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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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Sung D, Risk BB, Kottke PA, Allen JW, Nahab F, Fedorov AG, Fleischer CC. Comparisons of healthy human brain temperature predicted from biophysical modeling and measured with whole brain MR thermometry. Sci Rep 2022; 12:19285. [PMID: 36369468 PMCID: PMC9652378 DOI: 10.1038/s41598-022-22599-x] [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: 07/16/2022] [Accepted: 10/17/2022] [Indexed: 11/13/2022] Open
Abstract
Brain temperature is an understudied parameter relevant to brain injury and ischemia. To advance our understanding of thermal dynamics in the human brain, combined with the challenges of routine experimental measurements, a biophysical modeling framework was developed to facilitate individualized brain temperature predictions. Model-predicted brain temperatures using our fully conserved model were compared with whole brain chemical shift thermometry acquired in 30 healthy human subjects (15 male and 15 female, age range 18-36 years old). Magnetic resonance (MR) thermometry, as well as structural imaging, angiography, and venography, were acquired prospectively on a Siemens Prisma whole body 3 T MR scanner. Bland-Altman plots demonstrate agreement between model-predicted and MR-measured brain temperatures at the voxel-level. Regional variations were similar between predicted and measured temperatures (< 0.55 °C for all 10 cortical and 12 subcortical regions of interest), and subcortical white matter temperatures were higher than cortical regions. We anticipate the advancement of brain temperature as a marker of health and injury will be facilitated by a well-validated computational model which can enable predictions when experiments are not feasible.
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Affiliation(s)
- Dongsuk Sung
- grid.213917.f0000 0001 2097 4943Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA USA
| | - Benjamin B. Risk
- grid.189967.80000 0001 0941 6502Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA USA
| | - Peter A. Kottke
- grid.213917.f0000 0001 2097 4943Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA USA
| | - Jason W. Allen
- grid.213917.f0000 0001 2097 4943Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA USA ,grid.189967.80000 0001 0941 6502Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA USA ,grid.189967.80000 0001 0941 6502Department of Neurology, Emory University School of Medicine, Atlanta, GA USA
| | - Fadi Nahab
- grid.189967.80000 0001 0941 6502Department of Neurology, Emory University School of Medicine, Atlanta, GA USA
| | - Andrei G. Fedorov
- grid.213917.f0000 0001 2097 4943Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA USA ,grid.213917.f0000 0001 2097 4943Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA USA
| | - Candace C. Fleischer
- grid.213917.f0000 0001 2097 4943Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA USA ,grid.189967.80000 0001 0941 6502Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA USA ,grid.213917.f0000 0001 2097 4943Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA USA ,grid.189967.80000 0001 0941 6502Wesley Woods Health Center, Emory University School of Medicine, 1841 Clifton Road, Atlanta, GA 30329 USA
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Verma V, Lange F, Bainbridge A, Harvey-Jones K, Robertson NJ, Tachtsidis I, Mitra S. Brain temperature monitoring in newborn infants: Current methodologies and prospects. Front Pediatr 2022; 10:1008539. [PMID: 36268041 PMCID: PMC9577084 DOI: 10.3389/fped.2022.1008539] [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] [Received: 07/31/2022] [Accepted: 09/15/2022] [Indexed: 02/02/2023] Open
Abstract
Brain tissue temperature is a dynamic balance between heat generation from metabolism, passive loss of energy to the environment, and thermoregulatory processes such as perfusion. Perinatal brain injuries, particularly neonatal encephalopathy, and seizures, have a significant impact on the metabolic and haemodynamic state of the developing brain, and thereby likely induce changes in brain temperature. In healthy newborn brains, brain temperature is higher than the core temperature. Magnetic resonance spectroscopy (MRS) has been used as a viable, non-invasive tool to measure temperature in the newborn brain with a reported accuracy of up to 0.2 degrees Celcius and a precision of 0.3 degrees Celcius. This measurement is based on the separation of chemical shifts between the temperature-sensitive water peaks and temperature-insensitive singlet metabolite peaks. MRS thermometry requires transport to an MRI scanner and a lengthy single-point measurement. Optical monitoring, using near infrared spectroscopy (NIRS), offers an alternative which overcomes this limitation in its ability to monitor newborn brain tissue temperature continuously at the cot side in real-time. Near infrared spectroscopy uses linear temperature-dependent changes in water absorption spectra in the near infrared range to estimate the tissue temperature. This review focuses on the currently available methodologies and their viability for accurate measurement, the potential benefits of monitoring newborn brain temperature in the neonatal intensive care unit, and the important challenges that still need to be addressed.
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Affiliation(s)
- Vinita Verma
- Institute for Women's Health, University College London, London, United Kingdom
| | - Frederic Lange
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Alan Bainbridge
- Medical Physics and Engineering, University College London Hospital, London, United Kingdom
| | - Kelly Harvey-Jones
- Institute for Women's Health, University College London, London, United Kingdom
| | - Nicola J Robertson
- Institute for Women's Health, University College London, London, United Kingdom
| | - Ilias Tachtsidis
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Subhabrata Mitra
- Institute for Women's Health, University College London, London, United Kingdom
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Machin G, Howell K, Allen J, Simpson R. Focus collection on Thermal Imaging in Medicine. Physiol Meas 2019; 40:100301. [PMID: 31665126 DOI: 10.1088/1361-6579/ab3b8a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Graham Machin
- National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW, United Kingdom
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Antonacci MA, McHugh C, Kelley M, McCallister A, Degan S, Branca RT. Direct detection of brown adipose tissue thermogenesis in UCP1-/- mice by hyperpolarized 129Xe MR thermometry. Sci Rep 2019; 9:14865. [PMID: 31619741 PMCID: PMC6795875 DOI: 10.1038/s41598-019-51483-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 10/02/2019] [Indexed: 12/19/2022] Open
Abstract
Brown adipose tissue (BAT) is a type of fat specialized in non-shivering thermogenesis. While non-shivering thermogenesis is mediated primarily by uncoupling protein 1 (UCP1), the development of the UCP1 knockout mouse has enabled the study of possible UCP1-independent non-shivering thermogenic mechanisms, whose existence has been shown so far only indirectly in white adipose tissue and still continues to be a matter of debate in BAT. In this study, by using magnetic resonance thermometry with hyperpolarized xenon, we produce the first direct evidence of UCP1-independent BAT thermogenesis in knockout mice. We found that, following adrenergic stimulation, the BAT temperature of knockout mice increases more and faster than rectal temperature. While with this study we cannot exclude or separate the physiological effect of norepinephrine on core body temperature, the fast increase of iBAT temperature seems to suggest the existence of a possible UCP1-independent thermogenic mechanism responsible for this temperature increase.
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Affiliation(s)
- Michael A Antonacci
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Physics, Saint Vincent College, Latrobe, Pennsylvania, United States of America
| | - Christian McHugh
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Michele Kelley
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Andrew McCallister
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Simone Degan
- Department of Radiology, Duke University, Durham, North Carolina, United States of America
| | - Rosa T Branca
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
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Machin G, Simpson R, McEvoy HC, Whittam A. NPL contributions to the standardisation and validation of contemporary medical thermometry methods. Physiol Meas 2019; 40:05TR01. [PMID: 30943464 DOI: 10.1088/1361-6579/ab15b0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Since the advent of reliable mercury-in-glass thermometers in the latter part of the 19th century the practice of clinical thermometry was thought to be a solved issue. However with advances in technology there has, in recent decades, been a proliferation of temperature measurement methods applied to medical science. Many of these have been introduced because of the clinical benefit they confer, nevertheless, in some cases the metrological foundation and infrastructure to ensure sound measurement was not in place. This paper will focus on the standardisation activity undertaken by the UK's National Physical Laboratory (NPL) to support reliable temperature measurement, using a number of innovative methods, in a clinical setting.
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Affiliation(s)
- G Machin
- Temperature and Humidity Group, National Physical Laboratory, Teddington, London, United Kingdom. Author to whom any correspondence should be addressed
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Verius M, Frank F, Gizewski E, Broessner G. Magnetic Resonance Spectroscopy Thermometry at 3 Tesla: Importance of Calibration Measurements. Ther Hypothermia Temp Manag 2018; 9:146-155. [PMID: 30457932 DOI: 10.1089/ther.2018.0027] [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: 01/08/2023] Open
Abstract
To demonstrate the importance of calibration measurements in 3 Tesla proton magnetic resonance (MR) spectroscopy (1H-MRS) thermometry for human brain temperature estimation for routine clinical applications. In vitro proton MR spectroscopy to obtain calibration constants of the water-chemical shift was conducted at 3 Tesla with a temperature-controlled phantom, containing a pH-buffered aqueous solution of N-acetyl aspartate (NAA), creatine (Cr), methylene protons of Cr (Cr2), dimethyl silapentane sulfonic acid (DSS), and sodium formate (NaFor). Estimations of absolute human brain temperature were performed utilizing the correlation of temperature to the water-chemical shift for the resonances of NAA, Cr, and Cr2. Data for calibration of the metabolites' chemical shift differences and in vivo temperature estimations were acquired with single-voxel point-resolved spectroscopy (PRESS) sequences (repetition time/echo time = 2000/30 ms; voxel size 2 × 2 × 2 cm3). Spectroscopy data were quantified in the time-domain, and a Pearson correlation analysis was performed to estimate the correlation between the chemical shift of metabolites and measured temperatures. The correlation coefficients (r) of our calibration measurements were NAA 0.9975 (±0.0609), Cr -0.9979 (±0.0621), Cr2 - 0.9973 (±0.0577), DSS -0.9976 (±0.0615), and NaFor -0.8132 (±2.348). The mean calculated brain temperature was 37.78 ± 1.447°C, and the mean tympanic temperature was 36.83 ± 0.2456°C. Calculated temperatures derived from Cr and Cr2 provided significant (p = 0.0241 and p = 0.0210, respectively) correlations with measured temperatures (r = 0.4108 and r = -0.4194, respectively). Calibration measurements are vital for 1H-MRS thermometry. Small numeric differences in measured signal and data preprocessing without any calibration measurements reduce accuracy of temperature calculations, which indicates that calculated temperatures should be interpreted with caution. Application of this method for clinical purposes warrants further investigation and a more practical approach.
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Affiliation(s)
- Michael Verius
- 1 Medizinische Universität Innsbruck, Neuroimaging Research Core Facility, Innsbruck, Austria
| | - Florian Frank
- 2 Medizinische Universität Innsbruck, Universitätsklinik für Neurologie, Innsbruck, Austria
| | - Elke Gizewski
- 1 Medizinische Universität Innsbruck, Neuroimaging Research Core Facility, Innsbruck, Austria.,3 Medizinische Universität Innsbruck, Universitätsklinik für Neuroradiologie, Innsbruck, Austria
| | - Gregor Broessner
- 2 Medizinische Universität Innsbruck, Universitätsklinik für Neurologie, Innsbruck, Austria
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Quantitative magnetic resonance imaging phantoms: A review and the need for a system phantom. Magn Reson Med 2017; 79:48-61. [DOI: 10.1002/mrm.26982] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 09/01/2017] [Accepted: 10/04/2017] [Indexed: 01/16/2023]
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Multiparametric quantification of thermal heterogeneity within aqueous materials by water 1H NMR spectroscopy: Paradigms and algorithms. PLoS One 2017; 12:e0178431. [PMID: 28552959 PMCID: PMC5446178 DOI: 10.1371/journal.pone.0178431] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Accepted: 05/12/2017] [Indexed: 11/24/2022] Open
Abstract
Processes involving heat generation and dissipation play an important role in the performance of numerous materials. The behavior of (semi-)aqueous materials such as hydrogels during production and application, but also properties of biological tissue in disease and therapy (e.g., hyperthermia) critically depend on heat regulation. However, currently available thermometry methods do not provide quantitative parameters characterizing the overall temperature distribution within a volume of soft matter. To this end, we present here a new paradigm enabling accurate, contactless quantification of thermal heterogeneity based on the line shape of a water proton nuclear magnetic resonance (1H NMR) spectrum. First, the 1H NMR resonance from water serving as a "temperature probe" is transformed into a temperature curve. Then, the digital points of this temperature profile are used to construct a histogram by way of specifically developed algorithms. We demonstrate that from this histogram, at least eight quantitative parameters describing the underlying statistical temperature distribution can be computed: weighted median, weighted mean, standard deviation, range, mode(s), kurtosis, skewness, and entropy. All mathematical transformations and calculations are performed using specifically programmed EXCEL spreadsheets. Our new paradigm is helpful in detailed investigations of thermal heterogeneity, including dynamic characteristics of heat exchange at sub-second temporal resolution.
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