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Thomas DC, Oros-Peusquens AM, Schöneck M, Willuweit A, Abbas Z, Zimmermann M, Felder J, Celik A, Shah NJ. In Vivo Measurement of Rat Brain Water Content at 9.4 T MR Using Super-Resolution Reconstruction: Validation With Ex Vivo Experiments. J Magn Reson Imaging 2024; 60:161-172. [PMID: 37855368 DOI: 10.1002/jmri.29061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 10/20/2023] Open
Abstract
BACKGROUND Given that changes in brain water content are often correlated with disease, investigating water content non-invasively and in vivo could lead to a better understanding of the pathogenesis of several neurologic diseases. PURPOSE To adapt a super-resolution-based technique, previously developed for humans, to the rat brain and report in vivo high-resolution (HR) water content maps in comparison with ex vivo wet/dry methods. STUDY TYPE Prospective. ANIMAL MODEL Eight healthy male Wistar rats. FIELD STRENGTH/SEQUENCE 9.4-T, multi-echo gradient-echo (mGRE) sequence. ASSESSMENT Using super-resolution reconstruction (SRR), a HR mGRE image (200 μm isotropic) was reconstructed from three low-resolution (LR) orthogonal whole-brain images in each animal, which was followed by water content mapping in vivo. The animals were subsequently sacrificed, the brains excised and divided into five regions (front left, front right, middle left, middle right, and cerebellum-brainstem regions), and the water content was measured ex vivo using wet/dry measurements as the reference standard. The water content values of the in vivo and ex vivo methods were then compared for the whole brain and also for the different regions separately. STATISTICAL TESTS Friedman's non-parametric test was used to test difference between the five regions, and Pearson's correlation coefficient was used for correlation between in vivo and ex vivo measurements. A P-value <0.05 was considered statistically significant. RESULTS Water content values derived from in vivo MR measurements showed strong correlations with water content measured ex vivo at a regional level (r = 0.902). Different brain regions showed significantly different water content values. Water content values were highest in the frontal brain, followed by the midbrain, and lowest in the cerebellum and brainstem regions. DATA CONCLUSION An in vivo technique to achieve HR isotropic water content maps in the rat brain using SRR was adopted in this study. The MRI-derived water content values obtained using the technique showed strong correlations with water content values obtained using ex vivo wet/dry methods. LEVEL OF EVIDENCE 1 TECHNICAL EFFICACY: Stage 1.
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Affiliation(s)
- Dennis C Thomas
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
- Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | | | - Michael Schöneck
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
| | - Antje Willuweit
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
| | - Zaheer Abbas
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
| | - Markus Zimmermann
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
| | - Jörg Felder
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
- RWTH Aachen University, Aachen, Germany
| | - Avdo Celik
- Institute of Neuroscience and Medicine 11, INM-11, JARA, Forschungszentrum Jülich, Jülich, Germany
| | - Nadim Joni Shah
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
- Institute of Neuroscience and Medicine 11, INM-11, JARA, Forschungszentrum Jülich, Jülich, Germany
- JARA-BRAIN-Translational Medicine, Aachen, Germany
- Department of Neurology, RWTH Aachen University, Aachen, Germany
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Gogishvili A, Farrher E, Doppler CEJ, Seger A, Sommerauer M, Shah NJ. Quantification of the neurochemical profile of the human putamen using STEAM MRS in a cohort of elderly subjects at 3 T and 7 T: Ruminations on the correction strategy for the tissue voxel composition. PLoS One 2023; 18:e0286633. [PMID: 37267283 DOI: 10.1371/journal.pone.0286633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 05/19/2023] [Indexed: 06/04/2023] Open
Abstract
The aim of this work is to quantify the metabolic profile of the human putamen in vivo in a cohort of elderly subjects using single-voxel proton magnetic resonance spectroscopy. To obtain metabolite concentrations specific to the putamen, we investigated a correction method previously proposed to account for the tissue composition of the volume of interest. We compared the method with the conventional approach, which a priori assumes equal metabolite concentrations in GM and WM. Finally, we compared the concentrations acquired at 3 Tesla (T) and 7 T MRI scanners. Spectra were acquired from 15 subjects (age: 67.7 ± 8.3 years) at 3 T and 7 T, using an ultra-short echo time, stimulated echo acquisition mode sequence. To robustly estimate the WM-to-GM metabolite concentration ratio, five additional subjects were measured for whom the MRS voxel was deliberately shifted from the putamen in order to increase the covered amount of surrounding WM. The concentration and WM-to-GM concentration ratio for 16 metabolites were reliably estimated. These ratios ranged from ~0.3 for γ-aminobutyric acid to ~4 for N-acetylaspartylglutamate. The investigated correction method led to significant changes in concentrations compared to the conventional method, provided that the ratio significantly differed from unity. Finally, we demonstrated that differences in tissue voxel composition cannot fully account for the observed concentration difference between field strengths. We provide not only a fully comprehensive quantification of the neurochemical profile of the putamen in elderly subjects, but also a quantification of the WM-to-GM concentration ratio. This knowledge may serve as a basis for future studies with varying tissue voxel composition, either due to tissue atrophy, inconsistent voxel positioning or simply when pooling data from different voxel locations.
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Affiliation(s)
- Ana Gogishvili
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
- Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Engineering Physics Department, Georgian Technical University, Tbilisi, Georgia
| | - Ezequiel Farrher
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
| | - Christopher E J Doppler
- Cognitive Neuroscience, Institute of Neuroscience and Medicine 3, INM-3, Forschungszentrum Jülich, Jülich, Germany
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Aline Seger
- Cognitive Neuroscience, Institute of Neuroscience and Medicine 3, INM-3, Forschungszentrum Jülich, Jülich, Germany
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Michael Sommerauer
- Cognitive Neuroscience, Institute of Neuroscience and Medicine 3, INM-3, Forschungszentrum Jülich, Jülich, Germany
- Department of Neurology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - N Jon Shah
- Institute of Neuroscience and Medicine 4, INM-4, Forschungszentrum Jülich, Jülich, Germany
- Institute of Neuroscience and Medicine 11, INM-11, JARA, Forschungszentrum Jülich, Jülich, Germany
- JARA - BRAIN - Translational Medicine, Aachen, Germany
- Department of Neurology, RWTH Aachen University, Aachen, Germany
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3
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Yu B, Song C, Feng CL, Zhang J, Wang Y, Zhu YM, Zhang L, Ji XM, Tian XF, Cheng GF, Chen WL, Zablotskii V, Wang H, Zhang X. Effects of gradient high-field static magnetic fields on diabetic mice. Zool Res 2023; 44:249-258. [PMID: 36650064 PMCID: PMC10083230 DOI: 10.24272/j.issn.2095-8137.2022.460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 01/11/2023] [Indexed: 01/15/2023] Open
Abstract
Although 9.4 T magnetic resonance imaging (MRI) has been tested in healthy volunteers, its safety in diabetic patients is unclear. Furthermore, the effects of high static magnetic fields (SMFs), especially gradient vs. uniform fields, have not been investigated in diabetics. Here, we investigated the consequences of exposure to 1.0-9.4 T high SMFs of different gradients (>10 T/m vs. 0-10 T/m) on type 1 diabetic (T1D) and type 2 diabetic (T2D) mice. We found that 14 h of prolonged treatment of gradient (as high as 55.5 T/m) high SMFs (1.0-8.6 T) had negative effects on T1D and T2D mice, including spleen, hepatic, and renal tissue impairment and elevated glycosylated serum protein, blood glucose, inflammation, and anxiety, while 9.4 T quasi-uniform SMFs at 0-10 T/m did not induce the same effects. In regular T1D mice (blood glucose ≥16.7 mmol/L), the >10 T/m gradient high SMFs increased malondialdehyde ( P<0.01) and decreased superoxide dismutase ( P<0.05). However, in the severe T1D mice (blood glucose ≥30.0 mmol/L), the >10 T/m gradient high SMFs significantly increased tissue damage and reduced survival rate. In vitro cellular studies showed that gradient high SMFs increased cellular reactive oxygen species and apoptosis and reduced MS-1 cell number and proliferation. Therefore, this study showed that prolonged exposure to high-field (1.0-8.6 T) >10 T/m gradient SMFs (35-1 380 times higher than that of current clinical MRI) can have negative effects on diabetic mice, especially mice with severe T1D, whereas 9.4 T high SMFs at 0-10 T/m did not produce the same effects, providing important information for the future development and clinical application of SMFs, especially high-field MRI.
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Affiliation(s)
- Biao Yu
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Chao Song
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Chuan-Lin Feng
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jing Zhang
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Ying Wang
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yi-Ming Zhu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
| | - Lei Zhang
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Xin-Miao Ji
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
| | - Xiao-Fei Tian
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
| | - Guo-Feng Cheng
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Wei-Li Chen
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
| | - Vitalii Zablotskii
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic
- International Magnetobiology Frontier Research Center, Science Island, Hefei, Anhui 230031, China
| | - Hua Wang
- Department of Oncology, First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, China
| | - Xin Zhang
- High Magnetic Field Laboratory, CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, Anhui 230026, China
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, Anhui, 230601, China
- International Magnetobiology Frontier Research Center, Science Island, Hefei, Anhui 230031, China. E-mail:
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4
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Zhang Y, Huang P, Wang X, Xu Q, Liu Y, Jin Z, Li Y, Cheng Z, Tang R, Chen S, He N, Yan F, Haacke EM. Visualizing the deep cerebellar nuclei using quantitative susceptibility mapping: An application in healthy controls, Parkinson's disease patients and essential tremor patients. Hum Brain Mapp 2023; 44:1810-1824. [PMID: 36502376 PMCID: PMC9921226 DOI: 10.1002/hbm.26178] [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: 07/03/2022] [Revised: 10/20/2022] [Accepted: 11/27/2022] [Indexed: 12/14/2022] Open
Abstract
The visualization and identification of the deep cerebellar nuclei (DCN) (dentate [DN], interposed [IN] and fastigial nuclei [FN]) are particularly challenging. We aimed to visualize the DCN using quantitative susceptibility mapping (QSM), predict the contrast differences between QSM and T2* weighted imaging, and compare the DCN volume and susceptibility in movement disorder populations and healthy controls (HCs). Seventy-one Parkinson's disease (PD) patients, 39 essential tremor patients, and 80 HCs were enrolled. The PD patients were subdivided into tremor dominant (TD) and postural instability/gait difficulty (PIGD) groups. A 3D strategically acquired gradient echo MR imaging protocol was used for each subject to obtain the QSM data. Regions of interest were drawn manually on the QSM data to calculate the volume and susceptibility. Correlation analysis between the susceptibility and either age or volume was performed and the intergroup differences of the volume and magnetic susceptibility in all the DCN structures were evaluated. For the most part, all the DCN structures were clearly visualized on the QSM data. The susceptibility increased as a function of volume for both the HC group and disease groups in the DN and IN (p < .001) but not the FN (p = .74). Only the volume of the FN in the TD-PD group was higher than that in the HCs (p = .012), otherwise, the volume and susceptibility among these four groups did not differ significantly. In conclusion, QSM provides clear visualization of the DCN structures. The results for the volume and susceptibility of the DCN can be used as baseline references in future studies of movement disorders.
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Affiliation(s)
- Youmin Zhang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Pei Huang
- Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xinhui Wang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiuyun Xu
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
| | - Yu Liu
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhijia Jin
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan Li
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zenghui Cheng
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Rongbiao Tang
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shengdi Chen
- Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Naying He
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Fuhua Yan
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - E Mark Haacke
- Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA.,Department of Radiology, Wayne State University, Detroit, Michigan, USA
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5
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Wu X, Tao R, Zhang T, Liu X, Wang J, Zhang Z, Zhao X, Yang P. Biomedical applications of terahertz spectra in clinical and molecular pathology of human glioma. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 285:121933. [PMID: 36208578 DOI: 10.1016/j.saa.2022.121933] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/22/2022] [Accepted: 09/25/2022] [Indexed: 06/16/2023]
Abstract
Gliomas are the most common type of primary tumor originating in the central nervous system of adults. Tumor histological type, pathological grade, and molecular pathology are significant prognosis and predictive factors. In this study, we were aiming to predict histological type and molecular pathological features based on terahertz time-domain spectroscopy technology. Nine gliomas with different grades, one meningioma, and one lymphoma were enrolled. There were significant differences in terahertz absorption coefficient between normal brain tissue, tumoral-periphery, and tumoral-center tissue in specific frequency bands (0.2-1.4 THz). Histological type, pathological grade, and glioma-specific biomarkers were closely related to the terahertz absorption coefficient in both tumoral-periphery and tumoral-center tissues. Interestingly, tumoral-periphery showed more obvious differences than tumoral-center tissues in almost all aspects. All the results show that the terahertz technology has potential application value in the intraoperative real-time glioma recognition and diagnosis of glioma histological and molecular pathological features.
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Affiliation(s)
- Xianhao Wu
- School of Automation and Electrical Engineering, University of Science and Technology Beijing, Beijing, China
| | - Rui Tao
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Tianyao Zhang
- School of Automation and Electrical Engineering, University of Science and Technology Beijing, Beijing, China
| | - Xing Liu
- Department of Pathology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jiangfei Wang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Zhaohui Zhang
- School of Automation and Electrical Engineering, University of Science and Technology Beijing, Beijing, China
| | - Xiaoyan Zhao
- School of Automation and Electrical Engineering, University of Science and Technology Beijing, Beijing, China.
| | - Pei Yang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China; Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.
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6
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Oishi H, Takemura H, Amano K. Macromolecular tissue volume mapping of lateral geniculate nucleus subdivisions in living human brains. Neuroimage 2023; 265:119777. [PMID: 36462730 DOI: 10.1016/j.neuroimage.2022.119777] [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: 03/08/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
The lateral geniculate nucleus (LGN) is a key thalamic nucleus in the visual system, which has an important function in relaying retinal visual input to the visual cortex. The human LGN is composed mainly of magnocellular (M) and parvocellular (P) subdivisions, each of which has different stimulus selectivity in neural response properties. Previous studies have discussed the potential relationship between LGN subdivisions and visual disorders based on psychophysical data on specific types of visual stimuli. However, these relationships remain speculative because non-invasive measurements of these subdivisions are difficult due to the small size of the LGN. Here we propose a method to identify these subdivisions by combining two structural MR measures: high-resolution proton-density weighted images and macromolecular tissue volume (MTV) maps. We defined the M and P subdivisions based on MTV fraction data and tested the validity of the definition by (1) comparing the data with that from human histological studies, (2) comparing the data with functional magnetic resonance imaging measurements on stimulus selectivity, and (3) analyzing the test-retest reliability. The findings demonstrated that the spatial organization of the M and P subdivisions was consistent across subjects and in line with LGN subdivisions observed in human histological data. Moreover, the difference in stimulus selectivity between the subdivisions identified using MTV was consistent with previous physiology literature. The definition of the subdivisions based on MTV was shown to be robust over measurements taken on different days. These results suggest that MTV mapping is a promising approach for evaluating the tissue properties of LGN subdivisions in living humans. This method potentially will enable neuroscientific and clinical hypotheses about the human LGN subdivisions to be tested.
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Affiliation(s)
- Hiroki Oishi
- Center for Information and Neural Networks (CiNet), Advanced ICT Research Institute, National Institute of Information and Communications Technology, Suita 565-0871, Japan; Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan; Department of Psychology, University of California, Berkeley, Berkeley, CA 94704, United States.
| | - Hiromasa Takemura
- Center for Information and Neural Networks (CiNet), Advanced ICT Research Institute, National Institute of Information and Communications Technology, Suita 565-0871, Japan; Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan; Division of Sensory and Cognitive Brain Mapping, Department of System Neuroscience, National Institute for Physiological Sciences, Okazaki 444-8585, Japan; Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Hayama 240-0193, Japan.
| | - Kaoru Amano
- Center for Information and Neural Networks (CiNet), Advanced ICT Research Institute, National Institute of Information and Communications Technology, Suita 565-0871, Japan; Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan; Graduate School of Information Science and Technology, The University of Tokyo, Tokyo 113-8656, Japan
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7
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Berman S, Drori E, Mezer AA. Spatial profiles provide sensitive MRI measures of the midbrain micro- and macrostructure. Neuroimage 2022; 264:119660. [PMID: 36220534 DOI: 10.1016/j.neuroimage.2022.119660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/15/2022] [Accepted: 09/30/2022] [Indexed: 11/09/2022] Open
Abstract
The midbrain is the rostral-most part of the brainstem. It contains numerous nuclei and white matter tracts, which are involved in motor, auditory and visual processing, and changes in their structure and function have been associated with aging, as well as neurodegenerative disorders. Current tools for estimating midbrain subregions and their structure with MRI require high resolution and multi-parametric quantitative MRI measures. We propose an approach that relies on morphology to calculate profiles along the midbrain and show these profiles are sensitive to the underlying macrostructure of the midbrain. First, we show that the midbrain structure can be sampled, within subject space, along three main axes of the left and right midbrain, producing profiles that are similar across subjects. We use two data sets with different field strengths, that contain R1, R2* and QSM maps and show that the profiles are highly correlated both across subjects and between datasets. Next, we compare profiles of the midbrain that sample ROIs, and show that the profiles along the first two axes sample the midbrain in a way that reliably separates the main structures, i.e., the substantia nigra, the red nucleus, and periaqueductal gray. We further show that age differences which are localized to specific nuclei, are reflected in the profiles. Finally, we generalize the same approach to calculate midbrain profiles on a third clinically relevant dataset using HCP subjects, with metrics such as the diffusion tensor and semi-quantitative data such as T1w/T2w maps. Our results suggest that midbrain profiles, both of quantitative and semi-quantitative estimates are sensitive to the underlying macrostructure of the midbrain. The midbrain profiles are calculated in native space, and rely on simple measurements. We show that it is robust and can be easily expanded to different datasets, and as such we hope that it will be of great use to the community and to the study of the midbrain in particular.
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Affiliation(s)
- Shai Berman
- The Edmond and Lily Safra Center for Brain Science, the Hebrew University of Jerusalem, Israel; Mortimer B. Zuckerman Mind, Brain, Behavior Institute, Columbia University, New York, NY, United States.
| | - Elior Drori
- The Edmond and Lily Safra Center for Brain Science, the Hebrew University of Jerusalem, Israel
| | - Aviv A Mezer
- The Edmond and Lily Safra Center for Brain Science, the Hebrew University of Jerusalem, Israel
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8
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C Thomas D, Oros-Peusquens AM, Poot D, Shah NJ. Whole-Brain Water Content Mapping Using Super-Resolution Reconstruction with MRI Acquisition in 3 Orthogonal Orientations. Magn Reson Med 2022; 88:2117-2130. [PMID: 35861258 DOI: 10.1002/mrm.29377] [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: 09/20/2021] [Revised: 06/13/2022] [Accepted: 06/13/2022] [Indexed: 11/11/2022]
Abstract
PURPOSE Brain water content provides rich tissue contrast comparable to that of longitudinal relaxation time T1 , but mapping is usually performed at modest resolution. In particular, the slice thickness in 2D mapping methods is limited. Here, we combine super-resolution reconstruction techniques with a fast water content mapping method to acquire high and isotropic resolution (0.75 mm) water content maps at 3 Tesla. METHODS A high-resolution multi-echo gradient echo image is super-resolution-reconstructed from 3 low-resolution, orthogonal multi-echo gradient echo image acquisitions, followed by water content mapping. The mapping accuracy and SNR of the proposed method are assessed using numerical simulations, phantom studies, and in vivo data acquired from 6 healthy volunteers at 3 Tesla. A high-resolution acquisition with an established mapping method is used as a reference. RESULTS Whole-brain water content maps with 0.75 mm isotropic resolution are demonstrated. No bias in the water content values was seen following super-resolution reconstruction. In the in vivo experiments, a lower SD of the mean water content values was observed with the proposed method compared to the reference method. CONCLUSIONS Super-resolution reconstruction of multi-echo gradient echo data is demonstrated, enabling whole-brain water content mapping with high and isotropic resolution. The accuracy of the proposed method is shown using phantoms and 6 healthy volunteers and was found to be unchanged compared to the conventional acquisition. The proposed method could increase the sensitivity of water content mapping sufficiently to enable the detection of very small lesions, such as cortical lesions in multiple sclerosis.
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Affiliation(s)
- Dennis C Thomas
- Institute of Neuroscience and Medicine 4, Jülich, Germany.,Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | | | - Dirk Poot
- Department of Radiology and Nuclear medicine, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - N Jon Shah
- Institute of Neuroscience and Medicine 4, Jülich, Germany.,Institute of Neuroscience and Medicine 11, INM-11, JARA, Jülich, Germany.,JARA - BRAIN - Translational Medicine, Aachen, Germany.,Department of Neurology, RWTH Aachen University, Aachen, Germany
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9
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Repeated Sub-Concussive Impacts and the Negative Effects of Contact Sports on Cognition and Brain Integrity. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19127098. [PMID: 35742344 PMCID: PMC9222631 DOI: 10.3390/ijerph19127098] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 05/29/2022] [Accepted: 06/06/2022] [Indexed: 11/29/2022]
Abstract
Sports are yielding a wealth of benefits for cardiovascular fitness, for psychological resilience, and for cognition. The amount of practice, and the type of practiced sports, are of importance to obtain these benefits and avoid any side effects. This is especially important in the context of contact sports. Contact sports are not only known to be a major source of injuries of the musculoskeletal apparatus, they are also significantly related to concussion and sub-concussion. Sub-concussive head impacts accumulate throughout the active sports career, and thus can cause measurable deficits and changes to brain health. Emerging research in the area of cumulative sub-concussions in contact sports has revealed several associated markers of brain injury. For example, recent studies discovered that repeated headers in soccer not only cause measurable signs of cognitive impairment but are also related to a prolonged cortical silent period in transcranial magnetic stimulation measurements. Other cognitive and neuroimaging biomarkers are also pointing to adverse effects of heading. A range of fluid biomarkers completes the picture of cumulating effects of sub-concussive impacts. Those accumulating effects can cause significant cognitive impairment later in life of active contact sportswomen and men. The aim of this review is to highlight the current scientific evidence on the effects of repeated sub-concussive head impacts on contact sports athletes’ brains, identify the areas in need of further investigation, highlight the potential of advanced neuroscientific methods, and comment on the steps governing bodies have made to address this issue. We conclude that there are indeed neural and biofluid markers that can help better understand the effects of repeated sub-concussive head impacts and that some aspects of contact sports should be redefined, especially in situations where sub-concussive impacts and concussions can be minimized.
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10
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Hof S, Marcus C, Kuebart A, Schulz J, Truse R, Raupach A, Bauer I, Flögel U, Picker O, Herminghaus A, Temme S. A Toolbox to Investigate the Impact of Impaired Oxygen Delivery in Experimental Disease Models. Front Med (Lausanne) 2022; 9:869372. [PMID: 35652064 PMCID: PMC9149176 DOI: 10.3389/fmed.2022.869372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/25/2022] [Indexed: 12/29/2022] Open
Abstract
Impaired oxygen utilization is the underlying pathophysiological process in different shock states. Clinically most important are septic and hemorrhagic shock, which comprise more than 75% of all clinical cases of shock. Both forms lead to severe dysfunction of the microcirculation and the mitochondria that can cause or further aggravate tissue damage and inflammation. However, the detailed mechanisms of acute and long-term effects of impaired oxygen utilization are still elusive. Importantly, a defective oxygen exploitation can impact multiple organs simultaneously and organ damage can be aggravated due to intense organ cross-talk or the presence of a systemic inflammatory response. Complexity is further increased through a large heterogeneity in the human population, differences in genetics, age and gender, comorbidities or disease history. To gain a deeper understanding of the principles, mechanisms, interconnections and consequences of impaired oxygen delivery and utilization, interdisciplinary preclinical as well as clinical research is required. In this review, we provide a "tool-box" that covers widely used animal disease models for septic and hemorrhagic shock and methods to determine the structure and function of the microcirculation as well as mitochondrial function. Furthermore, we suggest magnetic resonance imaging as a multimodal imaging platform to noninvasively assess the consequences of impaired oxygen delivery on organ function, cell metabolism, alterations in tissue textures or inflammation. Combining structural and functional analyses of oxygen delivery and utilization in animal models with additional data obtained by multiparametric MRI-based techniques can help to unravel mechanisms underlying immediate effects as well as long-term consequences of impaired oxygen delivery on multiple organs and may narrow the gap between experimental preclinical research and the human patient.
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Affiliation(s)
- Stefan Hof
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Carsten Marcus
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Anne Kuebart
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Jan Schulz
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Richard Truse
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Annika Raupach
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Inge Bauer
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Ulrich Flögel
- Experimental Cardiovascular Imaging, Department of Molecular Cardiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Olaf Picker
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Anna Herminghaus
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Sebastian Temme
- Department of Anaesthesiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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11
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Shah NJ, Abbas Z, Ridder D, Zimmermann M, Oros-Peusquens AM. A Novel MRI-Based Quantitative Water Content Atlas of the Human Brain. Neuroimage 2022; 252:119014. [PMID: 35202813 DOI: 10.1016/j.neuroimage.2022.119014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/08/2022] [Accepted: 02/17/2022] [Indexed: 11/19/2022] Open
Abstract
The measurement of quantitative, tissue-specific MR properties, e.g., water content, longitudinal relaxation time (T1) and effective transverse relaxation time (T2*), using quantitative MRI at a clinical field strength (1.5 T to 3T) is a well-explored topic. However, none of the commonly used standard brain atlases, such as MNI or JHU, provide quantitative information. Within the framework of quantitative MRI of the brain, this work reports on the development of the first quantitative brain atlas for tissue water content at 3T. A methodology to create this quantitative atlas of in vivo brain water content based on healthy volunteers is presented, and preliminary, practical examples of its potential applications are also shown. Established methods for the fast and reliable measurement of the absolute water content were used to achieve high precision and accuracy. Water content and T2* were mapped based on two different methods: an intermediate-TR, two-point method and a long-TR, single-scan method. Twenty healthy subjects (age 25.3 ± 2.5 years) were examined with these quantitative imaging protocols. The images were normalised to MNI stereotactic coordinates, and water content atlases of healthy volunteers were created for each method and compared. Regions-of-interest were generated with the help of a standard MNI template, and water content values averaged across the ROIs were compared to water content values from the literature. Finally, in order to demonstrate the strength of quantitative MRI, water content maps from patients with pathological changes in the brain due to stroke, tumour (glioblastoma) and multiple sclerosis were voxel-wise compared to the healthy brain. The water content atlases were largely independent of the method used to acquire the individual water maps. Global grey matter and white matter water content values between the methods agreed with each other to within 0.5 %. The feasibility of detecting abnormal water content in the brains of patients based on comparison to a healthy brain water content atlas was demonstrated. In summary, the first quantitative water content brain atlas in vivo has been developed and a voxel-wise assessment of pathology-related changes in the brain water content has been performed. These results suggest that qMRI, in combination with a water content atlas, allows for a quantitative interpretation of changes due to disease and could be used for disease monitoring.
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Affiliation(s)
- N Jon Shah
- Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich GmbH, Juelich, Germany; Institute of Neuroscience and Medicine - 11, Forschungszentrum Juelich GmbH, Juelich, Germany; Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany; JARA - BRAIN - Translational Medicine, RWTH Aachen University, Aachen, Germany.
| | - Zaheer Abbas
- Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich GmbH, Juelich, Germany; Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Dominik Ridder
- Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich GmbH, Juelich, Germany
| | - Markus Zimmermann
- Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich GmbH, Juelich, Germany
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12
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Marino M, Cordero-Grande L, Mantini D, Ferrazzi G. Conductivity Tensor Imaging of the Human Brain Using Water Mapping Techniques. Front Neurosci 2021; 15:694645. [PMID: 34393709 PMCID: PMC8363203 DOI: 10.3389/fnins.2021.694645] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 07/14/2021] [Indexed: 11/13/2022] Open
Abstract
Conductivity tensor imaging (CTI) has been recently proposed to map the conductivity tensor in 3D using magnetic resonance imaging (MRI) at the frequency range of the brain at rest, i.e., low-frequencies. Conventional CTI mapping methods process the trans-receiver phase of the MRI signal using the MR electric properties tomography (MR-EPT) technique, which in turn involves the application of the Laplace operator. This results in CTI maps with a low signal-to-noise ratio (SNR), artifacts at tissue boundaries and a limited spatial resolution. In order to improve on these aspects, a methodology independent from the MR-EPT method is proposed. This relies on the strong assumption for which electrical conductivity is univocally pre-determined by water concentration. In particular, CTI maps are calculated by combining high-frequency conductivity derived from water maps and multi b-value diffusion tensor imaging (DTI) data. Following the implementation of a pipeline to optimize the pre-processing of diffusion data and the fitting routine of a multi-compartment diffusivity model, reconstructed conductivity images were evaluated in terms of the achieved spatial resolution in five healthy subjects scanned at rest. We found that the pre-processing of diffusion data and the optimization of the fitting procedure improve the quality of conductivity maps. We achieve reproducible measurements across healthy participants and, in particular, we report conductivity values across subjects of 0.55 ± 0.01Sm, 0.3 ± 0.01Sm and 2.15 ± 0.02Sm for gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF), respectively. By attaining an actual spatial resolution of the conductivity tensor close to 1 mm in-plane isotropic, partial volume effects are reduced leading to good discrimination of tissues with similar conductivity values, such as GM and WM. The application of the proposed framework may contribute to a better definition of the head tissue compartments in electroencephalograpy/magnetoencephalography (EEG/MEG) source imaging and be used as biomarker for assessing conductivity changes in pathological conditions, such as stroke and brain tumors.
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Affiliation(s)
- Marco Marino
- Research Center for Motor Control and Neuroplasticity, KU Leuven, Leuven, Belgium.,IRCCS San Camillo Hospital, Venice, Italy
| | - Lucilio Cordero-Grande
- Biomedical Image Technologies, ETSI Telecomunicación, Universidad Politécnica de Madrid and CIBER-BBN, Madrid, Spain
| | - Dante Mantini
- Research Center for Motor Control and Neuroplasticity, KU Leuven, Leuven, Belgium.,IRCCS San Camillo Hospital, Venice, Italy
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13
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Dzieciol K, Iordanishvili E, Abbas Z, Nahimi A, Winterdahl M, Shah NJ. A robust method for the detection of small changes in relaxation parameters and free water content in the vicinity of the substantia nigra in Parkinson's disease patients. PLoS One 2021; 16:e0247552. [PMID: 33626092 PMCID: PMC7904163 DOI: 10.1371/journal.pone.0247552] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 02/09/2021] [Indexed: 11/19/2022] Open
Abstract
Alterations in the substantia nigra are strongly associated with Parkinson's disease. However, due to low contrast and partial volume effects present in typical MRI images, the substantia nigra is not of sufficient size to obtain a reliable segmentation for region-of-interest based analysis. To combat this problem, the approach proposed here offers a method to investigate and reveal changes in quantitative MRI parameters in the vicinity of substantia nigra without any a priori delineation. This approach uses an alternative method of statistical, voxel-based analysis of quantitative maps and was tested on 18 patients and 15 healthy controls using a well-established, quantitative free water mapping protocol. It was possible to reveal the topology and the location of pathological changes in the substantia nigra and its vicinity. Moreover, a decrease in free water content, T1 and T2* in the vicinity of substantia nigra was indicated in the Parkinson's disease patients compared to the healthy controls. These findings reflect a disruption of grey matter and iron accumulation, which is known to lead to neurodegeneration. Consequently, the proposed method demonstrates an increased sensitivity for the detection of pathological changes-even in small regions-and can facilitate disease monitoring via quantitative MR parameters.
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Affiliation(s)
- Krzysztof Dzieciol
- Institute of Neuroscience and Medicine 4 (INM-4), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Elene Iordanishvili
- Institute of Neuroscience and Medicine 4 (INM-4), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Zaheer Abbas
- Institute of Neuroscience and Medicine 4 (INM-4), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Adjmal Nahimi
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Michael Winterdahl
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - N. Jon Shah
- Institute of Neuroscience and Medicine 4 (INM-4), Forschungszentrum Jülich GmbH, Jülich, Germany
- Institute of Neuroscience and Medicine 11 (INM-11), Forschungszentrum Jülich GmbH, Jülich, Germany
- Jülich Aachen Research Alliance (JARA-BRAIN)—Translational Medicine, Aachen, Germany
- Department of Neurology, RWTH Aachen University, Aachen, Germany
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14
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Abstract
γ-Aminobutyric acid (GABA) is a primary inhibitory neurotransmitter in the human brain. It has been shown that altered GABA concentration plays an important role in a variety of psychiatric and neurological disorders. The main purpose of this study was to propose a combination of PRESS and MEGA-PRESS acquisitions for absolute GABA quantification and to compare GABA estimations obtained using total choline (tCho), total creatine (tCr), and total N-acetyl aspartate (tNAA) as the internal concentration references with water referenced quantification. The second aim was to demonstrate the fitting approach of MEGA-PRESS spectra with QuasarX algorithm using a basis set of GABA, glutamate, glutamine, and NAA in vitro spectra. Thirteen volunteers were scanned with the MEGA-PRESS sequence at 3T. Interleaved water referencing was used for quantification, B0 drift correction and to update the carrier frequency of RF pulses in real time. Reference metabolite concentrations were acquired using a PRESS sequence with short TE (30 ms) and long TR (5000 ms). Absolute concentration were corrected for cerebrospinal fluid, gray and white matter water fractions and relaxation effects. Water referenced GABA estimations were significantly higher compared to the values obtained by metabolite references. We conclude that QuasarX algorithm together with the basis set of in vitro spectra improves reliability of GABA+ fitting. The proposed GABA quantification method with PRESS and MEGA-PRESS acquisitions enables the utilization of tCho, tCr, and tNAA as internal concentration references. The use of different concentration references have a good potential to improve the reliability of GABA estimation.
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15
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Gavdush AA, Chernomyrdin NV, Komandin GA, Dolganova IN, Nikitin PV, Musina GR, Katyba GM, Kucheryavenko AS, Reshetov IV, Potapov AA, Tuchin VV, Zaytsev KI. Terahertz dielectric spectroscopy of human brain gliomas and intact tissues ex vivo: double-Debye and double-overdamped-oscillator models of dielectric response. BIOMEDICAL OPTICS EXPRESS 2021; 12:69-83. [PMID: 33659071 PMCID: PMC7899500 DOI: 10.1364/boe.411025] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/25/2020] [Accepted: 11/30/2020] [Indexed: 05/07/2023]
Abstract
Terahertz (THz) technology offers novel opportunities in the intraoperative neurodiagnosis. Recently, the significant progress was achieved in the study of brain gliomas and intact tissues, highlighting a potential for THz technology in the intraoperative delineation of tumor margins. However, a lack of physical models describing the THz dielectric permittivity of healthy and pathological brain tissues restrains the further progress in this field. In the present work, the ex vivo THz dielectric response of human brain tissues was analyzed using relaxation models of complex dielectric permittivity. Dielectric response of tissues was parametrized by a pair of the Debye relaxators and a pair of the overdamped-oscillators - namely, the double-Debye (DD) and double-overdamped-oscillator (DO) models. Both models accurately reproduce the experimental curves for the intact tissues and the WHO Grades I-IV gliomas. While the DD model is more common for THz biophotonics, the DO model is more physically rigorous, since it satisfies the sum rule. In this way, the DO model and the sum rule were, then, applied to estimate the content of water in intact tissues and gliomas ex vivo. The observed results agreed well with the earlier-reported data, justifying water as a main endogenous label of brain tumors in the THz range. The developed models can be used to describe completely the THz-wave - human brain tissues interactions in the frameworks of classical electrodynamics, being quite important for further research and developments in THz neurodiagnosis of tumors.
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Affiliation(s)
- A A Gavdush
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
| | - N V Chernomyrdin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - G A Komandin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
| | - I N Dolganova
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
- Institute of Solid State Physics of the Russian Academy of Sciences, Chernogolovka, Russia
| | - P V Nikitin
- P.K. Anokhin Institute of Normal Physiology, Moscow, Russia
| | - G R Musina
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
| | - G M Katyba
- Institute of Solid State Physics of the Russian Academy of Sciences, Chernogolovka, Russia
| | - A S Kucheryavenko
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
- Institute of Solid State Physics of the Russian Academy of Sciences, Chernogolovka, Russia
| | - I V Reshetov
- Institute for Cluster Oncology, Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - A A Potapov
- Burdenko Neurosurgery Institute, Moscow, Russia
| | - V V Tuchin
- Saratov State University, Saratov, Russia
- Institute of Precision Mechanics and Control of the Russian Academy of Sciences, Saratov, Russia
- National Research Tomsk State University, Tomsk, Russia
| | - K I Zaytsev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow, Russia
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16
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Tian X, Lv Y, Fan Y, Wang Z, Yu B, Song C, Lu Q, Xi C, Pi L, Zhang X. Safety evaluation of mice exposed to 7.0-33.0 T high-static magnetic fields. J Magn Reson Imaging 2020; 53:1872-1884. [PMID: 33382516 DOI: 10.1002/jmri.27496] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 01/26/2023] Open
Abstract
Magnetic resonance imaging (MRI) of 7 T and higher can provide superior image resolution and capability. Clinical tests have been performed in 9.4 T MRI, and 21.1 T small-bore-size MRI has also been tested in rodents. Although the safety issue is a prerequisite for their future medical application, there are very few relevant studies for the safety of static magnetic fields (SMFs) of ≧20 T. The aim of this study was to assess the biological effects of 7.0-33.0 T SMFs in healthy adult mice. This was a prospective study, in which 104 healthy adult C57BL/6 mice were divided into control, sham control, and 7.0-33.0 T SMF-exposed groups.The sham control group and SMF group were handled identically, except for the electric current for producing SMF. A separate control group was placed outside the magnet and their data were used as normal range. After 1 h exposure, all mice were routinely fed for another 2 months while their body weight and food/water consumption were monitored. After 2 months, their complete blood count, blood biochemistry, key organ weight, and histomorphology were examined. All data are normally distributed. Differences between the sham and SMF-exposed groups were evaluated by unpaired t test. Most indicators did not show statistically significant changes or were still within the normal ranges, with only a few exceptions. For example, mono % in Group 2 (11.1 T) is 6.03 ± 1.43% while the normal range is 6.60-9.90% (p < 0.05). The cholesterol level in 33 T group is 3.38 ± 0.36 mmol/L while the normal range is 2.48-3.29 mmol/L (p < 0.05). The high-density lipoprotein cholesterol level in 33 T group is 2.54 ± 0.29 mmol/L while the normal reference range is 1.89-2.43 mmol/L (p < 0.01). Exposure to 7.0-33.0 T for 1 h did not have detrimental effects on normal adult mice. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1.
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Affiliation(s)
- Xiaofei Tian
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Yue Lv
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, China
| | - Yixiang Fan
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, China
| | - Ze Wang
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, China
| | - Biao Yu
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, China
| | - Chao Song
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, China
| | - Qingyou Lu
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, China.,Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, Hefei, China
| | - Chuanying Xi
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Li Pi
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Xin Zhang
- High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, China.,Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
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17
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Golub M, Neto Henriques R, Gouveia Nunes R. Free-water DTI estimates from single b-value data might seem plausible but must be interpreted with care. Magn Reson Med 2020; 85:2537-2551. [PMID: 33270935 DOI: 10.1002/mrm.28599] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/19/2020] [Accepted: 10/23/2020] [Indexed: 01/18/2023]
Abstract
PURPOSE Free-water elimination DTI (FWE-DTI) has been used widely to distinguish increases of free-water partial-volume effects from tissue's diffusion in healthy aging and degenerative diseases. Because the FWE-DTI fitting is only well-posed for multishell acquisitions, a regularized gradient descent (RGD) method was proposed to enable application to single-shell data, more common in the clinic. However, the validity of the RGD method has been poorly assessed. This study aims to quantify the specificity of FWE-DTI procedures on single-shell and multishell data. METHODS Different FWE-DTI fitting procedures were tested on an open-source in vivo diffusion data set and single-shell and multishell synthetic signals, including the RGD and standard nonlinear least-squares methods. Single-voxel simulations were carried out to compare initialization approaches. A multivoxel phantom simulation was performed to evaluate the effect of spatial regularization when comparing between methods. To test the algorithms' specificity, phantoms with two different types of lesions were simulated: with altered mean diffusivity or with modified free water. RESULTS Plausible parameter maps were obtained with RGD from single-shell in vivo data. The plausibility of these maps was shown to be determined by the initialization. Tests with simulated lesions inserted into the in vivo data revealed that the RGD approach cannot distinguish free water from tissue mean-diffusivity alterations, contrarily to the nonlinear least-squares algorithm. CONCLUSION The RGD FWE-DTI method has limited specificity; thus, its results from single-shell data should be carefully interpreted. When possible, multishell acquisitions and the nonlinear least-squares approach should be preferred instead.
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Affiliation(s)
- Marc Golub
- ISR-Lisboa/LARSyS and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | | | - Rita Gouveia Nunes
- ISR-Lisboa/LARSyS and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
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18
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Kullmann S, Abbas Z, Machann J, Shah NJ, Scheffler K, Birkenfeld AL, Häring HU, Fritsche A, Heni M, Preissl H. Investigating obesity-associated brain inflammation using quantitative water content mapping. J Neuroendocrinol 2020; 32:e12907. [PMID: 33025697 DOI: 10.1111/jne.12907] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/28/2020] [Accepted: 08/28/2020] [Indexed: 12/11/2022]
Abstract
There is growing evidence that obesity is associated with inflammation in the brain, which could contribute to the pathogenesis of obesity. In humans, it is challenging to detect brain inflammation in vivo. Recently, quantitative magnetic resonance imaging (qMRI) has emerged as a tool for characterising pathophysiological processes in the brain with reliable and reproducible measures. Proton density imaging provides quantitative assessment of the brain water content, which is affected in different pathologies, including inflammation. We enrolled 115 normal weight, overweight and obese men and women (body mass index [BMI] range 20.1-39.7 kg m-2 , age range 20-75 years, 60% men) to acquire cerebral water content mapping in vivo using MRI at 3 Tesla. We investigated potential associations between brain water content with anthropometric measures of obesity, body fat distribution and whole-body metabolism. No global changes in water content were associated with obesity. However, higher water content values in the cerebellum, limbic lobe and sub-lobular region were detected in participants with higher BMI, independent of age. More specifically, the dorsal striatum, hypothalamus, thalamus, fornix, anterior limb of the internal capsule and posterior thalamic radiation showed the strongest relationship with BMI, independent of age. In a subgroup with available measurements (n = 50), we identified visceral adipose tissue to be the strongest tested link between higher water content values and obesity. Individuals with metabolic syndrome had the highest water content values in the hypothalamus and the fornix. There is accumulating evidence that inflammation of the hypothalamus contributed to obesity-associated insulin resistance in that area. Whether brain inflammation is a cause or consequence of obesity in humans still needs to be investigated using a longitudinal study design. Using qMRI, we were able to detect marked water content changes in young and older obese adults, which is most likely the result of chronic low-grade inflammation.
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Affiliation(s)
- Stephanie Kullmann
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany
- Department of Internal Medicine IV, University of Tübingen, Tübingen, Germany
| | - Zaheer Abbas
- Institute of Neuroscience and Medicine - 4, Forschungszentrum Jülich GmbH, Jülich, Germany
- Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
| | - Jürgen Machann
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany
- Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University of Tübingen, Tübingen, Germany
| | - Nadim J Shah
- Institute of Neuroscience and Medicine - 4, Forschungszentrum Jülich GmbH, Jülich, Germany
- Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany
- Institute of Neuroscience and Medicine - 11, Forschungszentrum Jülich GmbH, Jülich, Germany
- JARA - BRAIN - Translational Medicine, RWTH Aachen University, Aachen, Germany
- Monash Biomedical Imaging, School of Psychological Sciences, Monash University, Melbourne, VIC, Australia
| | - Klaus Scheffler
- Department of High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Department of Biomedical Magnetic Resonance, University of Tübingen, Tübingen, Germany
| | - Andreas L Birkenfeld
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany
- Department of Internal Medicine IV, University of Tübingen, Tübingen, Germany
| | - Hans-Ulrich Häring
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany
- Department of Internal Medicine IV, University of Tübingen, Tübingen, Germany
| | - Andreas Fritsche
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany
- Department of Internal Medicine IV, University of Tübingen, Tübingen, Germany
| | - Martin Heni
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany
- Department of Internal Medicine IV, University of Tübingen, Tübingen, Germany
- Institute for Clinical Chemistry and Pathobiochemistry, University Hospital Tübingen, Tübingen, Germany
| | - Hubert Preissl
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany
- Department of Internal Medicine IV, University of Tübingen, Tübingen, Germany
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
- Department of Pharmacy and Biochemistry, Institute of Pharmaceutical Sciences, Eberhard Karls Universität Tübingen, Tübingen, Germany
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19
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Oleson S, Cox A, Liu Z, Sivasankar MP, Lu KH. In Vivo Magnetic Resonance Imaging of the Rat Vocal Folds After Systemic Dehydration and Rehydration. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2020; 63:135-142. [PMID: 31922926 PMCID: PMC7213491 DOI: 10.1044/2019_jslhr-19-00062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/27/2019] [Accepted: 09/12/2019] [Indexed: 06/10/2023]
Abstract
Objective Consuming less water (systemic dehydration) has long been thought to dehydrate the vocal folds. An in vivo, repeated measures study tested the assumption that systemic dehydration causes vocal fold dehydration. Proton density (PD)-weighted magnetic resonance imaging (MRI) of rat vocal folds was employed to investigate (a) whether varying magnitudes of systemic dehydration would dehydrate the vocal folds and (b) whether systemic rehydration would rehydrate the vocal folds. Method Male (n = 25) and female (n = 14) Sprague Dawley rats were imaged with 7T MRI, and normalized PD-weighted signal intensities were obtained at predehydration, following dehydration, and following rehydration. Animals were dehydrated to 1 of 3 levels by water withholding to induce body weight loss: mild (< 6% body weight loss), moderate (6%-10% body weight loss), and marked (> 10% body weight loss). Results There was a significant decrease in vocal fold signal intensities after moderate and marked dehydration (p < .0167). Rehydration increased the normalized signal intensity to predehydration levels for only the moderate group (p < .0167). Normalized signal intensity did not significantly change after mild dehydration or when the mildly dehydrated animals were rehydrated. Additionally, there were no significant differences in PD-weighted MRI normalized signal intensity between male and female rats (p > .05). Conclusion This study provides evidence supporting clinical voice recommendations for rehydration by increasing water intake after an acute, moderate systemic dehydration event. However, acute systemic dehydration of mild levels did not dehydrate the vocal folds as observed by PD-weighted MRI. Future programmatic research will focus on chronic, recurring systemic dehydration.
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Affiliation(s)
- Steven Oleson
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN
| | - Abigail Cox
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN
| | - Zhongming Liu
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN
| | - M. Preeti Sivasankar
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN
- Department of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, IN
| | - Kun-Han Lu
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN
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20
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Oros-Peusquens AM, Loução R, Abbas Z, Gras V, Zimmermann M, Shah NJ. A Single-Scan, Rapid Whole-Brain Protocol for Quantitative Water Content Mapping With Neurobiological Implications. Front Neurol 2019; 10:1333. [PMID: 31920951 PMCID: PMC6934004 DOI: 10.3389/fneur.2019.01333] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 12/02/2019] [Indexed: 12/16/2022] Open
Abstract
Water concentration is tightly regulated in the healthy human brain and changes only slightly with age and gender in healthy subjects. Consequently, changes in water content are important for the characterization of disease. MRI can be used to measure changes in brain water content, but as these changes are usually in the low percentage range, highly accurate and precise methods are required for detection. The method proposed here is based on a long-TR (10 s) multiple-echo gradient-echo measurement with an acquisition time of 7:21 min. Using such a long TR ensures that there is no T1 weighting, meaning that the image intensity at zero echo time is only proportional to the water content, the transmit field, and to the receive field. The receive and transmit corrections, which are increasingly large at higher field strengths and for highly segmented coil arrays, are multiplicative and can be approached heuristically using a bias field correction. The method was tested on 21 healthy volunteers at 3T field strength. Calibration using cerebral-spinal fluid values (~100% water content) resulted in mean values and standard deviations of the water content distribution in white matter and gray matter of 69.1% (1.7%) and 83.7% (1.2%), respectively. Measured distributions were coil-independent, as seen by using either a 12-channel receiver coil or a 32-channel receiver coil. In a test-retest investigation using 12 scans on one volunteer, the variation in the mean value of water content for different tissue types was ~0.3% and the mean voxel variability was ~1%. Robustness against reduced SNR was assessed by comparing results for 5 additional volunteers at 1.5T and 3T. Furthermore, water content distribution in gray matter is investigated and regional contrast reported for the first time. Clinical applicability is illustrated with data from one stroke patient and one brain tumor patient. It is anticipated that this fast, stable, easy-to-use, high-quality mapping method will facilitate routine quantitative MR imaging of water content.
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Affiliation(s)
| | - Ricardo Loução
- Institute of Neurosciences and Medicine 4 (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - Zaheer Abbas
- Institute of Neurosciences and Medicine 4 (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - Vincent Gras
- Institute of Neurosciences and Medicine 4 (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - Markus Zimmermann
- Institute of Neurosciences and Medicine 4 (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - N J Shah
- Institute of Neurosciences and Medicine 4 (INM-4), Forschungszentrum Jülich, Jülich, Germany.,Institute of Neurosciences and Medicine 11 (INM-11), JARA, Forschungszentrum Jülich, Jülich, Germany.,JARA - BRAIN - Translational Medicine, Aachen, Germany.,Department of Neurology, RWTH Aachen University, Aachen, Germany
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21
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Winterdahl M, Abbas Z, Noer O, Thomsen KL, Gras V, Nahimi A, Vilstrup H, Shah NJ, Dam G. Cerebral water content mapping in cirrhosis patients with and without manifest HE. Metab Brain Dis 2019; 34:1071-1076. [PMID: 31089866 DOI: 10.1007/s11011-019-00427-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 05/01/2019] [Indexed: 02/07/2023]
Abstract
Hepatic encephalopathy (HE) is a frequent and debilitating complication of cirrhosis and its pathogenesis is not definitively clarified. Recent hypotheses focus on the possible existence of low-grade cerebral edema due to accumulation of osmolytes secondary to hyperammonemia. In the present study we investigated increases in cerebral water content by a novel magnetic resonance impedance (MRI) technique in cirrhosis patients with and without clinically manifest HE. We used a 3 T MRI technique for quantitative cerebral water content mapping in nine cirrhosis patients with an episode of overt HE, ten cirrhosis patients who never suffered from HE, and ten healthy aged-matched controls. We tested for differences between groups by statistical non-parametric mapping (SnPM) for a voxel-based spatial evaluation. The patients with HE had significantly higher water content in white matter than the cirrhosis patients (0.6%), who in turn, had significantly higher content than the controls (1.7%). Although the global gray matter water content did not differ between the groups, the patients with HE had markedly higher thalamic water content than patients who never experienced HE (6.0% higher). We found increased white matter water content in cirrhosis patients, predominantly in those with manifest HE. This confirms the presence of increasing degrees of low-grade edema with exacerbation of pathology. The thalamic edema in manifest HE may lead to compromised basal ganglia-thalamo-cortical circuits, in accordance with the major clinical symptoms of HE. The identification of the thalamus as particularly inflicted in manifest HE is potentially relevant to the pathophysiology of HE.
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Affiliation(s)
- Michael Winterdahl
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Zaheer Abbas
- Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, 52425, Jülich, Germany
- Department of Neurology, RWTH Aachen University Clinic, Aachen, Germany
- JARA - Jülich Aachen Research Alliance, Aachen, Germany
| | - Ove Noer
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Karen Louise Thomsen
- Department of Hepatology & Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Adjmal Nahimi
- Department of Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark
| | - Hendrik Vilstrup
- Department of Hepatology & Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Nadim Joni Shah
- Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, 52425, Jülich, Germany
- Department of Neurology, RWTH Aachen University Clinic, Aachen, Germany
- JARA - Jülich Aachen Research Alliance, Aachen, Germany
| | - Gitte Dam
- Department of Hepatology & Gastroenterology, Aarhus University Hospital, Aarhus, Denmark.
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22
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Claeser R, Zimmermann M, Shah NJ. Sub-millimeter T 1 mapping of rapidly relaxing compartments with gradient delay corrected spiral TAPIR and compressed sensing at 3T. Magn Reson Med 2019; 82:1288-1300. [PMID: 31148282 DOI: 10.1002/mrm.27797] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 04/10/2019] [Accepted: 04/12/2019] [Indexed: 11/09/2022]
Abstract
PURPOSE The TAPIR sequence is an accurate and efficient method for T1 mapping. It combines a slice-interleaving Look-Locker read-out with an acquisition of multiple k-space lines in 1 shot. Whereas the acquisition of multiple lines per excitation increases imaging speed, the corresponding increase in TR and TE is detrimental to the T1 fitting performance. This is especially problematic for substances exhibiting rapid T2 * relaxation (e.g., myelin water). METHODS The T1 fitting performance of TAPIR is enhanced by using an interleaved spiral read-out with shorter TE and TR. Furthermore, an improvement to a method for fast gradient delay estimation is presented. Whereas previous methods assume the gradient delay to be stationary, the presented approach corrects the spiral k-space trajectory by using a polynomial fit of the measured gradient delays. RESULTS Gradient delay artifacts are largely eliminated, requiring very little additional scanning time. The sampling efficiency of the spiral read-out allows for a significant reduction of the acquisition time in comparison to Cartesian TAPIR. Spiral TAPIR enables the sampling of more slices and an accurate measurement of rapidly relaxing compartments. Over a wide T1 range (448-3115 ms), spiral TAPIR reduces the mean fitting error from -2.5% to -0.1%. Combining 50% undersampling with the shorter TR of spiral TAPIR, an increase in imaging speed by a factor of up to 3.3 was achieved. CONCLUSION Using a spiral read-out trajectory, the established TAPIR sequence enables measurement of rapidly relaxing T1 compartments, while improving T1 mapping performance and imaging speed.
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Affiliation(s)
- Robert Claeser
- Institute of Neuroscience and Medicine 4 (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - Markus Zimmermann
- Institute of Neuroscience and Medicine 4 (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - N Jon Shah
- Institute of Neuroscience and Medicine 4 (INM-4), Forschungszentrum Jülich, Jülich, Germany.,Institute of Neuroscience and Medicine 11 (INM-11), Forschungszentrum Jülich, Jülich, Germany.,Jülich Aachen Research Alliance (JARA-BRAIN), Translational Medicine, Aachen, Germany.,Department of Neurology, RWTH Aachen University, Aachen, Germany
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23
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Schall M, Zimmermann M, Iordanishvili E, Gu Y, Shah NJ, Oros-Peusquens AM. A 3D two-point method for whole-brain water content and relaxation time mapping: Comparison with gold standard methods. PLoS One 2018; 13:e0201013. [PMID: 30161125 PMCID: PMC6116981 DOI: 10.1371/journal.pone.0201013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 07/06/2018] [Indexed: 12/23/2022] Open
Abstract
Quantitative imaging of the human brain is of great interest in clinical research as it enables the identification of a range of MR biomarkers useful in diagnosis, treatment and prognosis of a wide spectrum of diseases. Here, a 3D two-point method for water content and relaxation time mapping is presented and compared to established gold standard methods. The method determines free water content, H2O, and the longitudinal relaxation time, T1, quantitatively from a two-point fit to the signal equation including corrections of the transmit and receive fields. In addition, the effective transverse relaxation time, T2*, is obtained from an exponential fit to the multi-echo signal train and its influence on H2O values is corrected. The phantom results obtained with the proposed method show good agreement for H2O and T1 values with known and spectroscopically measured values, respectively. The method is compared in vivo to already established gold standard quantitative methods. For H2O and T2* mapping, the 3D two-point results were compared to a measurement conducted with a multiple-echo GRE with long TR and T1 is compared to results from a Look-Locker method, TAPIR. In vivo results show good overall agreement between the methods, but some systematic deviations are present. Besides an expected dependence of T2* on voxel size, T1 values are systematically larger in the 3D approach than those obtained with the gold standard method. This behaviour might be due to imperfect spoiling, influencing each method differently. Results for H2O differ due to differences in the saturation of cerebrospinal fluid and partial volume effects. In addition, ground truth values of in vivo studies are unknown, even when comparing to in vivo gold standard methods. A detailed region-of-interest analysis for H2O and T1 matches well published literature values.
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Affiliation(s)
- Melissa Schall
- Institute of Neuroscience and Medicine 4 (INM-4), Research Centre Jülich, Jülich, Germany
| | - Markus Zimmermann
- Institute of Neuroscience and Medicine 4 (INM-4), Research Centre Jülich, Jülich, Germany
| | - Elene Iordanishvili
- Institute of Neuroscience and Medicine 4 (INM-4), Research Centre Jülich, Jülich, Germany
| | - Yun Gu
- Institute of Neuroscience and Medicine 4 (INM-4), Research Centre Jülich, Jülich, Germany
| | - N. Jon Shah
- Institute of Neuroscience and Medicine 4 (INM-4), Research Centre Jülich, Jülich, Germany
- Institute of Neuroscience and Medicine 11 (INM-11), Research Centre Jülich, Jülich, Germany
- Jülich Aachen Research Alliance (JARA-BRAIN)—TranslationalMedicine, Aachen, Germany
- Department of Neurology of the RWTH Aachen University, Aachen, Germany
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24
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Zimmermann M, Abbas Z, Dzieciol K, Shah NJ. Accelerated Parameter Mapping of Multiple-Echo Gradient-Echo Data Using Model-Based Iterative Reconstruction. IEEE TRANSACTIONS ON MEDICAL IMAGING 2018; 37:626-637. [PMID: 29408790 DOI: 10.1109/tmi.2017.2771504] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A new reconstruction method, coined MIRAGE, is presented for accurate, fast, and robust parameter mapping of multiple-echo gradient-echo (MEGE) imaging, the basis sequence of novel quantitative magnetic resonance imaging techniques such as water content and susceptibility mapping. Assuming that the temporal signal can be modeled as a sum of damped complex exponentials, MIRAGE performs model-based reconstruction of undersampled data by minimizing the rank of local Hankel matrices. It further incorporates multi-channel information and spatial prior knowledge. Finally, the parameter maps are estimated using nonlinear regression. Simulations and retrospective undersampling of phantom and in vivo data affirm robustness, e.g., to strong inhomogeneity of the static magnetic field and partial volume effects. MIRAGE is compared with a state-of-the-art compressed sensing method, -ESPIRiT. Parameter maps estimated from reconstructed data using MIRAGE are shown to be accurate, with the mean absolute error reduced by up to 50% for in vivo results. The proposed method has the potential to improve the diagnostic utility of quantitative imaging techniques that rely on MEGE data.
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25
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Lévy S, Guertin MC, Khatibi A, Mezer A, Martinu K, Chen JI, Stikov N, Rainville P, Cohen-Adad J. Test-retest reliability of myelin imaging in the human spinal cord: Measurement errors versus region- and aging-induced variations. PLoS One 2018; 13:e0189944. [PMID: 29293550 PMCID: PMC5749716 DOI: 10.1371/journal.pone.0189944] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 12/05/2017] [Indexed: 01/06/2023] Open
Abstract
PURPOSE To implement a statistical framework for assessing the precision of several quantitative MRI metrics sensitive to myelin in the human spinal cord: T1, Magnetization Transfer Ratio (MTR), saturation imposed by an off-resonance pulse (MTsat) and Macromolecular Tissue Volume (MTV). METHODS Thirty-three healthy subjects within two age groups (young, elderly) were scanned at 3T. Among them, 16 underwent the protocol twice to assess repeatability. Statistical reliability indexes such as the Minimal Detectable Change (MDC) were compared across metrics quantified within different cervical levels and white matter (WM) sub-regions. The differences between pathways and age groups were quantified and interpreted in context of the test-retest repeatability of the measurements. RESULTS The MDC was respectively 105.7ms, 2.77%, 0.37% and 4.08% for T1, MTR, MTsat and MTV when quantified over all WM, while the standard-deviation across subjects was 70.5ms, 1.34%, 0.20% and 2.44%. Even though particular WM regions did exhibit significant differences, these differences were on the same order as test-retest errors. No significant difference was found between age groups for all metrics. CONCLUSION While T1-based metrics (T1 and MTV) exhibited better reliability than MT-based measurements (MTR and MTsat), the observed differences between subjects or WM regions were comparable to (and often smaller than) the MDC. This makes it difficult to determine if observed changes are due to variations in myelin content, or simply due to measurement error. Measurement error remains a challenge in spinal cord myelin imaging, but this study provides statistical guidelines to standardize the field and make it possible to conduct large-scale multi-center studies.
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Affiliation(s)
- Simon Lévy
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
| | - Marie-Claude Guertin
- Montreal Health Innovations Coordinating Center (MHICC), Montreal Heart Institute, Montreal, QC, Canada
| | - Ali Khatibi
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
- Psychology Department, Bilkent University, Ankara, Turkey
- Interdisciplinary program in Neuroscience, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Aviv Mezer
- The Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Kristina Martinu
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
| | - Jen-I Chen
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
- Department of Stomatology, Faculty of Dentistry, Université de Montréal, Montreal, QC, Canada
| | - Nikola Stikov
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
- Montreal Heart Institute, Montreal, QC, Canada
| | - Pierre Rainville
- Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal (CRIUGM), Montréal, QC, Canada
- Department of Stomatology, Faculty of Dentistry, Université de Montréal, Montreal, QC, Canada
| | - Julien Cohen-Adad
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, QC, Canada
- Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada
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Sudhyadhom A. Determination of mean ionization potential using magnetic resonance imaging for the reduction of proton beam range uncertainties: theory and application. ACTA ACUST UNITED AC 2017; 62:8521-8535. [DOI: 10.1088/1361-6560/aa8d9e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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27
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Berman S, West KL, Does MD, Yeatman JD, Mezer AA. Evaluating g-ratio weighted changes in the corpus callosum as a function of age and sex. Neuroimage 2017; 182:304-313. [PMID: 28673882 DOI: 10.1016/j.neuroimage.2017.06.076] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 11/16/2022] Open
Abstract
Recent years have seen a growing interest in relating MRI measurements to the structural-biophysical properties of white matter fibers. The fiber g-ratio, defined as the ratio between the inner and outer radii of the axon myelin sheath, is an important structural property of white matter, affecting signal conduction. Recently proposed modeling methods that use a combination of quantitative-MRI signals, enable a measurement of the fiber g-ratio in vivo. Here we use an MRI-based g-ratio estimation to observe the variance of the g-ratio within the corpus callosum, and evaluate sex and age related differences. To estimate the g-ratio we used a model (Stikov et al., 2011; Duval et al., 2017) based on two different WM microstructure parameters: the relative amounts of myelin (myelin volume fraction, MVF) and fibers (fiber volume fraction, FVF) in a voxel. We derived the FVF from the fractional anisotropy (FA), and estimated the MVF by using the lipid and macromolecular tissue volume (MTV), calculated from the proton density (Mezer et al., 2013). In comparison to other methods of estimating the MVF, MTV represents a stable parameter with a straightforward route of acquisition. To establish our model, we first compared histological MVF measurements (West et al., 2016) with the MRI derived MTV. We then implemented our model on a large database of 92 subjects (44 males), aged 7 to 81, in order to evaluate age and sex related changes within the corpus callosum. Our results show that the MTV provides a good estimation of MVF for calculating g-ratio, and produced values from the corpus callosum that correspond to those found in animals ex vivo and are close to the theoretical optimum, as well as to published in vivo data. Our results demonstrate that the MTV derived g-ratio provides a simple and reliable in vivo g-ratio-weighted (GR*) measurement in humans. In agreement with theoretical predictions, and unlike other tissue parameters measured with MRI, the g-ratio estimations were found to be relatively stable with age, and we found no support for a significant sexual dimorphism with age.
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Affiliation(s)
- Shai Berman
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Kathryn L West
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - Mark D Does
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA
| | - Jason D Yeatman
- Institute for Learning & Brain Sciences and Department of Speech & Hearing Sciences, University of Washington, Seattle, WA, USA
| | - Aviv A Mezer
- The Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
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28
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Nguyen TD, Spincemaille P, Gauthier SA, Wang Y. Rapid whole brain myelin water content mapping without an external water standard at 1.5 T. Magn Reson Imaging 2017; 39:82-88. [DOI: 10.1016/j.mri.2016.12.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 12/20/2016] [Accepted: 12/21/2016] [Indexed: 12/18/2022]
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29
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Jutras JD, Wachowicz K, Gilbert G, De Zanche N. SNR efficiency of combined bipolar gradient echoes: Comparison of three-dimensional FLASH, MPRAGE, and multiparameter mapping with VFA-FLASH and MP2RAGE. Magn Reson Med 2016; 77:2186-2202. [DOI: 10.1002/mrm.26306] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/18/2016] [Accepted: 05/19/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Jean-David Jutras
- Department of Oncology; University of Alberta; Edmonton Alberta Canada
| | - Keith Wachowicz
- Department of Oncology; University of Alberta; Edmonton Alberta Canada
- Department of Medical Physics; Cross Cancer Institute; Edmonton Alberta Canada
| | - Guillaume Gilbert
- MR Clinical Science; Philips Healthcare Canada; Markham Ontario Canada
| | - Nicola De Zanche
- Department of Oncology; University of Alberta; Edmonton Alberta Canada
- Department of Medical Physics; Cross Cancer Institute; Edmonton Alberta Canada
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30
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van Gelderen P, Jiang X, Duyn JH. Rapid measurement of brain macromolecular proton fraction with transient saturation transfer MRI. Magn Reson Med 2016; 77:2174-2185. [PMID: 27342121 DOI: 10.1002/mrm.26304] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/18/2016] [Accepted: 05/19/2016] [Indexed: 01/08/2023]
Abstract
PURPOSE To develop an efficient MRI approach to estimate the nonwater proton fraction (f) in human brain. METHODS We implement a brief, efficient magnetization transfer (MT) pulse that selectively saturates the magnetization of the (semi-) solid protons, and monitor the transfer of this saturation to the water protons as a function of delay after saturation. RESULTS Analysis of the transient MT effect with two-pool model allowed robust extraction of f at both 3 and 7 T. This required estimating the longitudinal relaxation rate constant (R1,MP and R1,WP ) for both proton pools, which was achieved with the assumption of uniform R1,MP and R1,WP across brain tissues. Resulting values of f were approximately 50% higher than reported previously, which is partly attributed to MT-pulse efficiency and R1,MP being higher than assumed previously. CONCLUSION Experiments performed on human brain in vivo at 3 and 7 T demonstrate the ability of the method to robustly determine f in a scan time of approximately 5 min. Magn Reson Med 77:2174-2185, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Peter van Gelderen
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Xu Jiang
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Jeff H Duyn
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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Mezer A, Rokem A, Berman S, Hastie T, Wandell BA. Evaluating quantitative proton-density-mapping methods. Hum Brain Mapp 2016; 37:3623-35. [PMID: 27273015 DOI: 10.1002/hbm.23264] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 04/30/2016] [Accepted: 05/10/2016] [Indexed: 11/11/2022] Open
Abstract
Quantitative magnetic resonance imaging (qMRI) aims to quantify tissue parameters by eliminating instrumental bias. We describe qMRI theory, simulations, and software designed to estimate proton density (PD), the apparent local concentration of water protons in the living human brain. First, we show that, in the absence of noise, multichannel coil data contain enough information to separate PD and coil sensitivity, a limiting instrumental bias. Second, we show that, in the presence of noise, regularization by a constraint on the relationship between T1 and PD produces accurate coil sensitivity and PD maps. The ability to measure PD quantitatively has applications in the analysis of in-vivo human brain tissue and enables multisite comparisons between individuals and across instruments. Hum Brain Mapp 37:3623-3635, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Aviv Mezer
- The Hebrew University of Jerusalem, Edmond and Lily Safra Center for Brain Sciences, Jerusalem, Israel
| | - Ariel Rokem
- The University of Washington, eScience Institute, Seattle, WA, USA
| | - Shai Berman
- The Hebrew University of Jerusalem, Edmond and Lily Safra Center for Brain Sciences, Jerusalem, Israel
| | - Trevor Hastie
- Stanford University, Department of Psychology, Stanford, CA, USA
| | - Brian A Wandell
- Stanford University, Department of Psychology, Stanford, CA, USA.,Stanford University, Center for Cognitive and Neurobiological Imaging, Stanford, CA, USA
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Oeltzschner G, Butz M, Wickrath F, Wittsack HJ, Schnitzler A. Covert hepatic encephalopathy: elevated total glutathione and absence of brain water content changes. Metab Brain Dis 2016; 31:517-27. [PMID: 26563124 DOI: 10.1007/s11011-015-9760-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 11/06/2015] [Indexed: 01/20/2023]
Abstract
Recent pathophysiological models suggest that oxidative stress and hyperammonemia lead to a mild brain oedema in hepatic encephalopathy (HE). Glutathione (GSx) is a major cellular antioxidant and known to be involved in the interception of both. The aim of this work was to study total glutathione levels in covert HE (minimal HE and HE grade 1) and to investigate their relationship with local brain water content, levels of glutamine (Gln), myo-inositol (mI), neurotransmitter levels, critical flicker frequency (CFF), and blood ammonia. Proton magnetic resonance spectroscopy ((1)H MRS) data were analysed from visual and sensorimotor cortices of thirty patients with covert HE and 16 age-matched healthy controls. Total glutathione levels (GSx/Cr) were quantified with respect to creatine. Furthermore, quantitative MRI brain water content measures were evaluated. Data were tested for links with the CFF and blood ammonia. GSx/Cr was elevated in the visual (mHE) and sensorimotor (mHE, HE 1) MRS volumes and correlated with blood ammonia levels (both P < 0.001). It was further linked to Gln/Cr and mI/Cr (P < 0.01 in visual, P < 0.001 in sensorimotor) and to GABA/Cr (P < 0.01 in visual). Visual GSx/Cr correlated with brain water content in the thalamus, nucleus caudatus, and visual cortex (P < 0.01). Brain water measures did neither show group effects nor correlations with CFF or blood ammonia. Elevated total glutathione levels in covert HE (< HE 2) correlate with blood ammonia and may be a regional-specific reaction to hyperammonemia and oxidative stress. Brain water content is locally linked to visual glutathione levels, but appears not to be associated with changes of clinical parameters. This might suggest that cerebral oedema is only marginally responsible for the symptoms of covert HE.
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Affiliation(s)
- Georg Oeltzschner
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, D-40225, Düsseldorf, Germany.
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, D-40225, Düsseldorf, Germany.
| | - Markus Butz
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, D-40225, Düsseldorf, Germany
| | - Frithjof Wickrath
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, D-40225, Düsseldorf, Germany
| | - Hans-Jörg Wittsack
- Department of Diagnostic and Interventional Radiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, D-40225, Düsseldorf, Germany
| | - Alfons Schnitzler
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, D-40225, Düsseldorf, Germany
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Tardif CL, Gauthier CJ, Steele CJ, Bazin PL, Schäfer A, Schaefer A, Turner R, Villringer A. Advanced MRI techniques to improve our understanding of experience-induced neuroplasticity. Neuroimage 2016; 131:55-72. [DOI: 10.1016/j.neuroimage.2015.08.047] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/18/2015] [Accepted: 08/20/2015] [Indexed: 12/13/2022] Open
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Measuring water content using T2 relaxation at 3T: Phantom validations and simulations. Magn Reson Imaging 2016; 34:246-51. [DOI: 10.1016/j.mri.2015.11.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 07/23/2015] [Accepted: 11/29/2015] [Indexed: 12/14/2022]
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Michel E, Hernandez D, Lee SY. Electrical conductivity and permittivity maps of brain tissues derived from water content based on T 1 -weighted acquisition. Magn Reson Med 2016; 77:1094-1103. [PMID: 26946979 DOI: 10.1002/mrm.26193] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 01/15/2016] [Accepted: 02/10/2016] [Indexed: 12/12/2022]
Abstract
PURPOSE To develop an electrical properties tomography (EPT) technique that can provide in vivo electrical conductivity and permittivity images of biological tissue without performing complex-valued radiofrequency field measurements. THEORY AND METHODS Electrical conductivity and permittivity images are modeled as a monotonic function of tissues' water content (W) under the principle of Maxwell's mixture theory. Water content maps are estimated from two spin-echo images having different repetition times (TRs). For the modeling functions, physically measured parameters (electrical properties, water content, and T1 ) of brain cerebrospinal fluid (CSF), gray matter, and white matter are used as landmark literature references. The formulations are validated by a developed electrolyte-protein phantom and by human brain studies at 3 Tesla (T). RESULTS The electrical properties (EPs) of the phantom estimated by the proposed method match well with the values measured on the bench. The conductivity and permittivity maps from all experiments show uncompromised spatial resolution without boundary artifacts and higher contrast when compared with water content maps. CONCLUSIONS Human brain and phantom EP images suggest that water content is a dominating factor in determining the electrical properties of tissues. Despite possible literature inaccuracies, the proposed method offers EP maps that can provide complementary information to current approaches, to facilitate EPT scans in clinical applications. Magn Reson Med 77:1094-1103, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Eric Michel
- Department of Biomedical Engineering, Kyung Hee University, Yongin, Korea
| | - Daniel Hernandez
- Department of Biomedical Engineering, Kyung Hee University, Yongin, Korea
| | - Soo Yeol Lee
- Department of Biomedical Engineering, Kyung Hee University, Yongin, Korea
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Warntjes M, Engström M, Tisell A, Lundberg P. Modeling the Presence of Myelin and Edema in the Brain Based on Multi-Parametric Quantitative MRI. Front Neurol 2016; 7:16. [PMID: 26925030 PMCID: PMC4756127 DOI: 10.3389/fneur.2016.00016] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 02/02/2016] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to present a model that uses multi-parametric quantitative MRI to estimate the presence of myelin and edema in the brain. The model relates simultaneous measurement of R1 and R2 relaxation rates and proton density to four partial volume compartments, consisting of myelin partial volume, cellular partial volume, free water partial volume, and excess parenchymal water partial volume. The model parameters were obtained using spatially normalized brain images of a group of 20 healthy controls. The pathological brain was modeled in terms of the reduction of myelin content and presence of excess parenchymal water, which indicates the degree of edema. The method was tested on spatially normalized brain images of a group of 20 age-matched multiple sclerosis (MS) patients. Clear differences were observed with respect to the healthy controls: the MS group had a 79 mL smaller brain volume (1069 vs. 1148 mL), a 38 mL smaller myelin volume (119 vs. 157 mL), and a 21 mL larger excess parenchymal water volume (78 vs. 57 mL). Template regions of interest of various brain structures indicated that the myelin partial volume in the MS group was 1.6 ± 1.5% lower for gray matter (GM) structures and 2.8 ± 1.0% lower for white matter (WM) structures. The excess parenchymal water partial volume was 9 ± 10% larger for GM and 5 ± 2% larger for WM. Manually placed ROIs indicated that the results using the template ROIs may have suffered from loss of anatomical detail due to the spatial normalization process. Examples of the application of the method on high-resolution images are provided for three individual subjects: a 45-year-old healthy subject, a 72-year-old healthy subject, and a 45-year-old MS patient. The observed results agreed with the expected behavior considering both age and disease. In conclusion, the proposed model may provide clinically important parameters, such as the total brain volume, degree of myelination, and degree of edema, based on a single qMRI acquisition with a clinically acceptable scan time.
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Affiliation(s)
- Marcel Warntjes
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Maria Engström
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Radiology, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Anders Tisell
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Peter Lundberg
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; Radiation Physics, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
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van Gelderen P, Jiang X, Duyn JH. Effects of magnetization transfer on T1 contrast in human brain white matter. Neuroimage 2015; 128:85-95. [PMID: 26724780 DOI: 10.1016/j.neuroimage.2015.12.032] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 12/17/2015] [Accepted: 12/20/2015] [Indexed: 11/17/2022] Open
Abstract
MRI based on T1 relaxation contrast is increasingly being used to study brain morphology and myelination. Although it provides for excellent distinction between the major tissue types of gray matter, white matter, and CSF, reproducible quantification of T1 relaxation rates is difficult due to the complexity of the contrast mechanism and dependence on experimental details. In this work, we perform simulations and inversion-recovery MRI measurements at 3T and 7T to show that substantial measurement variability results from unintended and uncontrolled perturbation of the magnetization of MRI-invisible (1)H protons of lipids and macromolecules. This results in bi-exponential relaxation, with a fast component whose relative contribution under practical conditions can reach 20%. This phenomenon can strongly affect apparent relaxation rates, affect contrast between tissue types, and result in contrast variations over the brain. Based on this novel understanding, ways are proposed to minimize this experimental variability and its effect on T1 contrast, quantification accuracy and reproducibility.
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Affiliation(s)
- Peter van Gelderen
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xu Jiang
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeff H Duyn
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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Utility of texture analysis for quantifying hepatic fibrosis on proton density MRI. J Magn Reson Imaging 2015; 42:1259-65. [DOI: 10.1002/jmri.24898] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Accepted: 03/11/2015] [Indexed: 12/31/2022] Open
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Reetz K, Abbas Z, Costa AS, Gras V, Tiffin-Richards F, Mirzazade S, Holschbach B, Frank RD, Vassiliadou A, Krüger T, Eitner F, Gross T, Schulz JB, Floege J, Shah NJ. Increased cerebral water content in hemodialysis patients. PLoS One 2015; 10:e0122188. [PMID: 25826269 PMCID: PMC4380497 DOI: 10.1371/journal.pone.0122188] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 02/10/2015] [Indexed: 12/27/2022] Open
Abstract
Little information is available on the impact of hemodialysis on cerebral water homeostasis and its distribution in chronic kidney disease. We used a neuropsychological test battery, structural magnetic resonance imaging (MRI) and a novel technique for quantitative measurement of localized water content using 3T MRI to investigate ten hemodialysis patients (HD) on a dialysis-free day and after hemodialysis (2.4±2.2 hours), and a matched healthy control group with the same time interval. Neuropsychological testing revealed mainly attentional and executive cognitive dysfunction in HD. Voxel-based-morphometry showed only marginal alterations in the right inferior medial temporal lobe white matter in HD compared to controls. Marked increases in global brain water content were found in the white matter, specifically in parietal areas, in HD patients compared to controls. Although the global water content in the gray matter did not differ between the two groups, regional increases of brain water content in particular in parieto-temporal gray matter areas were observed in HD patients. No relevant brain hydration changes were revealed before and after hemodialysis. Whereas longer duration of dialysis vintage was associated with increased water content in parieto-temporal-occipital regions, lower intradialytic weight changes were negatively correlated with brain water content in these areas in HD patients. Worse cognitive performance on an attention task correlated with increased hydration in frontal white matter. In conclusion, long-term HD is associated with altered brain tissue water homeostasis mainly in parietal white matter regions, whereas the attentional domain in the cognitive dysfunction profile in HD could be linked to increased frontal white matter water content.
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Affiliation(s)
- Kathrin Reetz
- Department of Neurology, RWTH Aachen University Hospital, Germany
- Institute of Neuroscience and Medicine (INM-4), Research Centre Jülich GmbH, Jülich, Germany
- Jülich Aachen Research Alliance (JARA)—Translational Brain Medicine, Jülich and Aachen, Germany
- * E-mail:
| | - Zaheer Abbas
- Department of Neurology, RWTH Aachen University Hospital, Germany
- Institute of Neuroscience and Medicine (INM-4), Research Centre Jülich GmbH, Jülich, Germany
- Jülich Aachen Research Alliance (JARA)—Translational Brain Medicine, Jülich and Aachen, Germany
| | - Ana Sofia Costa
- Department of Neurology, RWTH Aachen University Hospital, Germany
- Jülich Aachen Research Alliance (JARA)—Translational Brain Medicine, Jülich and Aachen, Germany
| | - Vincent Gras
- Institute of Neuroscience and Medicine (INM-4), Research Centre Jülich GmbH, Jülich, Germany
| | - Frances Tiffin-Richards
- Department of Neurology, RWTH Aachen University Hospital, Germany
- Jülich Aachen Research Alliance (JARA)—Translational Brain Medicine, Jülich and Aachen, Germany
| | - Shahram Mirzazade
- Department of Neurology, RWTH Aachen University Hospital, Germany
- Institute of Neuroscience and Medicine (INM-4), Research Centre Jülich GmbH, Jülich, Germany
- Jülich Aachen Research Alliance (JARA)—Translational Brain Medicine, Jülich and Aachen, Germany
| | - Bernhard Holschbach
- KfH Kuratorium für Dialyse und Nierentransplantation e.V., Stolberg, Germany
| | - Rolf Dario Frank
- Department of Internal Medicine, St.-Antonius-Hospital Eschweiler, Eschweiler, Germany
| | | | - Thilo Krüger
- Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany
| | - Frank Eitner
- Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany
| | - Theresa Gross
- Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany
| | - Jörg Bernhard Schulz
- Department of Neurology, RWTH Aachen University Hospital, Germany
- Jülich Aachen Research Alliance (JARA)—Translational Brain Medicine, Jülich and Aachen, Germany
| | - Jürgen Floege
- Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany
| | - Nadim Jon Shah
- Department of Neurology, RWTH Aachen University Hospital, Germany
- Institute of Neuroscience and Medicine (INM-4), Research Centre Jülich GmbH, Jülich, Germany
- Jülich Aachen Research Alliance (JARA)—Translational Brain Medicine, Jülich and Aachen, Germany
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