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Zoelch N, Heimer J, Richter H, Luechinger R, Archibald J, Thali MJ, Gascho D. In situ temperature determination using magnetic resonance spectroscopy thermometry for noninvasive postmortem examinations. NMR IN BIOMEDICINE 2024:e5171. [PMID: 38757603 DOI: 10.1002/nbm.5171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/28/2024] [Accepted: 04/18/2024] [Indexed: 05/18/2024]
Abstract
Magnetic resonance spectroscopy (MRS) thermometry offers a noninvasive, localized method for estimating temperature by leveraging the temperature-dependent chemical shift of water relative to a temperature-stable reference metabolite under suitable calibration. Consequentially, this technique has significant potential as a tool for postmortem MR examinations in forensic medicine and pathology. In these examinations, the deceased are examined at a wide range of body temperatures, and MRS thermometry may be used for the temperature adjustment of magnetic resonance imaging (MRI) protocols or for corrections in the analysis of MRI or MRS data. However, it is not yet clear to what extent postmortem changes may influence temperature estimation with MRS thermometry. In addition, N-acetylaspartate, which is commonly used as an in vivo reference metabolite, is known to decrease with increasing postmortem interval (PMI). This study shows that lactate, which is not only present in significant amounts postmortem but also has a temperature-stable chemical shift, can serve as a suitable reference metabolite for postmortem MRS thermometry. Using lactate, temperature estimation in postmortem brain tissue of severed sheep heads was accurate up to 60 h after death, with a mean absolute error of less than 0.5°C. For this purpose, published calibrations intended for in vivo measurements were used. Although postmortem decomposition resulted in severe metabolic changes, no consistent deviations were observed between measurements with an MR-compatible temperature probe and MRS thermometry with lactate as a reference metabolite. In addition, MRS thermometry was applied to 84 deceased who underwent a MR examination as part of the legal examination. MRS thermometry provided plausible results of brain temperature in comparison with rectal temperature. Even for deceased with a PMI well above 60 h, MRS thermometry still provided reliable readings. The results show a good suitability of MRS thermometry for postmortem examinations in forensic medicine.
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Affiliation(s)
- Niklaus Zoelch
- Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
- Department of Adult Psychiatry and Psychotherapy, Psychiatric University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Jakob Heimer
- Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
| | - Henning Richter
- Clinic of Diagnostic Imaging, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Roger Luechinger
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Jessica Archibald
- Department of Radiology, Weill Cornell Medicine, New York, New York, USA
| | - Michael J Thali
- Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
| | - Dominic Gascho
- Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
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Mueller C, Jordan I, Jones C, Lawson P, Younger JW. Abnormal immune system response in the brain of women with Fibromyalgia after experimental endotoxin challenge. Brain Behav Immun Health 2023; 30:100624. [PMID: 37114015 PMCID: PMC10126845 DOI: 10.1016/j.bbih.2023.100624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 03/13/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Background The pathophysiology of fibromyalgia (FM) is thought to include an overactive immune system, leading to central nervous system sensitization, allodynia, and hyperalgesia. We aimed to test this theory using an experimental immune system activation procedure and neuroimaging with magnetic resonance spectroscopic imaging (MRSI). Methods Twelve women with FM and 13 healthy women (healthy controls; HC) received 0.3 or 0.4 ng/kg endotoxin and underwent MRSI before and after the infusion. Changes in brain levels of choline (CHO), myo-inositol (MI), N-Acetylaspartate (NAA), and MRSI-derived brain temperature were compared between groups and dosage levels using mixed analyses of variance. Results Significant group-by-time interactions in brain temperature were found in the right thalamus. Post-hoc testing revealed that brain temperature increased by 0.55 °C in the right thalamus in FM (t(10) = -3.483, p = 0.006), but not in HCs (p > 0.05). Dose-by-time interactions revealed brain temperature increases in the right insula after 0.4 ng/kg (t(12) = -4.074, p = 0.002), but not after 0.3 ng/kg (p > 0.05). Dose-by-time interactions revealed decreased CHO in the right Rolandic operculum after 0.4 ng/kg endotoxin (t(13) = 3.242, p = 0.006) but not 0.3 ng/kg. In the left paracentral lobule, CHO decreased after 0.3 ng/kg (t(9) = 2.574, p = 0.030) but not 0.4 ng/kg. Dose-by-time interactions affected MI in several brain regions. MI increased after 0.3 ng/kg in the right Rolandic operculum (t(10) = -2.374, p = 0.039), left supplementary motor area (t(9) = -2.303, p = 0.047), and left occipital lobe (t(10) = -3.757, p = 0.004), with no changes after 0.4 ng/kg (p > 0.05). Group-by time interactions revealed decreased NAA in the left Rolandic operculum in FM (t(13) = 2.664, p = 0.019), but not in HCs (p > 0.05). A dose-by-time interaction showed decreased NAA in the left paracentral lobule after 0.3 ng/kg (t(9) = 3.071, p = 0.013) but not after 0.4 ng/kg (p > 0.05). In the combined sample, there was a main effect of time whereby NAA decreased in the left anterior cingulate (F[1,21] = 4.458, p = 0.047) and right parietal lobe (F[1,21] = 5.457, p = 0.029). Conclusion We found temperature increases and NAA decreases in FM that were not seen in HCs, suggesting that FM patients may have abnormal immune responses in the brain. The 0.3 and 0.4 ng/kg had differential effects on brain temperature and metabolites, with neither dose effecting a stronger response overall. There is insufficient evidence provided by the study to determine whether FM involves abnormal central responses to low-level immune challenges.
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Affiliation(s)
- Christina Mueller
- Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
- Corresponding author. CIRC 312, 1719 6th Ave S, Birmingham, AL, 35233, USA.
| | - Indonesia Jordan
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Chloe Jones
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Prentiss Lawson
- Department of Anesthesiology and Perioperative Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jarred W. Younger
- Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
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Sung D, Risk BB, Wang KJ, Allen JW, Fleischer CC. Resting-State Brain Temperature: Dynamic Fluctuations in Brain Temperature and the Brain-Body Temperature Gradient. J Magn Reson Imaging 2023; 57:1222-1228. [PMID: 35904094 PMCID: PMC9884314 DOI: 10.1002/jmri.28376] [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: 04/27/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND While fluctuations in healthy brain temperature have been investigated over time periods of weeks to months, dynamics over shorter time periods are less clear. PURPOSE To identify physiological fluctuations in brain temperature in healthy volunteers over time scales of approximately 1 hour. STUDY TYPE Prospective. SUBJECTS A total of 30 healthy volunteers (15 female; 26 ± 4 years old). SEQUENCE AND FIELD STRENGTH 3 T; T1-weighted magnetization-prepared rapid gradient-echo (MPRAGE) and semi-localized by adiabatic selective refocusing (sLASER) single-voxel spectroscopy. ASSESSMENTS Brain temperature was calculated from the chemical shift difference between N-acetylaspartate and water. To evaluate within-scan repeatability of brain temperature and the brain-body temperature difference, 128 spectral transients were divided into two sets of 64-spectra. Between-scan repeatability was evaluated using two time periods, ~1-1.5 hours apart. STATISTICAL TESTS A hierarchical linear mixed model was used to calculate within-scan and between-scan correlations (Rw and Rb , respectively). Significance was determined at P ≤ .05. Values are reported as the mean ± standard deviation. RESULTS A significant difference in brain temperature was observed between scans (-0.4 °C) but body temperature was stable (P = .59). Brain temperature (37.9 ± 0.7 °C) was higher than body temperature (36.5 ± 0.5 °C) for all but one subject. Within-scan correlation was high for brain temperature (Rw = 0.95) and brain-body temperature differences (Rw = 0.96). Between scans, variability was high for both brain temperature (Rb = 0.30) and brain-body temperature differences (Rb = 0.41). DATA CONCLUSION Significant changes in brain temperature over time scales of ~1 hour were observed. High short-term repeatability suggests temperature changes appear to be due to physiology rather than measurement error. EVIDENCE LEVEL 2 TECHNICAL EFFICACY: Stage 1.
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Affiliation(s)
- Dongsuk Sung
- Department of Radiology and Imaging Sciences, Emory University School of Medicine
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University
| | - Benjamin B. Risk
- Department of Biostatistics and Bioinformatics, Emory University
| | - Kelly J. Wang
- Department of Radiology and Imaging Sciences, Emory University School of Medicine
- Department of Neuroscience, Georgia Institute of Technology
| | - Jason W. Allen
- Department of Radiology and Imaging Sciences, Emory University School of Medicine
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University
| | - Candace C. Fleischer
- Department of Radiology and Imaging Sciences, Emory University School of Medicine
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University
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Effects of orientation-dependent susceptibility on MR chemical shift brain thermometry. Magn Reson Imaging 2023; 95:59-62. [PMID: 36273626 PMCID: PMC9744186 DOI: 10.1016/j.mri.2022.10.007] [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: 06/13/2022] [Revised: 10/06/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022]
Abstract
PURPOSE The presence of orientation-dependent susceptibility artifacts in magnetic resonance chemical shift thermometry (CST) can confound accurate temperature calculations. Here, we quantify the effect of white matter (WM) tract orientation on CST due to tissue-specific susceptibility. METHODS Twenty-nine healthy volunteers (27 ± 4 years old) were scanned on a 3 T MR scanner with a 32-channel head coil. Diffusion tensor imaging (DTI), T1-weighted imaging, and single voxel spectroscopy (SVS) for CST were acquired. Participants were then asked to rotate their head ∼3-5° (yaw or roll) to alter the orientation of WM tracts relative to the external magnetic field. After head rotation, a second SVS scan and T1-weighted imaging were acquired. The WM-fraction-normalized DTI principal eigenvector (V1) images were used to calculate the length of the x-y component of V1, which was used as a surrogate for WM tracts perpendicular to B0. A linear regression model was used to determine the relationship between the perpendicular WM tracts and brain temperature. RESULTS Significant temperature differences between post- and pre-head rotation scans were observed for brain (-0.72 °C ± 1.36 °C, p = 0.01) but not body (0.012 °C ± 0.07 °C, p = 0.37) temperatures. The difference in brain temperature was positively associated with the corresponding change in perpendicular WM tracts after head rotation (R2 = 0.26, p = 0.005). CONCLUSION Our results indicate WM tract orientation affects temperature calculations, suggesting artifacts from orientation-dependent susceptibility may be present in CST.
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Rzechorzek NM, Thrippleton MJ, Chappell FM, Mair G, Ercole A, Cabeleira M, Rhodes J, Marshall I, O'Neill JS. A daily temperature rhythm in the human brain predicts survival after brain injury. Brain 2022; 145:2031-2048. [PMID: 35691613 PMCID: PMC9336587 DOI: 10.1093/brain/awab466] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 11/03/2021] [Accepted: 11/20/2021] [Indexed: 02/06/2023] Open
Abstract
Patients undergo interventions to achieve a 'normal' brain temperature; a parameter that remains undefined for humans. The profound sensitivity of neuronal function to temperature implies the brain should be isothermal, but observations from patients and non-human primates suggest significant spatiotemporal variation. We aimed to determine the clinical relevance of brain temperature in patients by establishing how much it varies in healthy adults. We retrospectively screened data for all patients recruited to the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) High Resolution Intensive Care Unit Sub-Study. Only patients with direct brain temperature measurements and without targeted temperature management were included. To interpret patient analyses, we prospectively recruited 40 healthy adults (20 males, 20 females, 20-40 years) for brain thermometry using magnetic resonance spectroscopy. Participants were scanned in the morning, afternoon, and late evening of a single day. In patients (n = 114), brain temperature ranged from 32.6 to 42.3°C and mean brain temperature (38.5 ± 0.8°C) exceeded body temperature (37.5 ± 0.5°C, P < 0.0001). Of 100 patients eligible for brain temperature rhythm analysis, 25 displayed a daily rhythm, and the brain temperature range decreased in older patients (P = 0.018). In healthy participants, brain temperature ranged from 36.1 to 40.9°C; mean brain temperature (38.5 ± 0.4°C) exceeded oral temperature (36.0 ± 0.5°C) and was 0.36°C higher in luteal females relative to follicular females and males (P = 0.0006 and P < 0.0001, respectively). Temperature increased with age, most notably in deep brain regions (0.6°C over 20 years, P = 0.0002), and varied spatially by 2.41 ± 0.46°C with highest temperatures in the thalamus. Brain temperature varied by time of day, especially in deep regions (0.86°C, P = 0.0001), and was lowest at night. From the healthy data we built HEATWAVE-a 4D map of human brain temperature. Testing the clinical relevance of HEATWAVE in patients, we found that lack of a daily brain temperature rhythm increased the odds of death in intensive care 21-fold (P = 0.016), whilst absolute temperature maxima or minima did not predict outcome. A warmer mean brain temperature was associated with survival (P = 0.035), however, and ageing by 10 years increased the odds of death 11-fold (P = 0.0002). Human brain temperature is higher and varies more than previously assumed-by age, sex, menstrual cycle, brain region, and time of day. This has major implications for temperature monitoring and management, with daily brain temperature rhythmicity emerging as one of the strongest single predictors of survival after brain injury. We conclude that daily rhythmic brain temperature variation-not absolute brain temperature-is one way in which human brain physiology may be distinguished from pathophysiology.
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Affiliation(s)
| | - Michael J Thrippleton
- Edinburgh Imaging (Royal Infirmary of Edinburgh) Facility, Edinburgh EH16 4SA, UK.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Francesca M Chappell
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Grant Mair
- Edinburgh Imaging (Royal Infirmary of Edinburgh) Facility, Edinburgh EH16 4SA, UK.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Ari Ercole
- Division of Anaesthesia, University of Cambridge, Box 93 Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Manuel Cabeleira
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Box 167, Cambridge Biomedical Campus, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | | | - Jonathan Rhodes
- Department of Anaesthesia, Critical Care and Pain Medicine, NHS Lothian, Room No. S8208 (2nd Floor), Royal Infirmary of Edinburgh, Edinburgh EH16 4SA, UK
| | - Ian Marshall
- Edinburgh Imaging (Royal Infirmary of Edinburgh) Facility, Edinburgh EH16 4SA, UK.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - John S O'Neill
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
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Hong D, van Asten JJA, Rankouhi SR, Thielen JW, Norris DG. Implications of the magnetic susceptibility difference between grey and white matter for single-voxel proton spectroscopy at 7 T. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 297:51-60. [PMID: 30359907 DOI: 10.1016/j.jmr.2018.10.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 09/13/2018] [Accepted: 10/11/2018] [Indexed: 06/08/2023]
Abstract
Magnetic susceptibility differences between grey matter (GM) and white matter (WM) can potentially affect lineshapes and chemical shifts in single-voxel spectroscopy. This study aimed to investigate the consequences and potential utility of these effects. Spectroscopy voxels were segmented into GM, WM, and cerebrospinal fluid based on T1-weighted images. GM and WM lineshapes were computed using multi-echo gradient-echo images to measure the frequency distribution. Twenty 7 Tesla single voxel spectra with corresponding T1-weighted images were acquired from the frontal and parietal lobes from five healthy human volunteers. Consistent frequency shifts (mean [±SD] 4.9 ± 2.0 Hz) and linewidth differences (2.4 ± 1.5 Hz) between the two tissue types were observed. Directly visible metabolites (creatine, choline, and myo-inositol) exhibited frequency shifts and linewidth differences that were consistent with a linear-weighted summation of their expected GM and WM distribution ratios. The magnetic susceptibility difference between GM and WM had a detectable effect on single-voxel proton spectra, which results in both frequency shifts and lineshape broadening. This effect can be used to estimate the relative metabolic distribution in the GM and WM for directly observable metabolites. Fractional distributions estimated with this method demonstrated good agreement with literature values for the selected metabolites.
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Affiliation(s)
- Donghyun Hong
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany.
| | - Jack J A van Asten
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Jan-Willem Thielen
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
| | - David G Norris
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany; Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands
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Yablonskiy DA, Sukstanskii AL. Effects of biological tissue structural anisotropy and anisotropy of magnetic susceptibility on the gradient echo MRI signal phase: theoretical background. NMR IN BIOMEDICINE 2017; 30:10.1002/nbm.3655. [PMID: 27862452 PMCID: PMC6375105 DOI: 10.1002/nbm.3655] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 07/18/2016] [Accepted: 09/09/2016] [Indexed: 05/11/2023]
Abstract
Quantitative susceptibility mapping is a potentially powerful technique for mapping tissue magnetic susceptibility from gradient recalled echo (GRE) MRI signal phase. In this review, we present up-to-date theoretical developments in analyzing the relationships between GRE signal phase and the underlying tissue microstructure and magnetic susceptibility at the cellular level. Two important phenomena contributing to the GRE signal phase are at the focus of this review - tissue structural anisotropy (e.g. cylindrical axonal bundles in white matter) and magnetic susceptibility anisotropy. One of the most intriguing and challenging problems in this field is calculating the so-called Lorentzian contribution to the phase shift induced by the local environment - magnetized tissue structures that have dimensions smaller than the imaging voxel (e.g. cells, cellular components, blood capillaries). In this review, we briefly discuss a "standard" approach to this problem, based on introduction of an imaginary Lorentzian cavity, as well as a more recent method - the generalized Lorentzian tensor approach (GLTA) - that is based on a statistical approach and a direct solution of the magnetostatic Maxwell equations. The latter adequately accounts for both types of anisotropy: the anisotropy of magnetic susceptibility and the structural tissue anisotropy. In the GLTA the frequency shift due to the local environment is characterized by the Lorentzian tensor L^, which has a substantially different structure than the susceptibility tensor χ^. While the components of χ^ are compartmental susceptibilities "weighted" by their volume fractions, the components of L^ are weighted by specific numerical factors depending on tissue geometrical microsymmetry. In multi-compartment structures, the components of the Lorentzian tensor also depend on the compartmental relaxation properties, hence the MR pulse sequence settings. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Dmitriy A. Yablonskiy
- Correspondence to: D.A. Yablonskiy, Mallinckrodt Institute of Radiology, St Louis, MO, USA.
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Maudsley AA, Goryawala MZ, Sheriff S. Effects of tissue susceptibility on brain temperature mapping. Neuroimage 2016; 146:1093-1101. [PMID: 27693198 DOI: 10.1016/j.neuroimage.2016.09.062] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/15/2016] [Accepted: 09/26/2016] [Indexed: 02/07/2023] Open
Abstract
A method for mapping of temperature over a large volume of the brain using volumetric proton MR spectroscopic imaging has been implemented and applied to 150 normal subjects. Magnetic susceptibility-induced frequency shifts in gray- and white-matter regions were measured and included as a correction in the temperature mapping calculation. Additional sources of magnetic susceptibility variations of the individual metabolite resonance frequencies were also observed that reflect the cellular-level organization of the brain metabolites, with the most notable differences being attributed to changes of the N-Acetylaspartate resonance frequency that reflect the intra-axonal distribution and orientation of the white-matter tracts with respect to the applied magnetic field. These metabolite-specific susceptibility effects are also shown to change with age. Results indicate no change of apparent brain temperature with age from 18 to 84 years old, with a trend for increased brain temperature throughout the cerebrum in females relative for males on the order of 0.1°C; slightly increased temperatures in the left hemisphere relative to the right; and a lower temperature of 0.3°C in the cerebellum relative to that of cerebral white-matter. This study presents a novel acquisition method for noninvasive measurement of brain temperature that is of potential value for diagnostic purposes and treatment monitoring, while also demonstrating limitations of the measurement due to the confounding effects of tissue susceptibility variations.
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Leutritz T, Hilfert L, Busse U, Smalla K, Speck O, Zhong K. Contribution of iron and protein contents from rat brain subcellular fractions to MR phase imaging. Magn Reson Med 2016; 77:2028-2039. [DOI: 10.1002/mrm.26288] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 12/14/2022]
Affiliation(s)
- T. Leutritz
- Dept. Biomedical Magnetic ResonanceOtto‐von‐Guericke UniversityMagdeburg Germany
| | - L. Hilfert
- Institute for ChemistryOtto‐von‐Guericke UniversityMagdeburg Germany
| | - U. Busse
- Institute of Apparatus and Environmental EngineeringOtto‐von‐Guericke UniversityMagdeburg Germany
| | - K.‐H. Smalla
- Center for Behavioral Brain Sciences Magdeburg
- Leibniz Institute for NeurobiologyMagdeburg Germany
| | - O. Speck
- Dept. Biomedical Magnetic ResonanceOtto‐von‐Guericke UniversityMagdeburg Germany
- Center for Behavioral Brain Sciences Magdeburg
- Leibniz Institute for NeurobiologyMagdeburg Germany
- German Center for Neurodegenerative Disease (DZNE)Site Magdeburg Germany
| | - K. Zhong
- Dept. Biomedical Magnetic ResonanceOtto‐von‐Guericke UniversityMagdeburg Germany
- High Magnetic Field Lab, Chinese Academy of SciencesHefei China
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10
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Rango M, Bonifati C, Bresolin N. Post-Activation Brain Warming: A 1-H MRS Thermometry Study. PLoS One 2015; 10:e0127314. [PMID: 26011731 PMCID: PMC4444346 DOI: 10.1371/journal.pone.0127314] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 04/14/2015] [Indexed: 11/24/2022] Open
Abstract
Purpose Temperature plays a fundamental role for the proper functioning of the brain. However, there are only fragmentary data on brain temperature (Tbr) and its regulation under different physiological conditions. Methods We studied Tbr in the visual cortex of 20 normal subjects serially with a wide temporal window under different states including rest, activation and recovery by a visual stimulation-Magnetic Resonance Spectroscopy Thermometry combined approach. We also studied Tbr in a control region, the centrum semiovale, under the same conditions. Results Visual cortex mean baseline Tbr was higher than mean body temperature (37.38 vs 36.60, P<0.001). During activation Tbr remained unchanged at first and then showed a small decrease (-0.20 C°) around the baseline value. After the end of activation Tbr increased consistently (+0.60 C°) and then returned to baseline values after some minutes. Centrum semiovale Tbr remained unchanged through rest, visual stimulation and recovery. Conclusion These findings have several implications, among them that neuronal firing itself is not a major source of heat release in the brain and that there is an aftermath of brain activation that lasts minutes before returning to baseline conditions.
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Affiliation(s)
- Mario Rango
- Department of Neurological Sciences, IRCCS Ca’ Granda-Ospedale Maggiore Policlinico Foundation, University of Milan, Milan, Italy
- Magnetic Resonance Spectroscopy Center, IRCCS Ca’ Granda-Ospedale Maggiore Policlinico Foundation, University of Milan, Milan, Italy
- * E-mail:
| | - Cristiana Bonifati
- Department of Neurological Sciences, IRCCS Ca’ Granda-Ospedale Maggiore Policlinico Foundation, University of Milan, Milan, Italy
- Magnetic Resonance Spectroscopy Center, IRCCS Ca’ Granda-Ospedale Maggiore Policlinico Foundation, University of Milan, Milan, Italy
| | - Nereo Bresolin
- Department of Neurological Sciences, IRCCS Ca’ Granda-Ospedale Maggiore Policlinico Foundation, University of Milan, Milan, Italy
- Magnetic Resonance Spectroscopy Center, IRCCS Ca’ Granda-Ospedale Maggiore Policlinico Foundation, University of Milan, Milan, Italy
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Yablonskiy DA, Sukstanskii AL. Generalized Lorentzian Tensor Approach (GLTA) as a biophysical background for quantitative susceptibility mapping. Magn Reson Med 2014; 73:757-64. [PMID: 25426775 DOI: 10.1002/mrm.25538] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/20/2014] [Accepted: 10/30/2014] [Indexed: 11/10/2022]
Abstract
PURPOSE Quantitative susceptibility mapping (QSM) is a potentially powerful technique for mapping tissue magnetic susceptibility from gradient recalled echo (GRE) MRI. Herein we aim to derive the relationships between GRE signal phase and the underlying tissue microstructure and magnetic susceptibility at the cellular level. METHODS We use Maxwell's equations and a statistical approach to derive the expression for the magnetic-susceptibility-induced MR signal frequency shift of the GRE signal in single- and multicompartment systems, in which inhomogeneous magnetic field is induced by the cellular constituents (proteins, lipids, iron, etc.) distributed in intra- and extracellular spaces. RESULTS We introduce the Generalized Lorentzian Tensor Approach (GLTA) that accounts for both types of anisotropy: the anisotropy of magnetic susceptibility and the structural tissue anisotropy. In the GLTA the frequency shift due to the local environment is characterized by the Lorentzian tensor L⁁ which has a substantially different structure than the susceptibility tensor χ⁁. While components of χ⁁ are simply compartmental susceptibilities "weighted" by their relative volumes, the components of L⁁ are weighted by specific numerical factors depending on tissue micro-symmetry and parameters related to the MR pulse sequence. We also provide equations bridging phenomenological and microscopic considerations. CONCLUSION The GLTA provides a consistent background for deciphering phase data.
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12
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Babourina-Brooks B, Wilson M, Arvanitis TN, Peet AC, Davies NP. MRS water resonance frequency in childhood brain tumours: a novel potential biomarker of temperature and tumour environment. NMR IN BIOMEDICINE 2014; 27:1222-9. [PMID: 25125325 PMCID: PMC4491353 DOI: 10.1002/nbm.3177] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 06/13/2014] [Accepted: 07/10/2014] [Indexed: 06/03/2023]
Abstract
(1)H MRS thermometry has been investigated for brain trauma and hypothermia monitoring applications but has not been explored in brain tumours. The proton resonance frequency (PRF) of water is dependent on temperature but is also influenced by microenvironment factors, such as fast proton exchange with macromolecules, ionic concentration and magnetic susceptibility. (1)H MRS has been utilized for brain tumour diagnostic and prognostic purposes in children; however, the water PRF measure may provide complementary information to further improve characterization. Water PRF values were investigated from a repository of MRS data acquired from childhood brain tumours and children with apparently normal brains. The cohort consisted of histologically proven glioma (22), medulloblastoma (19) and control groups (28, MRS in both the basal ganglia and parietal white matter regions). All data were acquired at 1.5 T using a short TE (30 ms) single voxel spectroscopy (PRESS) protocol. Water PRF values were calculated using methyl creatine and total choline. Spectral peak amplitude weighted averaging was used to improve the accuracy of the measurements. Mean PRF values were significantly larger for medulloblastoma compared with glioma, with a difference in the means of 0.0147 ppm (p < 0.05), while the mean PRF for glioma was significantly lower than for the healthy cohort, with a difference in the means of 0.0061 ppm (p < 0.05). This would suggest the apparent temperature of the glioma group was ~1.5 °C higher than the medulloblastomas and ~0.7 °C higher than a healthy brain. However, the PRF shift may not reflect a change in temperature, given that alterations in protein content, microstructure and ionic concentration contribute to PRF shifts. Measurement of these effects could also be used as a supplementary biomarker, and further investigation is required. This study has shown that the water PRF value has the potential to be used for characterizing childhood brain tumours, which has not been reported previously.
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Affiliation(s)
- Ben Babourina-Brooks
- School of Cancer Sciences, University of BirminghamBirmingham, West Midlands, UK
- Children's Hospital NHS Foundation TrustBirmingham, West Midlands, UK
| | - Martin Wilson
- School of Cancer Sciences, University of BirminghamBirmingham, West Midlands, UK
- Children's Hospital NHS Foundation TrustBirmingham, West Midlands, UK
| | - Theodoros N Arvanitis
- Children's Hospital NHS Foundation TrustBirmingham, West Midlands, UK
- Institute of Digital Healthcare, WMG, University of WarwickCoventry, UK
| | - Andrew C Peet
- School of Cancer Sciences, University of BirminghamBirmingham, West Midlands, UK
- Children's Hospital NHS Foundation TrustBirmingham, West Midlands, UK
| | - Nigel P Davies
- School of Cancer Sciences, University of BirminghamBirmingham, West Midlands, UK
- Imaging and Medical Physics, University Hospitals Birmingham NHS Foundation TrustBirmingham, West Midlands, UK
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Thrippleton MJ, Parikh J, Harris BA, Hammer SJ, Semple SIK, Andrews PJD, Wardlaw JM, Marshall I. Reliability of MRSI brain temperature mapping at 1.5 and 3 T. NMR IN BIOMEDICINE 2014; 27:183-90. [PMID: 24273188 PMCID: PMC4265254 DOI: 10.1002/nbm.3050] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 10/08/2013] [Accepted: 10/10/2013] [Indexed: 06/02/2023]
Abstract
MRSI permits the non-invasive mapping of brain temperature in vivo, but information regarding its reliability is lacking. We obtained MRSI data from 31 healthy male volunteers [age range, 22-40 years; mean ± standard deviation (SD), 30.5 ± 5.0 years]. Eleven subjects (age range, 23-40 years; mean ± SD, 30.5 ± 5.2 years) were invited to receive four point-resolved spectroscopy MRSI scans on each of 3 days in both 1.5-T (TR/TE = 1000/144 ms) and 3-T (TR/TE = 1700/144 ms) clinical scanners; a further 20 subjects (age range, 22-40 years; mean ± SD, 30.5 ± 4.9 years) were scanned on a single occasion at 3 T. Data were fitted in the time domain to determine the water-N-acetylaspartate chemical shift difference, from which the temperature was estimated. Temperature data were analysed using a linear mixed effects model to determine variance components and systematic temperature changes during the scanning sessions. To characterise the effects of instrumental drift on apparent MRSI brain temperature, a temperature-controlled phantom was constructed and scanned on multiple occasions. Components of apparent in vivo temperature variability at 1.5 T/3 T caused by inter-subject (0.18/0.17 °C), inter-session (0.18/0.15 °C) and within-session (0.36/0.14 °C) effects, as well as voxel-to-voxel variation (0.59/0.54 °C), were determined. There was a brain cooling effect during in vivo MRSI of 0.10 °C [95% confidence interval (CI): -0.110, -0.094 °C; p < 0.001] and 0.051 °C (95% CI: -0.054, -0.048 °C; p < 0.001) per scan at 1.5 T and 3 T, respectively, whereas phantom measurements revealed minimal drift in apparent MRSI temperature relative to fibre-optic temperature measurements. The mean brain temperature at 3 T was weakly associated with aural (R = 0.55, p = 0.002) and oral (R = 0.62, p < 0.001) measurements of head temperature. In conclusion, the variability associated with MRSI brain temperature mapping was quantified. Repeatability was somewhat higher at 3 T than at 1.5 T, although subtle spatial and temporal variations in apparent temperature were demonstrated at both field strengths. Such data should assist in the efficient design of future clinical studies.
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Affiliation(s)
- Michael J Thrippleton
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of EdinburghEdinburgh, UK
| | - Jehill Parikh
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of EdinburghEdinburgh, UK
| | | | - Steven J Hammer
- School of Engineering and Physical Sciences, Heriot-Watt UniversityEdinburgh, UK
| | - Scott I K Semple
- Clinical Research Imaging Centre, Centre for Cardiovascular Sciences, University of EdinburghEdinburgh, UK
| | - Peter J D Andrews
- Centre for Clinical Brain Sciences, University of EdinburghEdinburgh, UK
| | - Joanna M Wardlaw
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of EdinburghEdinburgh, UK
| | - Ian Marshall
- Brain Research Imaging Centre, Centre for Clinical Brain Sciences, University of EdinburghEdinburgh, UK
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Sukstanskii AL, Yablonskiy DA. On the role of neuronal magnetic susceptibility and structure symmetry on gradient echo MR signal formation. Magn Reson Med 2014; 71:345-53. [PMID: 23382087 PMCID: PMC3657601 DOI: 10.1002/mrm.24629] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 11/20/2012] [Accepted: 12/15/2012] [Indexed: 12/13/2022]
Abstract
PURPOSE Phase images obtained by gradient-recalled echo (GRE) MRI provide new contrast in the brain that is distinct from that obtained with conventional T1-weighted and T2-weighted images. The results are especially intriguing in white matter where both signal amplitude and phase display anisotropic properties. However, the biophysical origins of these phenomena are not well understood. The goal of this article is to provide a comprehensive theory of GRE signal formation based on a realistic model of neuronal structure. METHODS We use Maxwell equations to find the distribution of magnetic field induced by myelin sheath and axon. We account for both anisotropy of neuronal tissue "magnetic micro-architecture" and anisotropy of myelin sheath magnetic susceptibility. RESULTS Model describes GRE signal comprising of three compartments-axonal, myelin, and extracellular. Both axonal and myelin water signals have frequency shifts that are affected by the magnetic susceptibility anisotropy of long molecules forming lipid bilayer membranes. These parts of frequency shifts reach extrema for axon oriented perpendicular to the magnetic field and are zeros in a parallel case. Myelin water signal is substantially non-monoexponential. CONCLUSIONS Both, anisotropy of neuronal tissue "magnetic micro-architecture" and anisotropy of myelin sheath magnetic susceptibility, are important for describing GRE signal phase and magnitude.
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Esteve V, Celda B, Martínez-Bisbal MC. Use of 1H and 31P HRMAS to evaluate the relationship between quantitative alterations in metabolite concentrations and tissue features in human brain tumour biopsies. Anal Bioanal Chem 2012; 403:2611-25. [PMID: 22552786 DOI: 10.1007/s00216-012-6001-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 03/28/2012] [Accepted: 03/30/2012] [Indexed: 11/29/2022]
Abstract
Quantitative multinuclear high-resolution magic angle spinning was performed in order to determine the tissue pH values of and the absolute metabolite concentrations in 33 samples of human brain tumour tissue. Metabolite concentrations were quantified by 1D (1)H and (31)P HRMAS using the electronic reference to in vivo concentrations (ERETIC) synthetic signal. (1)H-(1)H homonuclear and (1)H-(31)P heteronuclear correlation experiments enabled the direct assessment of the (1)H-(31)P spin systems for signals that suffered from overlapping in the 1D (1)H spectra, and linked the information present in the 1D (1)H and (31)P spectra. Afterwards, the main histological features were determined, and high heterogeneity in the tumour content, necrotic content and nonaffected tissue content was observed. The metabolite profiles obtained by HRMAS showed characteristics typical of tumour tissues: rather low levels of energetic molecules and increased concentrations of protective metabolites. Nevertheless, these characteristics were more strongly correlated with the total amount of living tissue than with the tumour cell contents of the samples alone, which could indicate that the sampling conditions make a significant contribution aside from the effect of tumour development in vivo. The use of methylene diphosphonic acid as a chemical shift and concentration reference for the (31)P HRMAS spectra of tissues presented important drawbacks due to its interaction with the tissue. Moreover, the pH data obtained from (31)P HRMAS enabled us to establish a correlation between the pH and the distance between the N(CH(3))(3) signals of phosphocholine and choline in (1)H spectra of the tissue in these tumour samples.
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Affiliation(s)
- Vicent Esteve
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine, Burjassot, Spain
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Pan JW, Lo KM, Hetherington HP. Role of very high order and degree B0 shimming for spectroscopic imaging of the human brain at 7 tesla. Magn Reson Med 2011; 68:1007-17. [PMID: 22213108 DOI: 10.1002/mrm.24122] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 11/21/2011] [Accepted: 11/23/2011] [Indexed: 01/19/2023]
Abstract
With the advent of ultrahigh field systems (7 T), significant improvements in spectroscopic imaging (SI) studies of the human brain have been anticipated. These gains are dependent upon the achievable B0 homogeneity, both globally (σB0Global, over the entire regions of interest or slice) and locally (σB0Global, influencing the linewidth of individual SI voxels within the regions of interest). Typically the B0 homogeneity is adjusted using shim coils with spatial distributions modeled on spherical harmonics which can be characterized by a degree (radial dependence) and order (azimuthal symmetry). However, the role of very high order and degree shimming (e.g., 3rd and 4th degree) in MRSI studies has been controversial. Measurements of σB0Global and σB0Local were determined from B0 field maps of 64×64 resolution. In a 10 mm thick slice taken through the region of the subcortical nuclei, we find that in comparison to 1st-2nd degree shims, use of 1st-3rd and 1st-4th degree shims reduces σB0Global by 29% and 55%, respectively. Using a SI voxel size of ∼1cc with an estimate of σB0Local from 3×3×3 B0 map pixels in this subcortical region, the number of pixels with σB0Local of less than 5 Hz increased from 24 to 59% with 1st-3rd and 1st-4th over 1st-2nd degree shims, respectively.
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Affiliation(s)
- Jullie W Pan
- Department of Neurosurgery, Yale University, New Haven, Connecticut 06511-0820, USA.
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