, Chakravarty MM, Vang K, Rodell AB, Jónsdottir KY, Møller A, Ashkanian M, Vafaee MS, Iversen P, Johannsen P, Gjedde A. Brain energy metabolism and blood flow differences in healthy aging. J Cereb Blood Flow Metab 2012; 32:1177-87. [PMID: 22373642 PMCID: PMC3390816 DOI: 10.1038/jcbfm.2012.18] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cerebral metabolic rate of oxygen consumption (CMRO(2)), cerebral blood flow (CBF), and oxygen extraction fraction (OEF) are important indices of healthy aging of the brain. Although a frequent topic of study, changes of CBF and CMRO(2) during normal aging are still controversial, as some authors find decreases of both CBF and CMRO(2) but increased OEF, while others find no change, and yet other find divergent changes. In this reanalysis of previously published results from positron emission tomography of healthy volunteers, we determined CMRO(2) and CBF in 66 healthy volunteers aged 21 to 81 years. The magnitudes of CMRO(2) and CBF declined in large parts of the cerebral cortex, including association areas, but the primary motor and sensory areas were relatively spared. We found significant increases of OEF in frontal and parietal cortices, excluding primary motor and somatosensory regions, and in the temporal cortex. Because of the inverse relation between OEF and capillary oxygen tension, increased OEF can compromise oxygen delivery to neurons, with possible perturbation of energy turnover. The results establish a possible mechanism of progression from healthy to unhealthy brain aging, as the regions most affected by age are the areas that are most vulnerable to neurodegeneration.
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Affiliation(s)
- Joel Aanerud
- Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark
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Szilágyi G, Vas A, Kerényi L, Nagy Z, Csiba L, Gulyás B. Correlation between crossed cerebellar diaschisis and clinical neurological scales. Acta Neurol Scand 2012; 125:373-81. [PMID: 21781057 DOI: 10.1111/j.1600-0404.2011.01576.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND A common consequence of unilateral stroke is crossed cerebellar diaschisis (CCD), a decrease in regional blood flow (CBF) and metabolism (CMRglu) in the cerebellar hemisphere contralateral to the affected cerebral hemisphere. Former studies indicated a post-stroke time-dependent relationship between the degree of CCD and the clinical status of acute and sub-acute stroke patients, but no study has been performed in post-stroke patients. OBJECTIVES The objective of this investigation was to evaluate the quantitative correlation between the degree of CCD and the values of clinical stroke scales in post-stroke patients. MATERIALS AND METHODS We measured with positron emission tomography (PET) regional CBF and CMRglu values in the affected cortical regions and the contralateral cerebellum in ten ischaemic post-stroke patients. Based on these quantitative parameters, the degree of diaschisis (DoD) was calculated, and the DoD values were correlated with three clinical stroke scales [Barthel Index, Orgogozo Scale and Scandinavian Neurological Scale (SNS)]. RESULTS There were significant linear correlations between all clinical stroke scales and the CCD values (Barthel Index and Orgogozo Scale: P < 0.001, for both CBF and CMRglu; SNS: P = 0.007 and P = 0.044; CBF and CMRglu, respectively). CONCLUSIONS The findings indicate that DoD can be used as a quantitative indicator of the functional impairments following stroke, i.e. it can serve as a potential surrogate of the severity of the damage.
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Affiliation(s)
- G Szilágyi
- Department of Neurology, State Health Center, Budapest, Hungary
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Abstract
To develop a less-stressful and simple method for measurement of the cerebral metabolic rate of oxygen (CMRO(2)) in small animals, the steady-state method was applied to injectable (15)O(2)-PET ((15)O(2)-positron emission tomography) using hemoglobin-containing vesicles ((15)O(2)-HbV). Ten normal rats and 10 with middle cerebral arterial occlusion (MCAO) were studied using a small animal PET scanner. A series of (15)O-PET scans with C(15)O-labeled HbV, H(2)(15)O, and (15)O(2)-HbV were performed with 10 to 15 minutes intervals to measure cerebral blood volume (CBV), cerebral blood flow (CBF), and CMRO(2). Positron emission tomography scans were started with a tracer injection using a multiprogramming syringe pump, which provides a slowly increasing injection volume to achieve steady-state radioactivity for H(2)(15)O and (15)O(2)-HbV scans. The radioactivity concentration of (15)O rapidly achieved equilibrium in the blood and whole brain at about 2 minutes after H(2)(15)O and (15)O(2)-HbV administration, which was stable during the scans. The whole brain mean values of CBF, CBV, and CMRO(2) were 54.3±2.0 mL per 100 g per minute, 4.9±0.4 mL/100 g, and 2.8±0.2 μmoL per g per minute (6.2±0.4 mL per 100 g per minute) in the normal rats, respectively. In the MCAO model rats, all hemodynamic parameters of the infarction area on the occlusion side significantly decreased. The steady-state method with (15)O-labeled HbV is simple and useful to analyze hemodynamic changes in studies with model animals.
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Borghammer P, Cumming P, Østergaard K, Gjedde A, Rodell A, Bailey CJ, Vafaee MS. Cerebral oxygen metabolism in patients with early Parkinson's disease. J Neurol Sci 2011; 313:123-8. [PMID: 21975016 DOI: 10.1016/j.jns.2011.09.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 08/02/2011] [Accepted: 09/08/2011] [Indexed: 10/17/2022]
Abstract
AIM Decreased activity of the mitochondrial electron transport chain (ETC) has been implicated in the pathogenesis of Parkinson's disease (PD). This model would most likely predict a decrease in the rate of cerebral oxygen consumption (CMRO(2)). To test this hypothesis, we compared CMRO(2) and cerebral blood flow (CBF) PET scans from PD patients and healthy controls. MATERIALS AND METHODS Nine early-stage PD patients and 15 healthy age-matched controls underwent PET scans for quantitative mapping of CMRO(2) and CBF. Between-group differences were evaluated for absolute data and intensity-normalized values. RESULTS No group differences were detected in regional magnitudes of CMRO(2) or CBF. Upon normalization using the reference cluster method, significant relative CMRO(2) decreases were evident in widespread prefrontal, parieto-occipital, and lateral temporal regions. Sensory-motor and subcortical regions, brainstem, and the cerebellum were spared. A similar pattern was evident in normalized CBF data, as described previously. CONCLUSION While the data did not reveal substantially altered absolute CMRO(2) in brain of PD patients, employing data-driven intensity normalization revealed widespread relative CMRO(2) decreases in cerebral cortex. The detected pattern was very similar to that reported in earlier CBF and CMRglc studies of PD, and in the CBF images from the same subjects. Thus, the present results are consistent with the occurrence of parallel declines in CMRO(2), CBF, and CMRglc in spatially contiguous cortical regions in early PD, and support the hypothesis that ETC dysfunction could be a primary pathogenic mechanism in early PD.
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Affiliation(s)
- Per Borghammer
- Deparment of Nuclear Medicine, Aarhus University Hospital, Denmark.
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McNeil JD, Propper B, Walker J, Holguin L, Evans L, Lee K, Fox PT, Michalek JE, Baisden CE. A bovine hemoglobin-based oxygen carrier as pump prime for cardiopulmonary bypass: reduced systemic lactic acidosis and improved cerebral oxygen metabolism during low flow in a porcine model. J Thorac Cardiovasc Surg 2011; 142:411-7. [PMID: 21641005 DOI: 10.1016/j.jtcvs.2010.11.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Revised: 10/19/2010] [Accepted: 11/05/2010] [Indexed: 10/18/2022]
Abstract
OBJECTIVES Cerebral ischemia can occur during cardiopulmonary bypass, especially during low flow. HBOC-201 (OPK Biotech, Cambridge, Mass) is a hemoglobin-based oxygen-carrying solution that enhances oxygen delivery. This project evaluated the benefits on total body and cerebral oxygen delivery and consumption using HBOC-201 during cardiopulmonary bypass. METHODS Twelve immature swine were assigned to one of 2 groups. One group used HBOC-201 in pump prime, and the other used donor porcine blood. Cardiopulmonary bypass was initiated and then flow was serially decreased from 100% to 75%, to 50%, and then back to full flow. At each interval, (15)O positron emission tomographic analysis was performed, and blood was collected. Total body and cerebral oxygen delivery and consumption were calculated. Statistical analysis was performed with a Tukey-Kramer adjusted P value based on a repeated measures linear model on log-transformed data. RESULTS Total and plasma hemoglobin levels were higher in the HBOC-201 group. Oxygen delivery and consumption were not statistically different but did tend to be higher in the HBOC-201 group. Mixed venous saturation was lower in the HBOC-201 group but not significant. Mild metabolic acidosis with increased lactate levels developed in the blood group. Mean cerebral blood flow decreased in both groups when total flow was 50%. In the HBOC-201 group cerebral oxygen metabolism was maintained. CONCLUSIONS The addition of HBOC-201 for cardiopulmonary bypass appears to improve oxygen use and minimize anaerobic metabolism. Cerebral oxygen use was preserved in the HBOC-201 group, even during decrease in blood flow. These findings support the reported improved oxygen-unloading properties of HBOC-201 and might provide a benefit during cardiopulmonary bypass.
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Affiliation(s)
- Jeffrey D McNeil
- Department of Surgery, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
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Xie G, Deschamps A, Backman S, Fiset P, Chartrand D, Dagher A, Plourde G. Critical involvement of the thalamus and precuneus during restoration of consciousness with physostigmine in humans during propofol anaesthesia: a positron emission tomography study. Br J Anaesth 2011; 106:548-57. [DOI: 10.1093/bja/aeq415] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Cerebral blood flow measurement using fMRI and PET: a cross-validation study. Int J Biomed Imaging 2010; 2008:516359. [PMID: 18825270 PMCID: PMC2553188 DOI: 10.1155/2008/516359] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Accepted: 07/22/2008] [Indexed: 11/28/2022] Open
Abstract
An important aspect of functional magnetic resonance imaging (fMRI) is the study of brain hemodynamics, and MR arterial spin labeling (ASL) perfusion imaging has gained wide acceptance as a robust and noninvasive technique. However, the cerebral blood flow (CBF) measurements obtained with ASL fMRI have not been fully validated, particularly during global CBF modulations. We present a comparison of cerebral blood flow changes (ΔCBF) measured using a flow-sensitive alternating inversion recovery (FAIR) ASL perfusion method to those obtained using H215O PET, which is the current gold standard for in vivo imaging of CBF. To study regional and global CBF changes, a group of 10 healthy volunteers were imaged under identical experimental conditions during presentation of 5 levels of visual stimulation and one level of hypercapnia. The CBF changes were compared using 3 types of region-of-interest (ROI) masks. FAIR measurements of CBF changes were found to be slightly lower than those measured with PET (average ΔCBF of 21.5 ± 8.2% for FAIR versus 28.2 ± 12.8% for PET at maximum stimulation intensity). Nonetheless, there was a strong correlation between measurements of the two modalities. Finally, a t-test comparison of the slopes of the linear fits of PET versus ASL ΔCBF for all 3 ROI types indicated no significant difference from unity (P > .05).
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Gjedde A, Keiding S, Vilstrup H, Iversen P. No oxygen delivery limitation in hepatic encephalopathy. Metab Brain Dis 2010; 25:57-63. [PMID: 20182779 DOI: 10.1007/s11011-010-9179-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 01/28/2010] [Indexed: 10/19/2022]
Abstract
Hepatic encephalopathy is a condition of reduced brain functioning in which both blood flow and brain energy metabolism declined. It is not known whether blood flow or metabolism is the primary limiting factor of brain function in this condition. We used calculations of mitochondrial oxygen tension to choose between cause and effect in three groups of volunteers, including healthy control subjects (HC), patients with cirrhosis of the liver without hepatic encephalopathy (CL), and patients with cirrhosis with acute hepatic encephalopathy. Compared to HC subjects, blood flow and energy metabolism had declined in all gray matter regions of the brain in patients with HE but not significantly in patients with CL. Analysis of flow-metabolism coupling indicated that blood flow declined in HE as a consequence of reduced brain energy metabolism implied by the calculation of increased mitochondrial oxygen tensions that patients with HE were unable to utilize. We ascribe the inability to use the delivered oxygen of patients with HE to a specific inhibition associated with oxidative metabolism in mitochondria.
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Affiliation(s)
- Albert Gjedde
- Pathophysiology and Experimental Tomography Center, Aarhus Hospital, Aarhus University Hospitals, Aarhus, Denmark.
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Carbogen inhalation increases oxygen transport to hypoperfused brain tissue in patients with occlusive carotid artery disease. Brain Res 2009; 1304:90-5. [DOI: 10.1016/j.brainres.2009.09.076] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 09/16/2009] [Accepted: 09/18/2009] [Indexed: 11/19/2022]
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Lüdemann L, Sreenivasa G, Amthauer H, Michel R, Gellermann J, Wust P. Use of H215O-PET for investigating perfusion changes in pelvic tumors due to regional hyperthermia. Int J Hyperthermia 2009; 25:299-308. [DOI: 10.1080/02656730902744395] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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45
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Abstract
We reviewed the literature on human cerebral circulation and oxygen metabolism, as measured by positron emission tomography (PET), with respect to normal values and of regulation of cerebral circulation. A multicenter study in Japan showed that between-center variations in cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) values were not considerably larger than the corresponding within-center variations. Overall mean +/- SD values in cerebral cortical regions of normal human subjects were as follows: CBF = 44.4 +/- 6.5 ml/100 ml/min; CBV = 3.8 +/- 0.7 ml/100 ml; OEF = 0.44 +/- 0.06; CMRO2 = 3.3 +/- 0.5 ml/100 ml/min (11 PET centers, 70 subjects). Intrinsic regulation of cerebral circulation involves several factors. Autoregulation maintains CBF in response to changes in cerebral perfusion pressure; chemical factors such as PaCO2 affect cerebral vascular tone and alter CBF; changes in neural activity cause changes in cerebral energy metabolism and CBF; neurogenic control of CBF occurs by sympathetic innervation. Regional differences in vascular response to changes in PaCO2 have been reported, indicating regional differences in cerebral vascular tone. Relations between CBF and CBV during changes in PaCO2 and during changes in neural activity were in good agreement with Poiseuille's law. The mechanisms of vascular response to neural activation and deactivation were independent on those of responses to PaCO2 changes. CBV in a brain region is the sum of three components: arterial, capillary and venous blood volumes. It has been reported that the arterial blood volume fraction is approximately 30% in humans and that changes in human CBV during changes in PaCO2 are caused by changes in arterial blood volume without changes in venous blood volume. These findings should be considered in future studies of the pathophysiology of cerebrovascular diseases.
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Affiliation(s)
- Hiroshi Ito
- Department of Nuclear Medicine and Radiology, Division of Brain Sciences, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
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Okazawa H, Kudo T. Clinical impact of hemodynamic parameter measurement for cerebrovascular disease using positron emission tomography and 15O-labeled tracers. Ann Nucl Med 2009; 23:217-27. [PMID: 19353235 DOI: 10.1007/s12149-009-0235-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Accepted: 11/17/2008] [Indexed: 10/20/2022]
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Artefactual subcortical hyperperfusion in PET studies normalized to global mean: Lessons from Parkinson’s disease. Neuroimage 2009; 45:249-57. [DOI: 10.1016/j.neuroimage.2008.07.042] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2008] [Revised: 07/15/2008] [Accepted: 07/20/2008] [Indexed: 11/21/2022] Open
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Xie CH, Kong KM, Guan JT, Chen YX, He JK, Qi WL, Wang XJ, Shen ZW, Wu RH. SSFSE sequence functional MRI of the human cervical spinal cord with complex finger tapping. Eur J Radiol 2009; 70:1-6. [PMID: 18353589 DOI: 10.1016/j.ejrad.2008.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Revised: 10/05/2007] [Accepted: 01/10/2008] [Indexed: 02/05/2023]
Abstract
PURPOSE Functional MR imaging of the human cervical spinal cord was carried out on volunteers during alternated rest and a complex finger tapping task, in order to detect image intensity changes arising from neuronal activity. METHODS Functional MR imaging data using single-shot fast spin-echo sequence (SSFSE) with echo time 42.4 ms on a 1.5 T GE Clinical System were acquired in eight subjects performing a complex finger tapping task. Cervical spinal cord activation was measured both in the sagittal and transverse imaging planes. Postprocessing was performed by AFNI (Analysis of Functional Neuroimages) software system. RESULTS Intensity changes (5.5-7.6%) were correlated with the time course of stimulation and were consistently detected in both sagittal and transverse imaging planes of the cervical spinal cord. The activated regions localized to the ipsilateral side of the spinal cord in agreement with the neural anatomy. CONCLUSION Functional MR imaging signals can be reliably detected with finger tapping activity in the human cervical spinal cord using a SSFSE sequence with 42.4 ms echo time. The anatomic location of neural activity correlates with the muscles used in the finger tapping task.
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Affiliation(s)
- Chu-hai Xie
- Department of Orthopedic Surgery, The Second Affiliated Hospital to Shantou University Medical College, Shantou, Guangdong 515041, China.
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Data-driven intensity normalization of PET group comparison studies is superior to global mean normalization. Neuroimage 2009; 46:981-8. [PMID: 19303935 DOI: 10.1016/j.neuroimage.2009.03.021] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 02/13/2009] [Accepted: 03/10/2009] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Global mean (GM) normalization is one of the most commonly used methods of normalization in PET and SPECT group comparison studies of neurodegenerative disorders. It requires that no between-group GM difference is present, which may be strongly violated in neurodegenerative disorders. Importantly, such GM differences often elude detection due to the large intrinsic variance in absolute values of cerebral blood flow or glucose consumption. Alternative methods of normalization are needed for this type of data. MATERIALS AND METHODS Two types of simulation were performed using CBF images from 49 controls. Two homogeneous groups of 20 subjects were sampled repeatedly. In one group, cortical CBF was artificially decreased moderately (simulation I) or slightly (simulation II). The other group served as controls. Ratio normalization was performed using five reference regions: (1) Global mean; (2) An unbiased VOI; (3) Data-driven region extraction (Andersson); (4-5) Reference cluster methods (Yakushev et al.). Using voxel-based statistics, it was determined how much of the original signal was detected following each type of normalization. RESULTS For both simulations, global mean normalization performed poorly, with only a few percent of the original signal recovered. Global mean normalization moreover created artificial increases. In contrast, the data-driven reference cluster method detected 65-95% of the original signal. CONCLUSION In the present simulation, the reference cluster method was superior to GM normalization. We conclude that the reference cluster method will likely yield more accurate results in the study of patients with early to moderate stage neurodegenerative disorders.
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Iversen P, Sørensen M, Bak LK, Waagepetersen HS, Vafaee MS, Borghammer P, Mouridsen K, Jensen SB, Vilstrup H, Schousboe A, Ott P, Gjedde A, Keiding S. Low cerebral oxygen consumption and blood flow in patients with cirrhosis and an acute episode of hepatic encephalopathy. Gastroenterology 2009; 136:863-71. [PMID: 19041869 DOI: 10.1053/j.gastro.2008.10.057] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Revised: 09/30/2008] [Accepted: 10/23/2008] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS It is unclear whether patients with hepatic encephalopathy (HE) have disturbed brain oxygen metabolism and blood flow. METHODS We measured cerebral oxygen metabolism rate (CMRO(2)) by using (15)O-oxygen positron emission tomography (PET); and cerebral blood flow (CBF) by using (15)O-water PET in 6 patients with liver cirrhosis and an acute episode of overt HE, 6 cirrhotic patients without HE, and 7 healthy subjects. RESULTS Neither whole-brain CMRO(2) nor CBF differed significantly between cirrhotic patients without HE and healthy subjects, but were both significantly reduced in cirrhotic patients with HE (P < .01). CMRO(2) was 0.96 +/- 0.07 mumol oxygen/mL brain tissue/min (mean +/- SEM) in cirrhotic patients with HE, 1.34 +/- 0.08 in cirrhotic patients without HE, and 1.35 +/- 0.05 in healthy subjects; and CBF was 0.29 +/- 0.01 mL blood/mL brain tissue/min in patients with HE, 0.47 +/- 0.02 in patients without HE, and 0.49 +/- 0.03 in healthy subjects. CMRO(2) and CBF were correlated, and both variables correlated negatively with arterial ammonia concentration. Analysis of regional values, using individual magnetic resonance co-registrations, showed that the reductions in CMRO(2) and CBF in patients with HE were essentially generalized throughout the brain. CONCLUSIONS The observations imply that reduced cerebral oxygen consumption and blood flow in cirrhotic patients with an acute episode of overt HE are associated with HE and not cirrhosis as such, and that the primary event in the pathogenesis of HE could be inhibition of cerebral energy metabolism by increased blood ammonia.
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Affiliation(s)
- Peter Iversen
- PET Centre, Aarhus University Hospital, Aarhus, Denmark
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