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Liu S, Luo X, Chong JSX, Jiaerken Y, Youn SH, Zhang M, Zhou JH. Brain structure, amyloid, and behavioral features for predicting clinical progression in subjective cognitive decline. Hum Brain Mapp 2024; 45:e26765. [PMID: 38958401 PMCID: PMC11220833 DOI: 10.1002/hbm.26765] [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: 10/09/2023] [Revised: 05/28/2024] [Accepted: 06/10/2024] [Indexed: 07/04/2024] Open
Abstract
As a potential preclinical stage of Alzheimer's dementia, subjective cognitive decline (SCD) reveals a higher risk of future cognitive decline and conversion to dementia. However, it has not been clear whether SCD status increases the clinical progression of older adults in the context of amyloid deposition, cerebrovascular disease (CeVD), and psychiatric symptoms. We identified 99 normal controls (NC), 15 SCD individuals who developed mild cognitive impairment in the next 2 years (P-SCD), and 54 SCD individuals who did not (S-SCD) from ADNI database with both baseline and 2-year follow-up data. Total white matter hyperintensity (WMH), WMH in deep (DWMH) and periventricular (PWMH) regions, and voxel-wise grey matter volumes were compared among groups. Furthermore, using structural equation modelling method, we constructed path models to explore SCD-related brain changes longitudinally and to determine whether baseline SCD status, age, and depressive symptoms affect participants' clinical outcomes. Both SCD groups showed higher baseline amyloid PET SUVR, baseline PWMH volumes, and larger increase of PWMH volumes over time than NC. In contrast, only P-SCD had higher baseline DWMH volumes and larger increase of DWMH volumes over time than NC. No longitudinal differences in grey matter volume and amyloid was observed among NC, S-SCD, and P-SCD. Our path models demonstrated that SCD status contributed to future WMH progression. Further, baseline SCD status increases the risk of future cognitive decline, mediated by PWMH; baseline depressive symptoms directly contribute to clinical outcomes. In conclusion, both S-SCD and P-SCD exhibited more severe CeVD than NC. The CeVD burden increase was more pronounced in P-SCD. In contrast with the direct association of depressive symptoms with dementia severity progression, the effects of SCD status on future cognitive decline may manifest via CeVD pathologies. Our work highlights the importance of multi-modal longitudinal designs in understanding the SCD trajectory heterogeneity, paving the way for stratification and early intervention in the preclinical stage. PRACTITIONER POINTS: Both S-SCD and P-SCD exhibited more severe CeVD at baseline and a larger increase of CeVD burden compared to NC, while the burden was more pronounced in P-SCD. Baseline SCD status increases the risk of future PWMH and DWMH volume accumulation, mediated by baseline PWMH and DWMH volumes, respectively. Baseline SCD status increases the risk of future cognitive decline, mediated by baseline PWMH, while baseline depression status directly contributes to clinical outcome.
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Grants
- U01 AG024904 NIA NIH HHS
- W81XWH-12-2-0012 DoD Alzheimer's Disease Neuroimaging Initiative (Department of Defense)
- A20G8b0102 Research, Innovation and Enterprise (RIE) 2020 Advanced Manufacturing and Engineering (AME) Programmatic Fund (Agency for Science, Technology and Research (A*STAR), Singapore)
- NMRC/OFLCG19May-0035 National Medical Research Council, Singapore
- NMRC/CIRG/1485/2018 National Medical Research Council, Singapore
- NMRC/CSA-SI/0007/2016 National Medical Research Council, Singapore
- NMRC/MOH-00707-01 National Medical Research Council, Singapore
- NMRC/CG/435M009/2017-NUH/NUHS National Medical Research Council, Singapore
- CIRG21nov-0007 National Medical Research Council, Singapore
- HLCA23Feb-0004 National Medical Research Council, Singapore
- Yong Loo Lin School of Medicine Research Core Funding (National University of Singapore, Singapore)
- 82271936 National Natural Science Foundation of China
- 2022ZQ057 Zhejiang Provincial Administration of Traditional Chinese Medicine - Youth Talent Fund Project
- MOE-T2EP40120-0007 Ministry of Education, Singapore
- T2EP2-0223-0025 Ministry of Education, Singapore
- MOE-T2EP20220-0001 Ministry of Education, Singapore
- Alzheimer's Disease Neuroimaging Initiative (National Institutes of Health)
- DoD Alzheimer's Disease Neuroimaging Initiative (Department of Defense)
- National Medical Research Council, Singapore
- National Natural Science Foundation of China
- Ministry of Education, Singapore
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Affiliation(s)
- Siwei Liu
- Centre for Sleep and CognitionCentre for Translational Magnetic Resonance Research, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
- Human Potential Translational Research ProgramDepartment of MedicineNational University of SingaporeSingaporeSingapore
| | - Xiao Luo
- Department of Radiology, Second Affiliated HospitalZhejiang University School of MedicineHangzhouChina
| | - Joanna Su Xian Chong
- Centre for Sleep and CognitionCentre for Translational Magnetic Resonance Research, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
- Human Potential Translational Research ProgramDepartment of MedicineNational University of SingaporeSingaporeSingapore
| | - Yeerfan Jiaerken
- Department of Radiology, Second Affiliated HospitalZhejiang University School of MedicineHangzhouChina
| | - Shim Hee Youn
- Centre for Sleep and CognitionCentre for Translational Magnetic Resonance Research, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
- Human Potential Translational Research ProgramDepartment of MedicineNational University of SingaporeSingaporeSingapore
| | - Minming Zhang
- Department of Radiology, Second Affiliated HospitalZhejiang University School of MedicineHangzhouChina
| | - Juan Helen Zhou
- Centre for Sleep and CognitionCentre for Translational Magnetic Resonance Research, Yong Loo Lin School of MedicineNational University of SingaporeSingaporeSingapore
- Human Potential Translational Research ProgramDepartment of MedicineNational University of SingaporeSingaporeSingapore
- Department of Electrical and Computer EngineeringIntegrative Sciences and Engineering Programme (ISEP), NUS Graduate SchoolNational University of SingaporeSingaporeSingapore
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Middlebrooks EH, Patel V, Zhou X, Straub S, Murray JV, Agarwal AK, Okromelidze L, Singh RB, Lopez Chiriboga AS, Westerhold EM, Gupta V, Sandhu SJS, Marin Collazo IV, Tao S. 7 T Lesion-Attenuated Magnetization-Prepared Gradient Echo Acquisition for Detection of Posterior Fossa Demyelinating Lesions in Multiple Sclerosis. Invest Radiol 2024; 59:513-518. [PMID: 38193790 DOI: 10.1097/rli.0000000000001050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
OBJECTIVES Detection of infratentorial demyelinating lesions in multiple sclerosis (MS) presents a challenge in magnetic resonance imaging (MRI), a difficulty that is further heightened in 7 T MRI. This study aimed to assess the efficacy of a novel MRI approach, lesion-attenuated magnetization-prepared gradient echo acquisition (LAMA), for detecting demyelinating lesions within the posterior fossa and upper cervical spine on 7 T MRI and contrast its performance with conventional double-inversion recovery (DIR) and T2-weighted turbo spin echo sequences. MATERIALS AND METHODS We conducted a retrospective cross-sectional study in 42 patients with a confirmed diagnosis of MS. All patients had 7 T MRI that incorporated LAMA, 3D DIR, and 2D T2-weighted turbo spin echo sequences. Three readers assessed lesion count in the brainstem, cerebellum, and upper cervical spinal cord using both DIR and T2-weighted images in one session. In a separate session, LAMA was analyzed alone. Contrast-to-noise ratio was also compared between LAMA and the conventional sequences. Lesion counts between methods were assessed using nonparametric Wilcoxon signed rank test. Interrater agreement in lesion detection was estimated by intraclass correlation coefficients. RESULTS LAMA identified a significantly greater number of lesions than DIR + T2 (mean 6.4 vs 3.0; P < 0.001). LAMA also exhibited better interrater agreement (intraclass correlation coefficient [95% confidence interval], 0.75 [0.41-0.88] vs 0.61 [0.35-0.78]). The contrast-to-noise ratio for LAMA (3.7 ± 0.9) significantly exceeded that of DIR (1.94 ± 0.7) and T2 (1.2 ± 0.7) (all P 's < 0.001). In cases with no lesions detected using DIR + T2, at least 1 lesion was identified in 83.3% with LAMA. Across all analyzed brain regions, LAMA consistently detected more lesions than DIR + T2. CONCLUSIONS LAMA significantly improves the detection of infratentorial demyelinating lesions in MS patients compared with traditional methods. Integrating LAMA with standard magnetization-prepared 2 rapid acquisition gradient echo acquisition provides a valuable tool for accurately characterizing the extent of MS disease.
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Affiliation(s)
- Erik H Middlebrooks
- From the Department of Radiology, Mayo Clinic, Jacksonville, FL (E.H.M., V.P., X.Z., S.S., J.V.M.J., A.K.A., L.O., R.B.S., E.M.W., V.G., S.J.S.S., S.T.); and Department of Neurology, Mayo Clinic, Jacksonville, FL (A.S.L.C., I.V.M.)
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Uher D, Drenthen GS, Poser BA, Hofman PAM, Wagner LG, van Lanen RHGJ, Hoeberigs CM, Colon AJ, Schijns OEMG, Jansen JFA, Backes WH. DeepFLAIR: A neural network approach to mitigate signal and contrast loss in temporal lobes at 7 Tesla FLAIR images. Magn Reson Imaging 2024; 110:57-68. [PMID: 38621552 DOI: 10.1016/j.mri.2024.04.013] [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: 01/16/2024] [Revised: 04/04/2024] [Accepted: 04/10/2024] [Indexed: 04/17/2024]
Abstract
BACKGROUND AND PURPOSE Higher magnetic field strength introduces stronger magnetic field inhomogeneities in the brain, especially within temporal lobes, leading to image artifacts. Particularly, T2-weighted fluid-attenuated inversion recovery (FLAIR) images can be affected by these artifacts. Here, we aimed to improve the FLAIR image quality in temporal lobe regions through image processing of multiple contrast images via machine learning using a neural network. METHODS Thirteen drug-resistant MR-negative epilepsy patients (age 29.2 ± 9.4y, 5 females) were scanned on a 7 T MRI scanner. Magnetization-prepared (MP2RAGE) and saturation-prepared with 2 rapid gradient echoes, multi-echo gradient echo with four echo times, and the FLAIR sequence were acquired. A voxel-wise neural network was trained on extratemporal-lobe voxels from the acquired structural scans to generate a new FLAIR-like image (i.e., deepFLAIR) with reduced temporal lobe inhomogeneities. The deepFLAIR was evaluated in temporal lobes through signal-to-noise (SNR), contrast-to-noise (CNR) ratio, the sharpness of the gray-white matter boundary and joint-histogram analysis. Saliency mapping demonstrated the importance of each input image per voxel. RESULTS SNR and CNR in both gray and white matter were significantly increased (p < 0.05) in the deepFLAIR's temporal ROIs, compared to the FLAIR. The gray-white matter boundary sharpness was either preserved or improved in 10/13 right-sided temporal regions and was found significantly increased in the ROIs. Multiple image contrasts were influential for the deepFLAIR reconstruction with the MP2RAGE second inversion image being the most important. CONCLUSIONS The deepFLAIR network showed promise to restore the FLAIR signal and reduce contrast attenuation in temporal lobe areas. This may yield a valuable tool, especially when artifact-free FLAIR images are not available.
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Affiliation(s)
- Daniel Uher
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre, Maastricht, the Netherlands; Mental Health and Neuroscience Institute (MHeNs), Maastricht University, Maastricht, the Netherlands; Department of Neurosurgery, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Gerhard S Drenthen
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre, Maastricht, the Netherlands; Mental Health and Neuroscience Institute (MHeNs), Maastricht University, Maastricht, the Netherlands
| | - Benedikt A Poser
- Faculty of Psychology and Neuroscience (FPN), Maastricht University, the Netherlands
| | - Paul A M Hofman
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre, Maastricht, the Netherlands; Academic Center for Epileptology, Kempenhaeghe and Maastricht University Medical Centre, Heeze/Maastricht, the Netherlands
| | - Louis G Wagner
- Academic Center for Epileptology, Kempenhaeghe and Maastricht University Medical Centre, Heeze/Maastricht, the Netherlands
| | - Rick H G J van Lanen
- Mental Health and Neuroscience Institute (MHeNs), Maastricht University, Maastricht, the Netherlands; Department of Neurosurgery, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Christianne M Hoeberigs
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre, Maastricht, the Netherlands; Academic Center for Epileptology, Kempenhaeghe and Maastricht University Medical Centre, Heeze/Maastricht, the Netherlands
| | - Albert J Colon
- Academic Center for Epileptology, Kempenhaeghe and Maastricht University Medical Centre, Heeze/Maastricht, the Netherlands; Department of Epileptology, CHU-Martinique, Fort-de-France, France
| | - Olaf E M G Schijns
- Mental Health and Neuroscience Institute (MHeNs), Maastricht University, Maastricht, the Netherlands; Department of Neurosurgery, Maastricht University Medical Center, Maastricht, the Netherlands; Academic Center for Epileptology, Kempenhaeghe and Maastricht University Medical Centre, Heeze/Maastricht, the Netherlands
| | - Jacobus F A Jansen
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre, Maastricht, the Netherlands; Mental Health and Neuroscience Institute (MHeNs), Maastricht University, Maastricht, the Netherlands; Academic Center for Epileptology, Kempenhaeghe and Maastricht University Medical Centre, Heeze/Maastricht, the Netherlands; Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Walter H Backes
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Centre, Maastricht, the Netherlands; Mental Health and Neuroscience Institute (MHeNs), Maastricht University, Maastricht, the Netherlands; Cardiovascular Diseases Institute (CARIM), Maastricht University, Maastricht, the Netherlands.
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Donnay C, Dieckhaus H, Tsagkas C, Gaitán MI, Beck ES, Mullins A, Reich DS, Nair G. Pseudo-Label Assisted nnU-Net enables automatic segmentation of 7T MRI from a single acquisition. FRONTIERS IN NEUROIMAGING 2023; 2:1252261. [PMID: 38107773 PMCID: PMC10722186 DOI: 10.3389/fnimg.2023.1252261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 11/06/2023] [Indexed: 12/19/2023]
Abstract
Introduction Automatic whole brain and lesion segmentation at 7T presents challenges, primarily from bias fields, susceptibility artifacts including distortions, and registration errors. Here, we sought to use deep learning algorithms (D/L) to do both skull stripping and whole brain segmentation on multiple imaging contrasts generated in a single Magnetization Prepared 2 Rapid Acquisition Gradient Echoes (MP2RAGE) acquisition on participants clinically diagnosed with multiple sclerosis (MS), bypassing registration errors. Methods Brain scans Segmentation from 3T and 7T scanners were analyzed with software packages such as FreeSurfer, Classification using Derivative-based Features (C-DEF), nnU-net, and a novel 3T-to-7T transfer learning method, Pseudo-Label Assisted nnU-Net (PLAn). 3T and 7T MRIs acquired within 9 months from 25 study participants with MS (Cohort 1) were used for training and optimizing. Eight MS patients (Cohort 2) scanned only at 7T, but with expert annotated lesion segmentation, was used to further validate the algorithm on a completely unseen dataset. Segmentation results were rated visually by experts in a blinded fashion and quantitatively using Dice Similarity Coefficient (DSC). Results Of the methods explored here, nnU-Net and PLAn produced the best tissue segmentation at 7T for all tissue classes. In both quantitative and qualitative analysis, PLAn significantly outperformed nnU-Net (and other methods) in lesion detection in both cohorts. PLAn's lesion DSC improved by 16% compared to nnU-Net. Discussion Limited availability of labeled data makes transfer learning an attractive option, and pre-training a nnUNet model using readily obtained 3T pseudo-labels was shown to boost lesion detection capabilities at 7T.
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Affiliation(s)
- Corinne Donnay
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD, United States
| | - Henry Dieckhaus
- qMRI Core, NINDS, National Institutes of Health, Bethesda, MD, United States
| | - Charidimos Tsagkas
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD, United States
| | - María Inés Gaitán
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD, United States
| | - Erin S. Beck
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD, United States
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Andrew Mullins
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD, United States
- qMRI Core, NINDS, National Institutes of Health, Bethesda, MD, United States
| | - Daniel S. Reich
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD, United States
| | - Govind Nair
- qMRI Core, NINDS, National Institutes of Health, Bethesda, MD, United States
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Prener M, Opheim G, Simonsen HJ, Engelmann CM, Ziebell M, Carlsen J, Paulson OB. Delineation of Grade II and III Gliomas Investigated by 7T MRI: An Inter-Observer Pilot Study. Diagnostics (Basel) 2023; 13:diagnostics13081365. [PMID: 37189466 DOI: 10.3390/diagnostics13081365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 03/27/2023] [Accepted: 03/31/2023] [Indexed: 05/17/2023] Open
Abstract
PURPOSE Diffuse low-grade gliomas (DLGGs) are low-malignancy brain tumors originating from the glial cells of the brain growing continuously and infiltratively along the neural axons and infiltrating the surrounding brain tissue. DLGGs usually transform into higher malignancy, causing progressive disability and premature death. MRI scans are valuable when assessing soft tissue abnormalities, but, due to the infiltrative properties of DLGGs, delineating the tumor borders is a challenging task. Therefore, the aim of this study was to explore the difference in gross tumor volume (GTV) of DLGGs delineated from 7 Tesla and 3 Tesla MRI scans. METHOD Patients were recruited at the department of neurosurgery and were scanned in both a 7T and a 3T MRI scanner prior to the operation. Two observers delineated the tumors using semi-automatic delineation software. The results from each observer were blinded to the other observer's delineation. RESULTS Comparing GTVs from 7T and 3T, the percentage difference varied up to 40.4% on the T2-weighted images. The percentage difference in GTV varied up to 15.3% on the fluid-attenuated inversion recovery (FLAIR) images. On the T2-weighted images, most cases varied by approximately 15%; on the FLAIR sequence, half of the cases varied by approximately 5% and the other half by approximately 15%. The overall inter-observer agreement was near perfect, with an intraclass correlation of 0.969. The intraclass correlation was better on the FLAIR sequence than on the T2 sequence. CONCLUSION Overall, the GTVs delineated from 7T images were smaller. The increase in field strength improved the inter-observer agreement only on the FLAIR sequence.
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Affiliation(s)
- Martin Prener
- Neurobiology Research Unit, Rigshospitalet Blegdamsvej, 2100 Copenhagen, Denmark
| | - Giske Opheim
- Neurobiology Research Unit, Rigshospitalet Blegdamsvej, 2100 Copenhagen, Denmark
| | - Helle Juhl Simonsen
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet Glostrup, 2600 Copenhagen, Denmark
| | | | - Morten Ziebell
- Department of Neurosurgery, Rigshospitalet Blegdamsvej, 2100 Copenhagen, Denmark
| | - Jonathan Carlsen
- Department of Radiology, Rigshospitalet Blegdamsvej, 2100 Copenhagen, Denmark
| | - Olaf B Paulson
- Neurobiology Research Unit, Rigshospitalet Blegdamsvej, 2100 Copenhagen, Denmark
- Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
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Koemans EA, van Walderveen MAA, Voigt S, Rasing I, van Harten TW, J A van Os H, van der Weerd N, Terwindt GM, van Osch MJP, van Veluw SJ, Freeze WM, Wermer MJH. Subarachnoid CSF hyperintensities at 7 tesla FLAIR MRI: A novel marker in cerebral amyloid angiopathy. Neuroimage Clin 2023; 38:103386. [PMID: 36989852 PMCID: PMC10074985 DOI: 10.1016/j.nicl.2023.103386] [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: 12/27/2022] [Revised: 02/25/2023] [Accepted: 03/24/2023] [Indexed: 03/28/2023]
Abstract
BACKGROUND We observed subarachnoid cerebrospinal fluid (CSF) hyperintensities at non-contrast 7-tesla (T) fluid-attenuated inversion recovery (FLAIR) MRI, frequently topographically associated with cortical superficial siderosis (cSS), in participants with cerebral amyloid angiopathy (CAA). To systemically evaluate these CSF hyperintensities we investigated their frequency and anatomical and temporal relationship with cSS on 7T and 3T MRI in hereditary Dutch-type CAA (D-CAA), sporadic CAA (sCAA), and non-CAA controls. METHODS CAA participants were included from two prospective natural history studies and non-CAA controls from a 7T study in healthy females and females with ischemic stroke. CSF hyperintensities were scored by two independent observers. RESULTS We included 38 sCAA participants (mean age 72y), 50 D-CAA participants (mean age 50y) and 44 non-CAA controls (mean age 53y, 15 with stroke). In total 27/38 (71 %, 95 %CI 56-84) sCAA and 23/50 (46 %, 95 %CI 33-60) D-CAA participants had subarachnoid CSF hyperintensities at baseline 7T. Most (96 %) of those had cSS, in 54 % there was complete topographical overlap with cSS. The remaining 46 % had ≥1 sulcus with CSF hyperintensities without co-localizing cSS. None of the healthy controls and 2/15 (13 %, 95 %CI 2-41, 100 % cSS overlap) of the stroke controls had CSF hyperintensities. In 85 % of the CAA participants CSF hyperintensities could retrospectively be identified at 3T. Of the 35 CAA participants with follow-up 7T after two years, 17/35 (49 %) showed increase and 6/35 (17 %) decrease of regional CSF hyperintensities. In 2/11 (18 %) of participants with follow-up who had baseline CSF hyperintensities without overlapping cSS, new cSS developed at those locations. CONCLUSIONS Subarachnoid CSF hyperintensities at 7T FLAIR MRI occur frequently in CAA and are associated with cSS, although without complete overlap. We hypothesize that the phenomenon could be a sign of subtle plasma protein or blood product leakage into the CSF, resulting in CSF T1-shortening.
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Affiliation(s)
- Emma A Koemans
- Leiden University Medical Center, Department of Neurology, Leiden, The Netherlands.
| | | | - Sabine Voigt
- Leiden University Medical Center, Department of Neurology, Leiden, The Netherlands; Leiden University Medical Center, Department of Radiology, Leiden, The Netherlands
| | - Ingeborg Rasing
- Leiden University Medical Center, Department of Neurology, Leiden, The Netherlands
| | - Thijs W van Harten
- Leiden University Medical Center, Department of Radiology, Leiden, The Netherlands
| | - Hine J A van Os
- Leiden University Medical Center, Department of Neurology, Leiden, The Netherlands; Leiden University Medical Center, Department of Public Health, Leiden, The Netherlands
| | | | - Gisela M Terwindt
- Leiden University Medical Center, Department of Neurology, Leiden, The Netherlands
| | | | - Susanne J van Veluw
- Leiden University Medical Center, Department of Radiology, Leiden, The Netherlands; Massachusetts General Hospital, Harvard Medical School, J. Philip Kistler Stroke Research Center, Boston, MA, USA; Massachusetts General Hospital, MassGeneral Institute for Neurodegenerative Disease, Charlestown, MA, USA
| | - Whitney M Freeze
- Leiden University Medical Center, Department of Radiology, Leiden, The Netherlands
| | - Marieke J H Wermer
- Leiden University Medical Center, Department of Neurology, Leiden, The Netherlands
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Raventhiranathan N, Hussien AR, Mirchia K, Swarnkar A, Mangla R. Striatal dominant lupus encephalitis–Is it vasculitis or an autoimmune process? Literature review & new case report with vessel wall imaging. Radiol Case Rep 2022; 17:1205-1210. [PMID: 35169429 PMCID: PMC8829497 DOI: 10.1016/j.radcr.2022.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 11/17/2022] Open
Affiliation(s)
- Neveada Raventhiranathan
- Department of Radiology, State University of New York Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210
- Corresponding author.
| | | | - Kavya Mirchia
- Department of Radiology, State University of New York Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210
| | - Amar Swarnkar
- Department of Radiology, State University of New York Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210
| | - Rajiv Mangla
- Department of Radiology, State University of New York Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210
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Kakkar P, Kakkar T, Patankar T, Saha S. Current approaches and advances in the imaging of stroke. Dis Model Mech 2021; 14:273651. [PMID: 34874055 PMCID: PMC8669490 DOI: 10.1242/dmm.048785] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
A stroke occurs when the blood flow to the brain is suddenly interrupted, depriving brain cells of oxygen and glucose and leading to further cell death. Neuroimaging techniques, such as computed tomography and magnetic resonance imaging, have greatly improved our ability to visualise brain structures and are routinely used to diagnose the affected vascular region of a stroke patient's brain and to inform decisions about clinical care. Currently, these multimodal imaging techniques are the backbone of the clinical management of stroke patients and have immensely improved our ability to visualise brain structures. Here, we review recent developments in the field of neuroimaging and discuss how different imaging techniques are used in the diagnosis, prognosis and treatment of stroke. Summary: Stroke imaging has undergone seismic shifts in the past decade. Although magnetic resonance imaging (MRI) is superior to computed tomography in providing vital information, further research on MRI is still required to bring its full potential into clinical practice.
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Affiliation(s)
- Pragati Kakkar
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | - Tarun Kakkar
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | | | - Sikha Saha
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
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Platt T, Ladd ME, Paech D. 7 Tesla and Beyond: Advanced Methods and Clinical Applications in Magnetic Resonance Imaging. Invest Radiol 2021; 56:705-725. [PMID: 34510098 PMCID: PMC8505159 DOI: 10.1097/rli.0000000000000820] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/07/2021] [Accepted: 08/07/2021] [Indexed: 12/15/2022]
Abstract
ABSTRACT Ultrahigh magnetic fields offer significantly higher signal-to-noise ratio, and several magnetic resonance applications additionally benefit from a higher contrast-to-noise ratio, with static magnetic field strengths of B0 ≥ 7 T currently being referred to as ultrahigh fields (UHFs). The advantages of UHF can be used to resolve structures more precisely or to visualize physiological/pathophysiological effects that would be difficult or even impossible to detect at lower field strengths. However, with these advantages also come challenges, such as inhomogeneities applying standard radiofrequency excitation techniques, higher energy deposition in the human body, and enhanced B0 field inhomogeneities. The advantages but also the challenges of UHF as well as promising advanced methodological developments and clinical applications that particularly benefit from UHF are discussed in this review article.
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Affiliation(s)
- Tanja Platt
- From the Medical Physics in Radiology, German Cancer Research Center (DKFZ)
| | - Mark E. Ladd
- From the Medical Physics in Radiology, German Cancer Research Center (DKFZ)
- Faculty of Physics and Astronomy
- Faculty of Medicine, University of Heidelberg, Heidelberg
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen
| | - Daniel Paech
- Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg
- Clinic for Neuroradiology, University of Bonn, Bonn, Germany
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Huntoon K, Makary MS, Damante M, Giglio P, Slone W, Elder JB. Intraoperative 3 T MRI is more correlative to residual disease extent than early postoperative MRI. J Neurooncol 2021; 154:345-351. [PMID: 34417709 DOI: 10.1007/s11060-021-03833-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/18/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE Extent of resection of low grade glioma (LGG) is an important prognostic variable, and may influence decisions regarding adjuvant therapy in certain patient populations. Immediate postoperative magnetic resonance image (MRI) is the mainstay for assessing residual tumor. However, previous studies have suggested that early postoperative MRI fluid-attenuated inversion recovery (FLAIR) (within 48 h) may overestimate residual tumor volume in LGG. Intraoperative magnetic resonance imaging (iMRI) without subsequent resection may more accurately assess residual tumor. Consistency in MRI techniques and utilization of higher magnet strengths may further improve both comparisons between MRI studies performed at different time points as well as the specificity of MRI findings to identify residual tumor. To evaluate the utility of 3 T iMRI in the imaging of LGG, we volumetrically analyzed intraoperative, early, and late (~ 3 months after surgery) postoperative MRIs after resection of LGG. METHODS A total of 32 patients with LGG were assessed retrospectively. Residual tumor was defined as hyperintense T2 signal on FLAIR. Volumetric assessment was performed with intraoperative, early, and late postoperative FLAIR via TeraRecon iNtuition. RESULTS Perilesional FLAIR parenchymal abnormality volumes were significantly different comparing intraoperative and early postoperative MRI (2.17 ± 0.45 cm3 vs. 5.47 ± 1.07 cm3, respectively (p = 0.0002)). A significant difference of perilesional FLAIR parenchymal abnormality volumes was also found comparing early and late postoperative MRI (5.47 ± 1.07 cm3 vs. 3.22 ± 0.64 cm3, respectively (p = 0.0001)). There was no significant difference between intraoperative and late postoperative Perilesional FLAIR parenchymal abnormality volumes. CONCLUSIONS Intraoperative 3 T MRI without further resection appears to better reflect the volume of residual tumor in LGG compared with early postoperative 3 T MRI. Early postoperative MRI may overestimate residual tumor. As such, intraoperative MRI performed after completion of tumor resection may be more useful for making decisions regarding adjuvant therapy.
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Affiliation(s)
- Kristin Huntoon
- Department of Neurological Surgery, Ohio State University Wexner Medical Center, Columbus, OH, USA. .,Department of Neurological Surgery, MD Anderson Cancer Center, University of Texas, 1515 Holcombe, Houston, TX, 77030, USA.
| | - Mina S Makary
- Department of Radiology, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Mark Damante
- Department of Neurological Surgery, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Pierre Giglio
- Department of Neurology, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Wayne Slone
- Department of Radiology, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - J Bradley Elder
- Department of Neurological Surgery, Ohio State University Wexner Medical Center, Columbus, OH, USA
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11
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Improved 7 Tesla transmit field homogeneity with reduced electromagnetic power deposition using coupled Tic Tac Toe antennas. Sci Rep 2021; 11:3370. [PMID: 33564013 PMCID: PMC7873125 DOI: 10.1038/s41598-020-79807-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 11/26/2020] [Indexed: 12/28/2022] Open
Abstract
Recently cleared by the FDA, 7 Tesla (7 T) MRI is a rapidly growing technology that can provide higher resolution and enhanced contrast in human MRI images. However, the increased operational frequency (~ 297 MHz) hinders its full potential since it causes inhomogeneities in the images and increases the power deposition in the tissues. This work describes the optimization of an innovative radiofrequency (RF) head coil coupled design, named Tic Tac Toe, currently used in large scale human MRI scanning at 7 T; to date, this device was used in more than 1,300 neuro 7 T MRI scans. Electromagnetic simulations of the coil were performed using the finite-difference time-domain method. Numerical optimizations were used to combine the calculated electromagnetic fields produced by these antennas, based on the superposition principle, resulting in homogeneous magnetic field distributions at low levels of power deposition in the tissues. The simulations were validated in-vivo using the Tic Tac Toe RF head coil system on a 7 T MRI scanner.
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12
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Abbasi-Rad S, O'Brien K, Kelly S, Vegh V, Rodell A, Tesiram Y, Jin J, Barth M, Bollmann S. Improving FLAIR SAR efficiency at 7T by adaptive tailoring of adiabatic pulse power through deep learning B 1 + estimation. Magn Reson Med 2020; 85:2462-2476. [PMID: 33226685 DOI: 10.1002/mrm.28590] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 10/15/2020] [Accepted: 10/19/2020] [Indexed: 01/22/2023]
Abstract
PURPOSE The purpose of this study is to demonstrate a method for specific absorption rate (SAR) reduction for 2D T2 -FLAIR MRI sequences at 7 T by predicting the required adiabatic radiofrequency (RF) pulse power and scaling the RF amplitude in a slice-wise fashion. METHODS We used a time-resampled frequency-offset corrected inversion (TR-FOCI) adiabatic pulse for spin inversion in a T2 -FLAIR sequence to improve B 1 + homogeneity and calculated the pulse power required for adiabaticity slice-by-slice to minimize the SAR. Drawing on the implicit B 1 + inhomogeneity in a standard localizer scan, we acquired 3D AutoAlign localizers and SA2RAGE B 1 + maps in 28 volunteers. Then, we trained a convolutional neural network (CNN) to estimate the B 1 + profile from the localizers and calculated pulse scale factors for each slice. We assessed the predicted B 1 + profiles and the effect of scaled pulse amplitudes on the FLAIR inversion efficiency in oblique transverse, sagittal, and coronal orientations. RESULTS The predicted B 1 + amplitude maps matched the measured ones with a mean difference of 9.5% across all slices and participants. The slice-by-slice scaling of the TR-FOCI inversion pulse was most effective in oblique transverse orientation and resulted in a 1 min and 30 s reduction in SAR induced delay time while delivering identical image quality. CONCLUSION We propose a SAR reduction technique based on the estimation of B 1 + profiles from standard localizer scans using a CNN and show that scaling the inversion pulse power slice-by-slice for FLAIR sequences at 7T reduces SAR and scan time without compromising image quality.
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Affiliation(s)
- Shahrokh Abbasi-Rad
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia
| | - Kieran O'Brien
- Siemens Healthcare Pty Ltd, Brisbane, Queensland, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, Queensland, Australia
| | - Samuel Kelly
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia
| | - Viktor Vegh
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, Queensland, Australia
| | - Anders Rodell
- Siemens Healthcare Pty Ltd, Brisbane, Queensland, Australia
| | - Yasvir Tesiram
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia
| | - Jin Jin
- Siemens Healthcare Pty Ltd, Brisbane, Queensland, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, Queensland, Australia
| | - Markus Barth
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, Queensland, Australia.,School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Queensland, Australia
| | - Steffen Bollmann
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia.,ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, Queensland, Australia.,School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Queensland, Australia
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13
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Gupta T, Gandhi TK, Gupta R, Panigrahi B. Classification of patients with tumor using MR FLAIR images. Pattern Recognit Lett 2020. [DOI: 10.1016/j.patrec.2017.10.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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14
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Automated Detection and Segmentation of Multiple Sclerosis Lesions Using Ultra-High-Field MP2RAGE. Invest Radiol 2020; 54:356-364. [PMID: 30829941 DOI: 10.1097/rli.0000000000000551] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVES The aim of this study was to develop a new automated segmentation method of white matter (WM) and cortical multiple sclerosis (MS) lesions visible on magnetization-prepared 2 inversion-contrast rapid gradient echo (MP2RAGE) images acquired at 7 T MRI. MATERIALS AND METHODS The proposed prototype (MSLAST [Multiple Sclerosis Lesion Analysis at Seven Tesla]) takes as input a single image contrast derived from the 7T MP2RAGE prototype sequence and is based on partial volume estimation and topological constraints. First, MSLAST performs a skull-strip of MP2RAGE images and computes tissue concentration maps for WM, gray matter (GM), and cerebrospinal fluid (CSF) using a partial volume model of tissues within each voxel. Second, MSLAST performs (1) connected-component analysis to GM and CSF concentration maps to classify small isolated components as MS lesions; (2) hole-filling in the WM concentration map to classify areas with low WM concentration surrounded by WM (ie, MS lesions); and (3) outlier rejection to the WM mask to improve the classification of small WM lesions. Third, MSLAST unifies the 3 maps obtained from 1, 2, and 3 processing steps to generate a global lesion mask. RESULTS Quantitative and qualitative assessments were performed using MSLAST in 25 MS patients from 2 research centers. Overall, MSLAST detected a median of 71% of MS lesions, specifically 74% of WM and 58% of cortical lesions, when a minimum lesion size of 6 μL was considered. The median false-positive rate was 40%. When a 15 μL minimal lesions size was applied, which is the approximation of the minimal size recommended for 1.5/3 T images, the median detection rate was 80% for WM and 63% for cortical lesions, respectively, and the median false-positive rate was 33%. We observed high correlation between MSLAST and manual segmentations (Spearman rank correlation coefficient, ρ = 0.91), although MSLAST underestimated the total lesion volume (average difference of 1.1 mL), especially in patients with high lesion loads. MSLAST also showed good scan-rescan repeatability within the same session with an average absolute volume difference and F1 score of 0.38 ± 0.32 mL and 84%, respectively. CONCLUSIONS We propose a new methodology to facilitate the segmentation of WM and cortical MS lesions at 7 T MRI, our approach uses a single MP2RAGE scan and may be of special interest to clinicians and researchers.
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15
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Knowles BR, Friedrich F, Fischer C, Paech D, Ladd ME. Beyond T2 and 3T: New MRI techniques for clinicians. Clin Transl Radiat Oncol 2019; 18:87-97. [PMID: 31341982 PMCID: PMC6630188 DOI: 10.1016/j.ctro.2019.04.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 04/11/2019] [Accepted: 04/11/2019] [Indexed: 12/12/2022] Open
Abstract
Technological advances in Magnetic Resonance Imaging (MRI) in terms of field strength and hybrid MR systems have led to improvements in tumor imaging in terms of anatomy and functionality. This review paper discusses the applications of such advances in the field of radiation oncology with regards to treatment planning, therapy guidance and monitoring tumor response and predicting outcome.
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Affiliation(s)
- Benjamin R. Knowles
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Florian Friedrich
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Carola Fischer
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Daniel Paech
- Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Mark E. Ladd
- Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
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16
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Age- and disease-related cerebral white matter changes in patients with Parkinson's disease. Neurobiol Aging 2019; 80:203-209. [DOI: 10.1016/j.neurobiolaging.2019.05.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/26/2019] [Accepted: 05/06/2019] [Indexed: 11/18/2022]
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17
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Marques JP, Simonis FF, Webb AG. Low-field MRI: An MR physics perspective. J Magn Reson Imaging 2019; 49:1528-1542. [PMID: 30637943 PMCID: PMC6590434 DOI: 10.1002/jmri.26637] [Citation(s) in RCA: 149] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/28/2018] [Accepted: 11/28/2018] [Indexed: 01/21/2023] Open
Abstract
Historically, clinical MRI started with main magnetic field strengths in the ∼0.05-0.35T range. In the past 40 years there have been considerable developments in MRI hardware, with one of the primary ones being the trend to higher magnetic fields. While resulting in large improvements in data quality and diagnostic value, such developments have meant that conventional systems at 1.5 and 3T remain relatively expensive pieces of medical imaging equipment, and are out of the financial reach for much of the world. In this review we describe the current state-of-the-art of low-field systems (defined as 0.25-1T), both with respect to its low cost, low foot-print, and subject accessibility. Furthermore, we discuss how low field could potentially benefit from many of the developments that have occurred in higher-field MRI. In the first section, the signal-to-noise ratio (SNR) dependence on the static magnetic field and its impact on the achievable contrast, resolution, and acquisition times are discussed from a theoretical perspective. In the second section, developments in hardware (eg, magnet, gradient, and RF coils) used both in experimental low-field scanners and also those that are currently in the market are reviewed. In the final section the potential roles of new acquisition readouts, motion tracking, and image reconstruction strategies, currently being developed primarily at higher fields, are presented. Level of Evidence: 5 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019.
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Affiliation(s)
- José P. Marques
- Radboud University, Donders Institute for Brain, Cognition and BehaviourNijmegenThe Netherlands
| | - Frank F.J. Simonis
- Magnetic Detection & Imaging, Technical Medical CentreUniversity of TwenteThe Netherlands
| | - Andrew G. Webb
- C.J.Gorter Center for High Field MRI, Department of RadiologyLeiden University Medical CentreThe Netherlands
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18
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Abstract
PURPOSE OF REVIEW MRI has a crucial position in the diagnostic routine of epilepsy patients. It relevantly contributes to etiological diagnostics and is indispensable in presurgical evaluation. As modern MRI research has been a boon to clinical neuroscience in general, it also holds the promise of enhancing diagnostics of epilepsy patients; i.e. increasing the diagnostic yield while decreasing the number of MRI-negative patients. Its rapid progress, however, has caused uncertainty about which of its latest developments already are of clinical interest and which still are of academic interest. It is the purpose of this review to clarify what, to the authors' mind, good practice of MRI in epilepsy patient care is today and what it might be tomorrow. RECENT FINDINGS Progress of diagnostic MRI in epilepsy patients is driven by development of scanner hardware, scanner sequence and data postprocessing. Ultra high-field MRI and elaborate sequences provide datasets of novel quality which can be fed into postprocessing programs extracting pathognomonic features of structural or functional anatomy. The integration of these features by means of computerized classifiers yield previously unsurpassed diagnostic validity. Enthusiasm about Diffusion Tensor Imaging and functional MRI in the evaluation before epilepsy surgery is quelled. SUMMARY The application of an epilepsy tailored MRI protocol at 3 Tesla followed by meticulous expert evaluation early after the onset of epilepsy is most crucial. It is hoped that future research will result in MRI workups more standardized than today and widely used postprocessing routines analyzing co-registered three-dimensional volumes from different modalities.
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19
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Farhat NS, Theiss R, Santini T, Ibrahim TS, Aizenstein HJ. Neuroimaging of Small Vessel Disease in Late-Life Depression. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1192:95-115. [PMID: 31705491 PMCID: PMC6939470 DOI: 10.1007/978-981-32-9721-0_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cerebral small vessel disease is associated with late-life depression, cognitive impairment, executive dysfunction, distress, and loss of life for older adults. Late-life depression is becoming a substantial public health burden, and a considerable number of older adults presenting to primary care have significant clinical depression. Even though white matter hyperintensities are linked with small vessel disease, white matter hyperintensities are nonspecific to small vessel disease and can co-occur with other brain diseases. Advanced neuroimaging techniques at the ultrahigh field magnetic resonance imaging are enabling improved characterization, identification of cerebral small vessel disease and are elucidating some of the mechanisms that associate small vessel disease with late-life depression.
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Affiliation(s)
- Nadim S Farhat
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Robert Theiss
- School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tales Santini
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tamer S Ibrahim
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Radiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Howard J Aizenstein
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
- Clinical and Translational Science Institute, University of Pittsburgh, Pittsburgh, PA, USA.
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20
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High-resolution FLAIR MRI at 7 Tesla for treatment planning in glioblastoma patients. Radiother Oncol 2018; 130:180-184. [PMID: 30177373 DOI: 10.1016/j.radonc.2018.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 07/10/2018] [Accepted: 08/17/2018] [Indexed: 11/24/2022]
Abstract
Ultra-high field MRI is an emerging technique promising high-resolution images for radiotherapy planning. We compared a 7 Tesla FLAIR sequence with clinical FLAIR imaging at 3 Tesla in glioblastoma patients before radiotherapy. High-resolution 7 Tesla FLAIR imaging may enhance the depiction of organs at risk and possibly modify target volumes.
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21
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Protti A, Jones KL, Bonal DM, Qin L, Politi LS, Kravets S, Nguyen QD, Van den Abbeele AD. Development and validation of a new MRI simulation technique that can reliably estimate optimal in vivo scanning parameters in a glioblastoma murine model. PLoS One 2018; 13:e0200611. [PMID: 30036367 PMCID: PMC6056046 DOI: 10.1371/journal.pone.0200611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 06/29/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Magnetic Resonance Imaging (MRI) relies on optimal scanning parameters to achieve maximal signal-to-noise ratio (SNR) and high contrast-to-noise ratio (CNR) between tissues resulting in high quality images. The optimization of such parameters is often laborious, time consuming, and user-dependent, making harmonization of imaging parameters a difficult task. In this report, we aim to develop and validate a computer simulation technique that can reliably provide "optimal in vivo scanning parameters" ready to be used for in vivo evaluation of disease models. METHODS A glioblastoma murine model was investigated using several MRI imaging methods. Such MRI methods underwent a simulated and an in vivo scanning parameter optimization in pre- and post-contrast conditions that involved the investigation of tumor, brain parenchyma and cerebrospinal fluid (CSF) CNR values in addition to the time relaxation values of the related tissues. The CNR tissues information were analyzed and the derived scanning parameters compared in order to validate the simulated methodology as a reliable technique for "optimal in vivo scanning parameters" estimation. RESULTS The CNRs and the related scanning parameters were better correlated when spin-echo-based sequences were used rather than the gradient-echo-based sequences due to augmented inhomogeneity artifacts affecting the latter methods. "Optimal in vivo scanning parameters" were generated successfully by the simulations after initial scanning parameter adjustments that conformed to some of the parameters derived from the in vivo experiment. CONCLUSION Scanning parameter optimization using the computer simulation was shown to be a valid surrogate to the in vivo approach in a glioblastoma murine model yielding in a better delineation and differentiation of the tumor from the contralateral hemisphere. In addition to drastically reducing the time invested in choosing optimal scanning parameters when compared to an in vivo approach, this simulation program could also be used to harmonize MRI acquisition parameters across scanners from different vendors.
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Affiliation(s)
- Andrea Protti
- Department of Imaging, Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Kristen L. Jones
- Department of Imaging, Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Dennis M. Bonal
- Department of Imaging, Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lei Qin
- Department of Imaging, Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Letterio S. Politi
- Neuroimaging Research, Radiology Department, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Radiology Department, University of Massachusetts Medical School, Worcester, MA, United States of America
- University of Massachusetts Memorial Medical Center, Worcester, MA, United States of America
| | - Sasha Kravets
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Quang-Dé Nguyen
- Department of Imaging, Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Annick D. Van den Abbeele
- Department of Imaging, Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
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22
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Keuken MC, Isaacs BR, Trampel R, van der Zwaag W, Forstmann BU. Visualizing the Human Subcortex Using Ultra-high Field Magnetic Resonance Imaging. Brain Topogr 2018; 31:513-545. [PMID: 29497874 PMCID: PMC5999196 DOI: 10.1007/s10548-018-0638-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 01/28/2018] [Indexed: 12/15/2022]
Abstract
With the recent increased availability of ultra-high field (UHF) magnetic resonance imaging (MRI), substantial progress has been made in visualizing the human brain, which can now be done in extraordinary detail. This review provides an extensive overview of the use of UHF MRI in visualizing the human subcortex for both healthy and patient populations. The high inter-subject variability in size and location of subcortical structures limits the usability of atlases in the midbrain. Fortunately, the combined results of this review indicate that a large number of subcortical areas can be visualized in individual space using UHF MRI. Current limitations and potential solutions of UHF MRI for visualizing the subcortex are also discussed.
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Affiliation(s)
- M C Keuken
- Integrative Model-Based Cognitive Neuroscience Research Unit, University of Amsterdam, Postbus 15926, 1001NK, Amsterdam, The Netherlands.
- Cognitive Psychology Unit, Institute of Psychology and Leiden Institute for Brain and Cognition, Leiden University, Leiden, The Netherlands.
| | - B R Isaacs
- Integrative Model-Based Cognitive Neuroscience Research Unit, University of Amsterdam, Postbus 15926, 1001NK, Amsterdam, The Netherlands
- Maastricht University Medical Center, Maastricht, The Netherlands
| | - R Trampel
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | | | - B U Forstmann
- Integrative Model-Based Cognitive Neuroscience Research Unit, University of Amsterdam, Postbus 15926, 1001NK, Amsterdam, The Netherlands
- Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
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23
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Hosseini Z, Matusinec J, Rudko DA, Liu J, Kwan BYM, Salehi F, Sharma M, Kremenchutzky M, Menon RS, Drangova M. Morphology-Specific Discrimination between MS White Matter Lesions and Benign White Matter Hyperintensities Using Ultra-High-Field MRI. AJNR Am J Neuroradiol 2018; 39:1473-1479. [PMID: 29930096 DOI: 10.3174/ajnr.a5705] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 05/05/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Recently published North American Imaging in Multiple Sclerosis guidelines call for derivation of a specific radiologic definition of MS WM lesions and mimics. The purpose of this study was to use SWI and magnetization-prepared FLAIR images for sensitive differentiation of MS from benign WM lesions using the morphologic characteristics of WM lesions. MATERIALS AND METHODS Seventeen patients with relapsing-remitting MS and 18 healthy control subjects were enrolled retrospectively. For each subject, FLAIR and multiecho gradient-echo images were acquired using 7T MR imaging. Optimized postprocessing was used to generate single-slice SWI of cerebral veins. SWI/FLAIR images were registered, and 3 trained readers performed lesion assessment. Morphology, location of lesions, and the time required for assessment were recorded. Analyses were performed on 3 different pools: 1) lesions of >3 mm, 2) nonconfluent lesions of >3 mm, and 3) nonconfluent lesions of >3 mm with no or a single central vein. RESULTS The SWI/FLAIR acquisition and processing protocol enabled effective assessment of central veins and hypointense rims in WM lesions. Assessment of nonconfluent lesions with ≥1 central vein enabled the most specific and sensitive differentiation of patients with MS from controls. A threshold of 67% perivenous WM lesions separated patients with MS from controls with a sensitivity of 94% and specificity of 100%. Lesion assessment took an average of 12 minutes 10 seconds and 4 minutes 33 seconds for patients with MS and control subjects, respectively. CONCLUSIONS Nonconfluent lesions of >3 mm with ≥1 central vein were the most sensitive and specific differentiators between patients with MS and control subjects.
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Affiliation(s)
- Z Hosseini
- From the Biomedical Engineering Graduate Program (Z.H., R.S.M., M.D.).,Imaging Research Laboratories (Z.H., J.L., R.S.M., M.D.), Robarts Research Institute
| | | | - D A Rudko
- Department of Neurology and Neurosurgery (D.A.R.), McConnell Brain Imaging Centre, Montreal Neurological Institute.,Department of Biomedical Engineering (D.A.R.), McGill University, Montreal, Quebec, Canada
| | - J Liu
- Imaging Research Laboratories (Z.H., J.L., R.S.M., M.D.), Robarts Research Institute
| | | | - F Salehi
- Medical Imaging (B.Y.M.K., F.S., M.S.)
| | - M Sharma
- Medical Imaging (B.Y.M.K., F.S., M.S.).,Department of Clinical Neurological Sciences (M.S., M.K.), Western University and London Health Sciences Centre, London, Ontario, Canada
| | - M Kremenchutzky
- Department of Clinical Neurological Sciences (M.S., M.K.), Western University and London Health Sciences Centre, London, Ontario, Canada
| | - R S Menon
- From the Biomedical Engineering Graduate Program (Z.H., R.S.M., M.D.).,Imaging Research Laboratories (Z.H., J.L., R.S.M., M.D.), Robarts Research Institute.,Medical Biophysics (R.S.M., M.D.), Schulich School of Medicine and Dentistry; Western University, London, Ontario, Canada
| | - M Drangova
- From the Biomedical Engineering Graduate Program (Z.H., R.S.M., M.D.) .,Imaging Research Laboratories (Z.H., J.L., R.S.M., M.D.), Robarts Research Institute.,Medical Biophysics (R.S.M., M.D.), Schulich School of Medicine and Dentistry; Western University, London, Ontario, Canada
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van Egmond SL, Stegeman I, Pameijer FA, Bluemink JJ, Terhaard CH, Janssen LM. Systematic review of the diagnostic value of magnetic resonance imaging for early glottic carcinoma. Laryngoscope Investig Otolaryngol 2018; 3:49-55. [PMID: 29492468 PMCID: PMC5824105 DOI: 10.1002/lio2.138] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 01/03/2018] [Indexed: 11/25/2022] Open
Abstract
Objective In early glottic cancer, accurate assessment of tumor extension, including depth infiltration, is of great importance for both staging, therapeutic approach and systematic comparison of data. Our goal was to assess the diagnostic value of MRI in pre‐therapeutic staging of primary early stage (T1 and T2) glottic carcinoma. Study design Systematic review of literature. Methods We conducted a systematic search in Pubmed, Embase, and Scopus up to September 23, 2016. Included studies were selected and critically appraised for relevance and validity. Results Seven out of 938 unique articles were selected, including 64 cases. MRI over‐staged 6% and under‐staged 13% of cT1 and cT2 tumors. However, available data is heterogeneous, very limited and mainly based on subanalysis of a small amount of patients. Reported MRI protocols appear to be suboptimal for small laryngeal lesions. Diagnostic value of MRI for subtle depth infiltration or laryngeal anatomical subsites (eg, laryngeal ventricle, vocal cord, etc.) could not be assessed. Conclusions More studies are needed to assess the diagnostic value of MRI for small glottic tumors.
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Affiliation(s)
- Sylvia L van Egmond
- Department of Otorhinolaryngology and Head & Neck Surgery UMC Cancer Center University Medical Center Utrecht Utrecht The Netherlands
| | - Inge Stegeman
- Department of Otorhinolaryngology and Head & Neck Surgery UMC Cancer Center University Medical Center Utrecht Utrecht The Netherlands.,Rudolf Magnus Institute of Neuroscience UMC Cancer Center University Medical Center Utrecht Utrecht The Netherlands
| | - Frank A Pameijer
- Department of Radiology UMC Cancer Center University Medical Center Utrecht Utrecht The Netherlands
| | - Johanna J Bluemink
- Department of Radiotherapy UMC Cancer Center University Medical Center Utrecht Utrecht The Netherlands
| | - Chris H Terhaard
- Department of Radiotherapy UMC Cancer Center University Medical Center Utrecht Utrecht The Netherlands
| | - Luuk M Janssen
- Department of Head and Neck Surgical Oncology UMC Cancer Center University Medical Center Utrecht Utrecht The Netherlands
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25
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How to choose the right MR sequence for your research question at 7 T and above? Neuroimage 2018; 168:119-140. [DOI: 10.1016/j.neuroimage.2017.04.044] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 12/29/2022] Open
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26
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Schreiner SJ, Kirchner T, Narkhede A, Wyss M, Van Bergen JMG, Steininger SC, Gietl A, Leh SE, Treyer V, Buck A, Pruessmann KP, Nitsch RM, Hock C, Henning A, Brickman AM, Unschuld PG. Brain amyloid burden and cerebrovascular disease are synergistically associated with neurometabolism in cognitively unimpaired older adults. Neurobiol Aging 2017; 63:152-161. [PMID: 29310864 DOI: 10.1016/j.neurobiolaging.2017.12.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 11/16/2017] [Accepted: 12/04/2017] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease (AD) is the most common cause of cognitive dysfunction in older adults. The pathological hallmarks of AD such as beta amyloid (Aβ) aggregation and neurometabolic change, as indicated by altered myo-inositol (mI) and N-acetylaspartate (NAA) levels, typically precede the onset of cognitive dysfunction by years. Furthermore, cerebrovascular disease occurs early in AD, but the interplay between vascular and neurometabolic brain change is largely unknown. Thirty cognitively normal older adults (age = 70 ± 5.6 years, Mini-Mental State Examination = 29.2 ± 1) received 11-C-Pittsburgh Compound B positron emission tomography for estimating Aβ-plaque density, 7 Tesla fluid-attenuated inversion recovery magnetic resonance imaging for quantifying white matter hyperintensity volume as a marker of small vessel cerebrovascular disease and high-resolution magnetic resonance spectroscopic imaging at 7 Tesla, based on free induction decay acquisition localized by outer volume suppression to investigate tissue-specific neurometabolism in the posterior cingulate and precuneus. Aβ (β = 0.45, p = 0.018) and white matter hyperintensities (β = 0.40, p = 0.046) were independently and interactively (β = -0.49, p = 0.026) associated with a higher ratio of mI over NAA (mI/NAA) in the posterior cingulate and precuneus gray matter but not in the white matter. Our data suggest that cerebrovascular disease and Aβ burden are synergistically associated with AD-related gray matter neurometabolism in older adults.
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Affiliation(s)
- Simon J Schreiner
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Thomas Kirchner
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Atul Narkhede
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Department of Neurology, College of Physicians and Surgeons, Columbia University, NY
| | - Michael Wyss
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Jiri M G Van Bergen
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Stephanie C Steininger
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Anton Gietl
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Sandra E Leh
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Valerie Treyer
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland; Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Alfred Buck
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Klaas P Pruessmann
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Roger M Nitsch
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Christoph Hock
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Anke Henning
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland; Max Planck Institute for Biological Cybernetics, Tubingen, Germany
| | - Adam M Brickman
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Department of Neurology, College of Physicians and Surgeons, Columbia University, NY.
| | - Paul G Unschuld
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
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27
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Vargas MI, Martelli P, Xin L, Ipek O, Grouiller F, Pittau F, Trampel R, Gruetter R, Vulliemoz S, Lazeyras F. Clinical Neuroimaging Using 7 T MRI: Challenges and Prospects. J Neuroimaging 2017; 28:5-13. [PMID: 29205628 DOI: 10.1111/jon.12481] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/02/2017] [Indexed: 01/19/2023] Open
Abstract
The aim of this article is to illustrate the principal challenges, from the medical and technical point of view, associated with the use of ultrahigh field (UHF) scanners in the clinical setting and to present available solutions to circumvent these limitations. We would like to show the differences between UHF scanners and those used routinely in clinical practice, the principal advantages, and disadvantages, the different UHFs that are ready be applied to routine clinical practice such as susceptibility-weighted imaging, fluid-attenuated inversion recovery, 3-dimensional time of flight, magnetization-prepared rapid acquisition gradient echo, magnetization-prepared 2 rapid acquisition gradient echo, and diffusion-weighted imaging, the technical principles of these sequences, and the particularities of advanced techniques such as diffusion tensor imaging, spectroscopy, and functional imaging at 7TMR. Finally, the main clinical applications in the field of the neuroradiology are discussed and the side effects are reported.
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Affiliation(s)
- Maria Isabel Vargas
- Division of Neuroradiology of Geneva University Hospitals and Geneva University, Geneva, Switzerland
| | - Pascal Martelli
- Animal Imaging and Technology Core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Lijing Xin
- Animal Imaging and Technology Core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ozlem Ipek
- Animal Imaging and Technology Core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Frederic Grouiller
- CIBM, Department of Radiology and Medical Informatics, Geneva Hospitals and University of Geneva, Geneva, Switzerland
| | - Francesca Pittau
- Division of Neurology, Epileptology Unit, Geneva University Hospitals, Geneva, Switzerland
| | - Robert Trampel
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Rolf Gruetter
- Animal Imaging and Technology Core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Serge Vulliemoz
- Division of Neurology, Epileptology Unit, Geneva University Hospitals, Geneva, Switzerland
| | - Francois Lazeyras
- CIBM, Department of Radiology and Medical Informatics, Geneva Hospitals and University of Geneva, Geneva, Switzerland.,Division of Radiology of Geneva University Hospitals and CIBM, Geneva, Switzerland
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28
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Chou IJ, Lim SY, Tanasescu R, Al-Radaideh A, Mougin OE, Tench CR, Whitehouse WP, Gowland PA, Constantinescu CS. Seven-Tesla Magnetization Transfer Imaging to Detect Multiple Sclerosis White Matter Lesions. J Neuroimaging 2017; 28:183-190. [DOI: 10.1111/jon.12474] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 08/17/2017] [Accepted: 08/18/2017] [Indexed: 12/26/2022] Open
Affiliation(s)
- I-Jun Chou
- Division of Clinical Neuroscience; University of Nottingham; Nottingham UK
- Division of Academic Child Health; School of Medicine; University of Nottingham; Nottingham UK
- Division of Paediatric Neurology; Chang Gung Memorial Hospital; Taoyuan Taiwan
| | - Su-Yin Lim
- Division of Clinical Neuroscience; University of Nottingham; Nottingham UK
| | - Radu Tanasescu
- Division of Clinical Neuroscience; University of Nottingham; Nottingham UK
- Department of Neurology; Neurosurgery and Psychiatry; Carol Davila University of Medicine and Pharmacy; Colentina Hospital; Bucharest Romania
| | - Ali Al-Radaideh
- Sir Peter Mansfield Magnetic Resonance Centre; School of Physics and Astronomy; University of Nottingham; England UK
- Department of Medical Imaging; Faculty of Allied Health Sciences; Hashemite University; Zarqa Jordan
| | - Olivier E. Mougin
- Sir Peter Mansfield Magnetic Resonance Centre; School of Physics and Astronomy; University of Nottingham; England UK
| | | | - William P. Whitehouse
- Division of Academic Child Health; School of Medicine; University of Nottingham; Nottingham UK
| | - Penny A. Gowland
- Sir Peter Mansfield Magnetic Resonance Centre; School of Physics and Astronomy; University of Nottingham; England UK
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29
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Datta R, Sethi V, Ly S, Waldman AT, Narula S, Dewey BE, Sati P, Reich D, Banwell B. 7T MRI Visualization of Cortical Lesions in Adolescents and Young Adults with Pediatric-Onset Multiple Sclerosis. J Neuroimaging 2017; 27:447-452. [PMID: 28796432 DOI: 10.1111/jon.12465] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/20/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Cortical pathology in multiple sclerosis (MS) has been associated with prolonged and progressive disease. 7T magnetic resonance imaging (MRI) provides enhanced visualization of cortical lesions (CLs). Hence, we conducted a pilot study to explore whether CLs occur early in MS, as evidenced by pediatric-onset patients. METHODS A total of 8 pediatric-onset MS patients were imaged using 7T MRI. CLs were annotated on T1-weighted magnetization-prepared rapid acquisition of gradient echoes images as leukocortical (LC), intracortical, or subpial. Total CLs, age at onset, age at scan, disease duration, total relapses, and Expanded Disability Status Scale (EDSS) score were recorded. RESULTS A median of 120 (range: 48-144) CLs was identified in 8 MS patients (3 female, all with relapsing remitting MS, mean age at scan 21 years ± 3.5 SD, mean age of disease onset 15 years ± 2.3 SD, mean disease duration 5.3 years ± 3.4 SD, median EDSS 2.0). Nearly all the lesions identified were LC. CONCLUSIONS Many CLs are detectable using 7T MRI in patients with pediatric-onset MS despite relatively brief disease duration, absence of progressive disease, and very limited physical disability-supporting early cortical involvement in MS.
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Affiliation(s)
- Ritobrato Datta
- Division of Child Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, Department of Neurology, University of Pennsylvania, Philadelphia, PA.,Translational Neurology Section, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Varun Sethi
- Translational Neurology Section, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Sophia Ly
- Department of Biology, University of Pennsylvania, Philadelphia, PA
| | - Amy T Waldman
- Division of Child Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, Department of Neurology, University of Pennsylvania, Philadelphia, PA.,Translational Neurology Section, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Sona Narula
- Division of Child Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, Department of Neurology, University of Pennsylvania, Philadelphia, PA.,Translational Neurology Section, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Blake E Dewey
- Translational Neurology Section, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Pascal Sati
- Translational Neurology Section, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Daniel Reich
- Translational Neurology Section, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Brenda Banwell
- Division of Child Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, Department of Neurology, University of Pennsylvania, Philadelphia, PA.,Translational Neurology Section, Division of Neuroimmunology and Neurovirology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
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30
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Gupta T, Gandhi TK, Panigrahi B. Multi-sequential MR brain image classification for tumor detection. JOURNAL OF INTELLIGENT & FUZZY SYSTEMS 2017. [DOI: 10.3233/jifs-169293] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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31
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Oh BH, Moon HC, Baek HM, Lee YJ, Kim SW, Jeon YJ, Lee GS, Kim HR, Choi JH, Min KS, Lee MS, Kim YG, Kim DH, Kim WS, Park YS. Comparison of 7T and 3T MRI in patients with moyamoya disease. Magn Reson Imaging 2016; 37:134-138. [PMID: 27899331 DOI: 10.1016/j.mri.2016.11.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 11/25/2016] [Indexed: 11/26/2022]
Abstract
Magnetic resonance imaging and magnetic resonance angiography (MRI/MRA) are widely used for evaluating the moyamoya disease (MMD). This study compared the diagnostic accuracy of 7Tesla (T) and 3T MRI/MRA in MMD. In this case control study, 12 patients [median age: 34years; range (10-66years)] with MMD and 12 healthy controls [median age: 25years; range (22-59years)] underwent both 7T and 3T MRI/MRA. To evaluate the accuracy of MRI/MRA in MMD, five criteria were compared between imaging systems of 7T and 3T: Suzuki grading system, internal carotid artery (ICA) diameter, ivy sign, flow void of the basal ganglia on T2-weighted images, and high signal intensity areas of the basal ganglia on time-of-flight (TOF) source images. No difference was observed between 7T and 3T MRI/MRA in Suzuki stage, ICA diameter, and ivy sign score; while, 7T MRI/MRA showed a higher detection rate in the flow void on T2-weighted images and TOF source images (p<0.001). Receiver operating characteristic curves of both T2 and TOF criteria showed that 7T MRI/MRA had higher sensitivity and specificity than 3T MRI/MRA. Our findings indicate that 7T MRI/MRA is superior to 3T MRI/MRA for the diagnosis of MMD in point of detecting the flow void in basal ganglia by T2-weighted and TOF images.
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Affiliation(s)
- Byeong Ho Oh
- Department of Neurosurgery, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Hyeong Cheol Moon
- Department of Medical Neuroscience, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Hyeon Man Baek
- Bioimaging Research Team, Korea Basic Science Institute, Cheongju, Republic of Korea
| | - Youn Joo Lee
- Department or Radiology, The Catholic University of Korea, Daejeon St. Mary's Hospital, Republic of Korea
| | - Sang Woo Kim
- Bioimaging Research Team, Korea Basic Science Institute, Cheongju, Republic of Korea
| | - Young Jai Jeon
- Bioimaging Research Team, Korea Basic Science Institute, Cheongju, Republic of Korea
| | - Gun Seok Lee
- Department of Neurosurgery, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Hong Rae Kim
- Department of Neurosurgery, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Jai Ho Choi
- Department of Neurosurgery, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Kyung Soo Min
- Department of Neurosurgery, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Mou Seop Lee
- Department of Neurosurgery, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Young Gyu Kim
- Department of Neurosurgery, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Dong Ho Kim
- Department of Neurosurgery, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Won Seop Kim
- Department of Pediatrics, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea
| | - Young Seok Park
- Department of Neurosurgery, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea; Department of Medical Neuroscience, Chungbuk National University Hospital, Chungbuk National University, College of Medicine, Cheongju, Republic of Korea.
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32
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van der Zwaag W, Schäfer A, Marques JP, Turner R, Trampel R. Recent applications of UHF-MRI in the study of human brain function and structure: a review. NMR IN BIOMEDICINE 2016; 29:1274-1288. [PMID: 25762497 DOI: 10.1002/nbm.3275] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/19/2014] [Accepted: 01/22/2015] [Indexed: 06/04/2023]
Abstract
The increased availability of ultra-high-field (UHF) MRI has led to its application in a wide range of neuroimaging studies, which are showing promise in transforming fundamental approaches to human neuroscience. This review presents recent work on structural and functional brain imaging, at 7 T and higher field strengths. After a short outline of the effects of high field strength on MR images, the rapidly expanding literature on UHF applications of blood-oxygenation-level-dependent-based functional MRI is reviewed. Structural imaging is then discussed, divided into sections on imaging weighted by relaxation time, including quantitative relaxation time mapping, phase imaging and quantitative susceptibility mapping, angiography, diffusion-weighted imaging, and finally magnetization-transfer imaging. The final section discusses studies using the high spatial resolution available at UHF to identify explicit links between structure and function. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Wietske van der Zwaag
- Centre d'Imagerie Biomédicale, Ecole Polytechnique Fédérale de Lausanne, Switzerland
| | - Andreas Schäfer
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - José P Marques
- Centre d'Imagerie Biomédicale, Ecole Polytechnique Fédérale de Lausanne, Switzerland
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Robert Turner
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Spinoza Centre, University of Amsterdam, The Netherlands
- SPMMRC, School of Physics and Astronomy, University of Nottingham, UK
| | - Robert Trampel
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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Colon AJ, van Osch MJP, Buijs M, Grond JVD, Boon P, van Buchem MA, Hofman PAM. Detection superiority of 7 T MRI protocol in patients with epilepsy and suspected focal cortical dysplasia. Acta Neurol Belg 2016; 116:259-69. [PMID: 27389578 PMCID: PMC4989014 DOI: 10.1007/s13760-016-0662-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 06/14/2016] [Indexed: 12/12/2022]
Abstract
In 11 adult patients with suspicion of Focal cortical dysplasia (FCD) on 1.5 T (n = 1) or 3 T (n = 10) magnetic resonance imaging (MRI), 7 T MRI was performed. Visibility, extent, morphological features and delineation were independently rated and subsequently discussed by three observers. Additionally, head-to-head comparisons with corresponding 3 T images were made in the eight patients with a previous 3 T MRI and sustained suspicion of FCD. Comparison with histopathology was done in the five patients that underwent surgery. All lesions, seen at 1.5 and 3 T, were also recognized on 7 T. At 7 T FLAIR highlighted the FCD-like lesions best, whereas T2 and T2* were deemed better suited to review structure and extent of the lesion. Image quality with the used 7 T MRI setup was higher than the quality with the used 3 T MRI setup. In 2 out of 11 patients diagnosis changed, in one after re-evaluation of the images, and in the other based on histopathology. With the used 7 T MRI setup, FCD-like lesions can be detected with more confidence and detail as compared to lower field strength. However, concordance between radiologic diagnosis and final diagnosis seems to be lower than expected.
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Affiliation(s)
- A J Colon
- Academic Center for Epileptology Kempenhaeghe, Maastricht Universitair Medisch Centrum + (MUMC+), Sterkselseweg 65, 5590 VE, Heeze, The Netherlands.
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands.
- Department of Neurology, University Hospital Gent, Ghent, Belgium.
| | - M J P van Osch
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - M Buijs
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - J V D Grond
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - P Boon
- Academic Center for Epileptology Kempenhaeghe, Maastricht Universitair Medisch Centrum + (MUMC+), Sterkselseweg 65, 5590 VE, Heeze, The Netherlands
- Department of Neurology, University Hospital Gent, Ghent, Belgium
| | - M A van Buchem
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - P A M Hofman
- Academic Center for Epileptology Kempenhaeghe, Maastricht Universitair Medisch Centrum + (MUMC+), Sterkselseweg 65, 5590 VE, Heeze, The Netherlands
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3D T 2-weighted imaging at 7T using dynamic kT-points on single-transmit MRI systems. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2016; 29:347-58. [DOI: 10.1007/s10334-016-0545-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 03/01/2016] [Accepted: 03/03/2016] [Indexed: 10/22/2022]
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35
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Barrett TF, Sarkiss CA, Dyvorne HA, Lee J, Balchandani P, Shrivastava RK. Application of Ultrahigh Field Magnetic Resonance Imaging in the Treatment of Brain Tumors: A Meta-Analysis. World Neurosurg 2015; 86:450-65. [PMID: 26409071 DOI: 10.1016/j.wneu.2015.09.048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 09/01/2015] [Accepted: 09/02/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Magnetic resonance imaging (MRI) is the imaging modality of choice for the clinical management of brain tumors, and the majority of scanners operate with static magnetic field strengths of 1.5 or 3.0 Tesla (T). During the past decade, ultrahigh field (UHF) MRI has been investigated for its clinical applicability. This meta-analysis evaluates studies pertaining to the application of UHF MRI to patients with brain tumors. METHODS The authors performed a systematic review of the literature. Articles relating to application of UHF MRI to brain anatomy and brain tumors with living subjects were included. Studies were grouped into 1 of 3 categories based on area of focus: "Anatomical Structures Involved with Brain Tumors," "Tumor characterization," and "Treatment Monitoring." Comparison studies with extractable outcomes measure data were analyzed for performance of UHF MRI versus clinical field strengths (1.5 T and 3 T). RESULTS Twenty-four studies (361 subjects) met inclusion criteria. The field of study was heterogeneous and rigorous statistical analysis was not possible. Overall, 279 patients with brain tumors scanned at UHF MRI have been reported. Of these, glioma and glioblastoma multiforme are the most commonly studied lesions (38.9% and 24.4%, respectively). In comparison studies between UHF MRI and clinical field strengths, 24 of 51 patients had outcome measures that were better with UHF MRI, 17 of 24 were equivalent at both field strengths, and 9 were worse at UHF MRI. The most common causes of a worse performance were susceptibility artifacts and magnetic field inhomogeneities (3 of 9). Imaging of the pituitary gland, pineal gland veins, cranial nerves, and tumor microvasculature were all shown to be feasible. CONCLUSIONS UHF MRI shows promise to improve detection and characterization of brain tumors, preoperative planning for neurosurgical resection, and longitudinal monitoring of the effects of radiation and antibody-based therapies. Technical innovations are needed to overcome field inhomogeneity and susceptibility artifacts in certain regions of the skull. Finally, larger studies comparing 1.5 T, 3.0 T, and 7.0 T or greater will determine whether UHF MRI gains acceptance as a clinical standard.
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Affiliation(s)
- Thomas F Barrett
- Department of Neurosurgery, The Mount Sinai Hospital, New York, New York, USA
| | | | - Hadrien A Dyvorne
- The Translational and Molecular Imaging Institute, Mount Sinai Health System, New York, New York, USA
| | - James Lee
- Department of Neurosurgery, The Mount Sinai Hospital, New York, New York, USA
| | - Priti Balchandani
- The Translational and Molecular Imaging Institute, Mount Sinai Health System, New York, New York, USA
| | - Raj K Shrivastava
- Department of Neurosurgery, The Mount Sinai Hospital, New York, New York, USA.
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Age differences in periventricular and deep white matter lesions. Neurobiol Aging 2015; 36:1653-1658. [PMID: 25659858 DOI: 10.1016/j.neurobiolaging.2015.01.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 12/04/2014] [Accepted: 01/03/2015] [Indexed: 11/23/2022]
Abstract
Deep white matter hyperintensity (DWMH) and periventricular (PV) white matter lesion volumes are associated with age and subsequent stroke. We studied age differences in these volumes accounting for collinearity and risk factors. Subjects were 563 healthy family members of early-onset coronary artery disease patients. Using 3T magnetic resonance imaging, lesions were classified as DWMH or PV. Age association with lesion classification was analyzed using random effects Tobit regression, adjusting for intracranial volume (ICV) and risk factors. Subjects were 60% women, 36% African-American, mean age 51 ± 11 years. In multivariable analysis adjusted for PV and ICV, DWMH was associated with age (p < 0.001) and female sex (p = 0.003). PV, adjusted for DWMH and ICV, was age associated (p < 0.001). For each age decade, DWMH showed 0.07 log units/decade greater volume (95% CI = 0.04-0.11); PV was 0.18 log units/decade greater (95% CI = 0.14-0.23); slope differences (p < 0.001). In people with a family history of coronary artery disease, PV and DWMH are independently and differentially associated with age controlling for traditional risk factors.
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van Veluw SJ, Fracasso A, Visser F, Spliet WGM, Luijten PR, Biessels GJ, Zwanenburg JJM. FLAIR images at 7 Tesla MRI highlight the ependyma and the outer layers of the cerebral cortex. Neuroimage 2014; 104:100-9. [PMID: 25315783 DOI: 10.1016/j.neuroimage.2014.10.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 10/01/2014] [Accepted: 10/04/2014] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES Fluid-attenuated inversion recovery (FLAIR) imaging is an important clinical 'work horse' for brain MRI and has proven to facilitate imaging of both intracortical lesions as well as cortical layers at 7T MRI. A prominent observation on 7T FLAIR images is a hyperintense rim at the cortical surface and around the ventricles. We aimed to clarify the anatomical correlates and underlying contrast mechanisms of this hyperintense rim. MATERIALS AND METHODS Two experiments with post-mortem human brain tissue were performed. FLAIR and T2-weighted images were obtained at typical in vivo (0.8mm isotropic) and high resolution (0.25mm isotropic). At one location the cortical surface was partly removed, and scanned again. Imaging was followed by histological and immunohistochemical analysis. Additionally, several simulations were performed to evaluate the potential contribution from an artifact due to water diffusion. RESULTS The hyperintense rim corresponded to the outer - glia rich - layer of the cortex and disappeared upon removal of that layer. At the ventricles, the rim corresponded to the ependymal layer, and was not present at white matter/fluid borders at an artificial cut. The simulations supported the hypothesis that the hyperintense rim reflects the tissue properties in the outer cortical layers (or ependymal layer for the ventricles), and is not merely an artifact, although not all observations were explained by the simulated model of the contrast mechanism. CONCLUSIONS 7T FLAIR seems to amplify the signal from layers I-III of the cortex and the ependyma around the ventricles. Although diffusion of water from layer I into CSF does contribute to this effect, a long T2 relaxation time constant in layer I, and probably also layer II-III, is most likely the major contributor, since the rim disappears upon removal of that layer. This knowledge can help the interpretation of imaging results in cortical development and in patients with cortical pathology.
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Affiliation(s)
- Susanne J van Veluw
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands.
| | - Alessio Fracasso
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, the Netherlands
| | - Fredy Visser
- Department of Radiology, University Medical Center Utrecht, Utrecht, the Netherlands; Philips Healthcare, Best, the Netherlands
| | - Wim G M Spliet
- Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Peter R Luijten
- Department of Radiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Geert Jan Biessels
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Jaco J M Zwanenburg
- Department of Radiology, University Medical Center Utrecht, Utrecht, the Netherlands
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Schreiner SJ, Liu X, Gietl AF, Wyss M, Steininger SC, Gruber E, Treyer V, Meier IB, Kälin AM, Leh SE, Buck A, Nitsch RM, Pruessmann KP, Hock C, Unschuld PG. Regional Fluid-Attenuated Inversion Recovery (FLAIR) at 7 Tesla correlates with amyloid beta in hippocampus and brainstem of cognitively normal elderly subjects. Front Aging Neurosci 2014; 6:240. [PMID: 25249977 PMCID: PMC4159032 DOI: 10.3389/fnagi.2014.00240] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 08/22/2014] [Indexed: 11/13/2022] Open
Abstract
Background: Accumulation of amyloid beta (Aβ) may occur during healthy aging and is a risk factor for Alzheimer Disease (AD). While individual Aβ-accumulation can be measured non-invasively using Pittsburgh Compund-B positron emission tomography (PiB-PET), Fluid-attenuated inversion recovery (FLAIR) is a Magnetic Resonance Imaging (MRI) sequence, capable of indicating heterogeneous age-related brain pathologies associated with tissue-edema. In the current study cognitively normal elderly subjects were investigated for regional correlation of PiB- and FLAIR intensity. Methods: Fourteen healthy elderly subjects without known history of cognitive impairment received 11C-PiB-PET for estimation of regional Aβ-load. In addition, whole brain T1-MPRAGE and FLAIR-MRI sequences were acquired at high field strength of 7 Tesla (7T). Volume-normalized intensities of brain regions were assessed by applying an automated subcortical segmentation algorithm for spatial definition of brain structures. Statistical dependence between FLAIR- and PiB-PET intensities was tested using Spearman's rank correlation coefficient (rho), followed by Holm–Bonferroni correction for multiple testing. Results: Neuropsychological testing revealed normal cognitive performance levels in all participants. Mean regional PiB-PET and FLAIR intensities were normally distributed and independent. Significant correlation between volume-normalized PiB-PET signals and FLAIR intensities resulted for Hippocampus (right: rho = 0.86; left: rho = 0.84), Brainstem (rho = 0.85) and left Basal Ganglia vessel region (rho = 0.82). Conclusions: Our finding of a significant relationship between PiB- and FLAIR intensity mainly observable in the Hippocampus and Brainstem, indicates regional Aβ associated tissue-edema in cognitively normal elderly subjects. Further studies including clinical populations are necessary to clarify the relevance of our findings for estimating individual risk for age-related neurodegenerative processes such as AD.
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Affiliation(s)
- Simon J Schreiner
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland
| | - Xinyang Liu
- Department of Radiology, Harvard Medical School, Brigham and Women's Hospital Boston, MA, USA
| | - Anton F Gietl
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland
| | - Michael Wyss
- Department of Information Technology and Electrical Engineering, Institute for Biomedical Engineering, University of Zürich and ETH Zürich Zürich, Switzerland
| | - Stefanie C Steininger
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland
| | - Esmeralda Gruber
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland
| | - Valerie Treyer
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland ; Division of Nuclear Medicine, University of Zürich Zürich, Switzerland
| | - Irene B Meier
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland ; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University Medical Center New York, NY, USA
| | - Andrea M Kälin
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland
| | - Sandra E Leh
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland
| | - Alfred Buck
- Division of Nuclear Medicine, University of Zürich Zürich, Switzerland
| | - Roger M Nitsch
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland
| | - Klaas P Pruessmann
- Department of Information Technology and Electrical Engineering, Institute for Biomedical Engineering, University of Zürich and ETH Zürich Zürich, Switzerland
| | - Christoph Hock
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland
| | - Paul G Unschuld
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich Zürich, Switzerland
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Kinner S, Maderwald S, Albert J, Parohl N, Corot C, Robert P, Baba HA, Barkhausen J. Discrimination of benign and malignant lymph nodes at 7.0T compared to 1.5T magnetic resonance imaging using ultrasmall particles of iron oxide: a feasibility preclinical study. Acad Radiol 2013; 20:1604-9. [PMID: 24200489 DOI: 10.1016/j.acra.2013.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 08/31/2013] [Accepted: 09/01/2013] [Indexed: 11/17/2022]
Abstract
RATIONALE AND OBJECTIVES To investigate the feasibility and performance of 7T magnetic resonance imaging compared to 1.5T imaging to discriminate benign (normal and inflammatory changed) from tumor-bearing lymph nodes in rabbits using ultrasmall particles of iron oxide (USPIO)-based contrast agents. MATERIALS AND METHODS Six New Zealand White rabbits were inoculated with either complete Freund's adjuvant cell suspension (n = 3) to induce reactively enlarged lymph nodes or with VX2 tumor cells to produce metastatic lymph nodes (n = 3). Image acquisition was performed before and 24 hours after bolus injection of an USPIO contrast agent at 1.5T and afterward at 7T using T1-weighted and T2*-weighted sequences. Sensitivities, specificities, and negative and positive predictive values for the detection of lymph node metastases were calculated for both field strengths with histopathology serving as reference standard. Sizes of lymph nodes with no, inflammatory, and malignant changes were compared using a Mann-Whitney U-test. RESULTS All 24 lymph nodes were detected at 1.5T as well as at 7T. At 1.5T, sensitivity amounted to 0.67, while specificity reached a value of 1. At the higher field strength (7T), imaging was able to reach sensitivity and specificity values of 1. No statistical differences were detected concerning lymph node sizes. CONCLUSIONS Magnetic resonance lymphography with USPIO contrast agents allows for differentiation of normal and reactively enlarged lymph nodes compared to metastatic nodes. First experiments at 7T show promising results compared to 1.5T, which have to be evaluated in further trials.
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Affiliation(s)
- Sonja Kinner
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45122 Essen, Germany.
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Eggenschwiler F, O'Brien KR, Gruetter R, Marques JP. Improving T2 -weighted imaging at high field through the use of kT -points. Magn Reson Med 2013; 71:1478-88. [PMID: 23788025 DOI: 10.1002/mrm.24805] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 04/16/2013] [Accepted: 04/18/2013] [Indexed: 11/12/2022]
Abstract
PURPOSE At high magnetic field strengths (B(0) ≥ 3 T), the shorter radiofrequency wavelength produces an inhomogeneous distribution of the transmit magnetic field. This can lead to variable contrast across the brain which is particularly pronounced in T(2) -weighted imaging that requires multiple radiofrequency pulses. To obtain T(2) -weighted images with uniform contrast throughout the whole brain at 7 T, short (2-3 ms) 3D tailored radiofrequency pulses (kT -points) were integrated into a 3D variable flip angle turbo spin echo sequence. METHODS The excitation and refocusing "hard" pulses of a variable flip angle turbo spin echo sequence were replaced with kT -point pulses. Spatially resolved extended phase graph simulations and in vivo acquisitions at 7 T, utilizing both single channel and parallel-transmit systems, were used to test different kT -point configurations. RESULTS Simulations indicated that an extended optimized k-space trajectory ensured a more homogeneous signal throughout images. In vivo experiments showed that high quality T(2) -weighted brain images with uniform signal and contrast were obtained at 7 T by using the proposed methodology. CONCLUSION This work demonstrates that T(2) -weighted images devoid of artifacts resulting from B(1)(+) inhomogeneity can be obtained at high field through the optimization of extended kT -point pulses.
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Affiliation(s)
- Florent Eggenschwiler
- Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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41
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Clinical applications of 7T MRI in the brain. Eur J Radiol 2013; 82:708-18. [PMID: 21937178 DOI: 10.1016/j.ejrad.2011.07.007] [Citation(s) in RCA: 163] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 07/12/2011] [Indexed: 11/19/2022]
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den Hartog AG, Bovens SM, Koning W, Hendrikse J, Pasterkamp G, Moll FL, de Borst GJ. PLACD-7T Study: Atherosclerotic Carotid Plaque Components Correlated with Cerebral Damage at 7 Tesla Magnetic Resonance Imaging. Curr Cardiol Rev 2012; 7:28-34. [PMID: 22294972 PMCID: PMC3131713 DOI: 10.2174/157340311795677743] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2010] [Revised: 10/16/2010] [Accepted: 01/07/2011] [Indexed: 11/22/2022] Open
Abstract
Introduction: In patients with carotid artery stenosis histological plaque composition is associated with plaque stability and with presenting symptomatology. Preferentially, plaque vulnerability should be taken into account in pre-operative work-up of patients with severe carotid artery stenosis. However, currently no appropriate and conclusive (non-) invasive technique to differentiate between the high and low risk carotid artery plaque in vivo is available. We propose that 7 Tesla human high resolution MRI scanning will visualize carotid plaque characteristics more precisely and will enable correlation of these specific components with cerebral damage. Study objective: The aim of the PlaCD-7T study is 1: to correlate 7T imaging with carotid plaque histology (gold standard); and 2: to correlate plaque characteristics with cerebral damage ((clinically silent) cerebral (micro) infarcts or bleeds) on 7 Tesla high resolution (HR) MRI. Design: We propose a single center prospective study for either symptomatic or asymptomatic patients with haemodynamic significant (70%) stenosis of at least one of the carotid arteries. The Athero-Express (AE) biobank histological analysis will be derived according to standard protocol. Patients included in the AE and our prospective study will undergo a pre-operative 7 Tesla HR-MRI scan of both the head and neck area. Discussion: We hypothesize that the 7 Tesla MRI scanner will allow early identification of high risk carotid plaques being associated with micro infarcted cerebral areas, and will thus be able to identify patients with a high risk of periprocedural stroke, by identification of surrogate measures of increased cardiovascular risk.
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Affiliation(s)
- A G den Hartog
- Departments of Vascular Surgery, Utrecht, the Netherlands, Interuniversity Cardiology Institute of the Netherlands (ICIN), Utrecht, The Netherlands
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Wattjes MP, Barkhof F. Diagnostic relevance of high field MRI in clinical neuroradiology: the advantages and challenges of driving a sports car. Eur Radiol 2012; 22:2304-6. [PMID: 22821393 PMCID: PMC3472049 DOI: 10.1007/s00330-012-2552-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 06/06/2012] [Accepted: 06/11/2012] [Indexed: 11/04/2022]
Abstract
Abstract High field MRI operating at 3 T is increasingly being used in the field of neuroradiology on the grounds that higher magnetic field strength should theoretically lead to a higher diagnostic accuracy in the diagnosis of several disease entities. This Editorial discusses the exhaustive review by Wardlaw and colleagues of research comparing 3 T MRI with 1.5 T MRI in the field of neuroradiology. Interestingly, the authors found no convincing evidence of improved image quality, diagnostic accuracy, or reduced total examination times using 3 T MRI instead of 1.5 T MRI. These findings are highly relevant since a new generation of high field MRI systems operating at 7 T has recently been introduced. Key Points • Higher magnetic field strengths do not necessarily lead to a better diagnostic accuracy. • Disadvantages of high field MR systems have to be considered in clinical practice. • Higher field strengths are needed for functional imaging, spectroscopy, etc. • Disappointingly there are few direct comparisons of 1.5 and 3 T MRI. • Whether the next high field MR generation (7 T) will improve diagnostic accuracy has to be investigated.
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Affiliation(s)
- Mike P Wattjes
- Department of Radiology, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
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Moser E, Stahlberg F, Ladd ME, Trattnig S. 7-T MR--from research to clinical applications? NMR IN BIOMEDICINE 2012; 25:695-716. [PMID: 22102481 DOI: 10.1002/nbm.1794] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 08/25/2011] [Accepted: 08/31/2011] [Indexed: 05/31/2023]
Abstract
Over 20,000 MR systems are currently installed worldwide and, although the majority operate at magnetic fields of 1.5 T and below (i.e. about 70%), experience with 3-T (in high-field clinical diagnostic imaging and research) and 7-T (research only) human MR scanners points to a future in functional and metabolic MR diagnostics. Complementary to previous studies, this review attempts to provide an overview of ultrahigh-field MR research with special emphasis on emerging clinical applications at 7 T. We provide a short summary of the technical development and the current status of installed MR systems. The advantages and challenges of ultrahigh-field MRI and MRS are discussed with special emphasis on radiofrequency inhomogeneity, relaxation times, signal-to-noise improvements, susceptibility effects, chemical shifts, specific absorption rate and other safety issues. In terms of applications, we focus on the topics most likely to gain significantly from 7-T MR, i.e. brain imaging and spectroscopy and musculoskeletal imaging, but also body imaging, which is particularly challenging. Examples are given to demonstrate the advantages of susceptibility-weighted imaging, time-of-flight MR angiography, high-resolution functional MRI, (1)H and (31)P MRSI in the human brain, sodium and functional imaging of cartilage and the first results (and artefacts) using an eight-channel body array, suggesting future areas of research that should be intensified in order to fully explore the potential of 7-T MR systems for use in clinical diagnosis.
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Affiliation(s)
- Ewald Moser
- Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
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Zwanenburg JJM, Hendrikse J, Luijten PR. Generalized multiple-layer appearance of the cerebral cortex with 3D FLAIR 7.0-T MR imaging. Radiology 2012; 262:995-1001. [PMID: 22357899 DOI: 10.1148/radiol.11110812] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To examine the multiple-layer appearance of the cerebral cortex with fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) imaging at 7.0 T, whole-brain volumetric three-dimensional (3D) magnetization prepared FLAIR images were acquired in 12 volunteers (0.8 3 0.8 3 0.8-mm spatial resolution). Signal intensity profiles were evaluated for the anterior frontal (Brodmann area [BA] 10), posterior frontal (BA 6), parietal (BA 7), precentral (BA 4), postcentral (BA 3), occipital (BA 18), and calcarine (BA 17) regions. Variance of the normalized profile was used as the metric for the multiple-layer appearance. Wilcoxon signed-rank tests were performed to compare variances of the profiles between all areas. All cortical areas showed multiple-layered appearances, with a prominent hyperintense band at the external surface of the cortex, a hypointense band deeper in the cortex, and a hyperintense third band. The ranking from least- to most-pronounced layer appearance was as follows: postcentral (variance, 0.04), posterior frontal (variance, 0.05), calcarine (variance, 0.05), precentral (variance, 0.06), parietal (variance, 0.08), anterior frontal (variance, 0.10), and occipital (variance, 0.11). Each region was significantly different from at least one other region. In conclusion, a multiple-layer appearance of the cerebral cortex was found for all cortical regions with high-spatial-resolution 3D FLAIR MR imaging at 7.0 T.
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Affiliation(s)
- Jaco J M Zwanenburg
- Department of Radiology, University Medical Center Utrecht, HP E 01.132, PO Box 85500, 3508 GA Utrecht, the Netherlands.
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Versluis MJ, van der Grond J, van Buchem MA, van Zijl P, Webb AG. High-field imaging of neurodegenerative diseases. Neuroimaging Clin N Am 2012; 22:159-71, ix. [PMID: 22548926 DOI: 10.1016/j.nic.2012.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
High-field magnetic resonance (MR) imaging is showing potential for imaging of neurodegenerative diseases. 7 T MR imaging is beginning to be used in a clinical research setting and the theoretical benefits of higher signal-to-noise ratio, sensitivity to iron, improved MR angiography, and increased spectral resolution in spectroscopy are being confirmed. Despite the limited number of studies to date, initial results in patients with multiple sclerosis, Alzheimer disease, and Huntington disease show promising additional features in contrast that may help the diagnosis of these disorders.
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Affiliation(s)
- M J Versluis
- Department of Radiology, C.J. Gorter Center for High Field MR, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
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Advances in ultra-high field MRI for the clinical management of patients with brain tumors. Curr Opin Neurol 2012; 24:605-15. [PMID: 22045220 DOI: 10.1097/wco.0b013e32834cd495] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
PURPOSE OF REVIEW The last 5 years have seen the number of ultra-high field (UHF; 7 T and beyond) MRI scanners nearly double. Benefits include improved specificity, better sensitivity for signal-starved compounds, and the ability to detect, quantify, and monitor tumor activity and treatment effects. This is especially important in the current climate in which new treatments alter established markers of tumor and the surrounding environment, confounding traditional response criteria. RECENT FINDINGS Intra-tumoral heterogeneity and dramatic improvement in spatial localization have been observed with 7 and 8 T high-resolution T2-weighted and T2*-weighted imaging. This depiction of lesions that were not readily detected at lower field improved the classification of glioma. Sub-millimeter visualization of microvasculature has facilitated the detection of microbleeds associated with long-term effects of radiation. New metabolic markers seen at UHF may also assist in distinguishing tumor progression from treatment effect. SUMMARY Although progress has been limited by technical challenges, initial experience has demonstrated the promise of 7-T MRI in advancing existing paradigms for diagnosing, monitoring, and managing patients with brain tumors. The success of these systems will depend upon what new information can be gained by UHF, rather than simply improving the quality of the current lower field standard.
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Grabner G, Nöbauer I, Elandt K, Kronnerwetter C, Woehrer A, Marosi C, Prayer D, Trattnig S, Preusser M. Longitudinal brain imaging of five malignant glioma patients treated with bevacizumab using susceptibility-weighted magnetic resonance imaging at 7 T. Magn Reson Imaging 2011; 30:139-47. [PMID: 21982163 DOI: 10.1016/j.mri.2011.08.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 08/04/2011] [Indexed: 11/26/2022]
Abstract
Malignant glioma is a rare tumor type characterized by prominent vascular proliferation. Antiangiogenic therapy with the monoclonal antibody bevacizumab is considered as a promising therapeutic strategy, although the effect on tumor vascularization is unclear. High-field susceptibility-weighted imaging (SWI) visualizes the microvasculature and may contribute to the investigation of antiangiogenic therapy responses in gliomas. We prospectively studied five adult malignant glioma patients treated with bevacizumab-containing regimens. In each patient, we performed three 7-T SWI and T1-weighted imaging investigations (baseline and 2 and 4 weeks after the start of bevacizumab treatment). In addition, we imaged a postmortem brain of a patient with glioblastoma using 7-T SWI and performed detailed histopathological analysis. We observed almost total resolution of brain edema in three of five patients after initiation of bevacizumab therapy. In one case with rapid increase of the lesion size despite bevacizumab therapy, SWI showed progressive increase of irregular hypointense structures, most likely corresponding to increasing amounts of pathological microvasculature. In one case with progressive neurological decline, 7-T images showed multiple intratumoral microhemorrhages after the first bevacizumab application. Correlation of postmortem neuroimaging with histopathology confirmed that SWI-positive structures correspond to tumor vasculature. The experience from our case series indicates that longitudinal 7-T SWI seems to be an appropriate method for investigation of changes in brain tumor vascularization over time under antiangiogenic therapy.
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Affiliation(s)
- Günther Grabner
- Department of Radiology, Medical University of Vienna, A-1090 Vienna, Austria
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Lesion detection at seven Tesla in multiple sclerosis using magnetisation prepared 3D-FLAIR and 3D-DIR. Eur Radiol 2011; 22:221-31. [PMID: 21874361 PMCID: PMC3229693 DOI: 10.1007/s00330-011-2242-z] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 06/27/2011] [Accepted: 07/06/2011] [Indexed: 01/11/2023]
Abstract
Objectives To examine the feasibility and value of 7 T 3D T2-weighted Fluid Attenuated Inversion Recovery (FLAIR) and Double Inversion Recovery (DIR) MR sequences for lesion detection in multiple sclerosis (MS). Methods High-resolution 3D-FLAIR and 3D-DIR MR sequences at 7 T were obtained using magnetisation preparation (MP), and compared with 2D-T2-weighted and 3D-T1-weighted sequences in 10 MS patients and five healthy controls. We determined contrast ratios and counted lesions according to anatomical location. Results MR imaging at 7 T was safe and allowed multi-contrast imaging within clinically acceptable imaging times. Lesion to white matter (WM) and grey matter (GM) contrast ratios were higher in 3D-MP-FLAIR and 3D-MP-DIR compared with 2D-T2 and 3D-T1. Cortical (mixed+intra-cortical) and total lesion counts were 97/592 on 3D-MP-FLAIR and 100/558 on 3D-MP-DIR compared with 84/384 on 2D-T2 and 42/442 on 3D-T1. More juxta-cortical lesions were seen with 3D-MP-FLAIR (205) and 3D-MP-DIR (133) than with 2D-T2 (125) and 3D-T1 (70). Finally, higher numbers of lesions were found for deep WM lesions: 176 for 3D-MP-FLAIR and 196 for 3D-MP-DIR vs. 155 for 2D-T2 and 131 for 3D-T1. Conclusions Near isotropic 3D-MP-FLAIR and 3D-MP-DIR allows high quality T2-weighted MR imaging in MS at 7 T, improving (cortical) lesion detection. Key Points • Magnetization prepared 3D-FLAIR and 3D-DIR 7 T MRI provide high quality isotropic images. • MS lesions are well demonstrated by 3D-MP-FLAIR and 3D-MP-DIR at 7 T MRI. • 3D-MP-FLAIR and 3D-MP-DIR at 7 T MRI show many more Virchov-Robin spaces.
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Polders DL, Leemans A, Hendrikse J, Donahue MJ, Luijten PR, Hoogduin JM. Signal to noise ratio and uncertainty in diffusion tensor imaging at 1.5, 3.0, and 7.0 Tesla. J Magn Reson Imaging 2011; 33:1456-63. [DOI: 10.1002/jmri.22554] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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