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Morrison MA, Lupo JM. 7-T Magnetic Resonance Imaging in the Management of Brain Tumors. Magn Reson Imaging Clin N Am 2021; 29:83-102. [PMID: 33237018 DOI: 10.1016/j.mric.2020.09.007] [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] [Indexed: 12/13/2022]
Abstract
This article provides an overview of the current status of ultrahigh-field 7-T magnetic resonance (MR) imaging in neuro-oncology, specifically for the management of patients with brain tumors. It includes a discussion of areas across the pretherapeutic, peritherapeutic, and posttherapeutic stages of patient care where 7-T MR imaging is currently being exploited and holds promise. This discussion includes existing technical challenges, barriers to clinical integration, as well as our impression of the future role of 7-T MR imaging as a clinical tool in neuro-oncology.
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Affiliation(s)
- Melanie A Morrison
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143, USA
| | - Janine M Lupo
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143, USA.
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Debnath A, Gupta RK, Reddy R, Singh A. Effect of offset-frequency step size and interpolation methods on chemical exchange saturation transfer MRI computation in human brain. NMR IN BIOMEDICINE 2021; 34:e4468. [PMID: 33543519 DOI: 10.1002/nbm.4468] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Chemical exchange saturation transfer (CEST) MRI is a non-invasive molecular imaging technique with potential applications in pre-clinical and clinical studies. Applications of amide proton transfer-weighted (APT-w), glutamate-weighted (Glu-w) and creatine-weighted (Cr-w) CEST, among others, have been reported. In general, CEST data are acquired at multiple offset-frequencies. In reported studies, different offset-frequency step sizes and interpolation methods have been used during B0 inhomogeneity correction of data. The objective of the current study was to evaluate the effects of different step sizes and interpolation methods on CEST value computation. In the current study, simulation (Glu-w, Cr-w and APT-w) and experimental data from the brain were used. Experimental CEST data (Glu-w) were acquired from human volunteers at 7 T and brain tumor patients (APT-w) at 3 T. During B0 inhomogeneity correction, different interpolation methods (polynomial [degree-1, 2 and 3], cubic-Hermite, cubic-spline and smoothing-spline) were compared. CEST values were computed using asymmetry analysis. The effects of different step sizes and interpolation methods were evaluated using coefficient of variation (CV), normalized mean square error (nMSE) and coefficient of correlation parameters. Additionally, an optimum interpolation method for APT-w values was selected based upon fitting accuracy, T-test, receiver operating characteristic analysis, and its diagnostic performance in differentiating low-grade and high-grade tumors. CV and nMSE increase with an increase in step size irrespective of the interpolation method (except for cubic-Hermite and cubic-spline). The nMSE of Cr-w and Glu-w CEST values were least for polynomial (degree-2 and 3). The quality of Glu-w CEST maps became coarse with the increase in step size. There was a significant difference (P < .05) between low-grade and high-grade tumors using polynomial interpolation (degree-1, 2 and 3); however, linear interpolation outperforms other methods for APT-w data, providing the highest sensitivity and specificity. In conclusion, depending upon the saturation parameters and field strength, optimization of step size and interpolation should be carried out for different CEST metabolites/molecules. Glu-w, Cr-w and APT-w CEST data should be acquired with a step size of between 0.2 and 0.3 ppm. For B0 inhomogeneity correction, polynomial (degree-2) should be used for Glu-w and Cr-w CEST data at 7 T and linear interpolation should be used for APT-w data at 3 T for a limited frequency range.
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Affiliation(s)
- Ayan Debnath
- Center for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India
- CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Ravinder Reddy
- CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anup Singh
- Center for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India
- All India Institute of Medical Science, Delhi, India
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Wu Y, Chen Y, Zhao Y, Yang S, Zhao J, Zhou J, Chen Z, Sun PZ, Zheng H. Direct radiofrequency saturation corrected amide proton transfer tumor MRI at 3T. Magn Reson Med 2018; 81:2710-2719. [DOI: 10.1002/mrm.27562] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/13/2018] [Accepted: 09/16/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Yin Wu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen Guangdong China
| | - Yinsheng Chen
- Department of Neurosurgery Cancer Center, Sun Yat‐Sen University Guangzhou Guangdong China
| | - Yiying Zhao
- Department of Neurosurgery Cancer Center, Sun Yat‐Sen University Guangzhou Guangdong China
| | - Shasha Yang
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen Guangdong China
| | - Jing Zhao
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen Guangdong China
| | - Jian Zhou
- Department of Medical Imaging Cancer Center, Sun Yat‐Sen University Guangzhou Guangdong China
| | - Zhongping Chen
- Department of Neurosurgery Cancer Center, Sun Yat‐Sen University Guangzhou Guangdong China
| | - Phillip Zhe Sun
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology Massachusetts General Hospital and Harvard Medical School Charlestown Massachusetts
- Yerkes Imaging Center Yerkes National Primate Research Center, Emory University Atlanta Georgia
- Department of Radiology Emory University School of Medicine Atlanta Georgia
| | - Hairong Zheng
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen Guangdong China
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Zhou IY, Wang E, Cheung JS, Lu D, Ji Y, Zhang X, Fulci G, Sun PZ. Direct saturation-corrected chemical exchange saturation transfer MRI of glioma: Simplified decoupling of amide proton transfer and nuclear overhauser effect contrasts. Magn Reson Med 2017; 78:2307-2314. [PMID: 29030880 PMCID: PMC5744877 DOI: 10.1002/mrm.26959] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/15/2017] [Accepted: 09/16/2017] [Indexed: 12/27/2022]
Abstract
PURPOSE Chemical exchange saturation transfer (CEST) MRI has shown promise in tissue characterization in diseases like stroke and tumor. However, in vivo CEST imaging such as amide proton transfer (APT) MRI is challenging because of concomitant factors such as direct water saturation, macromolecular magnetization transfer, and nuclear overhauser effect (NOE), which lead to a complex contrast in the commonly used asymmetry analysis (MTRasym). Here, we propose a direct saturation-corrected CEST (DISC-CEST) analysis for simplified decoupling and quantification of in vivo CEST effects. METHODS CEST MRI and relaxation measurements were carried out on a classical 2-pool creatine-gel CEST phantom and normal rat brains (N = 6) and a rat model of glioma (N = 8) at 4.7T. The proposed DISC-CEST quantification was carried out and compared with conventional MTRasym and the original three-offset method. RESULTS We demonstrated that the DISC-CEST contrast in the phantom had much stronger correlation with MTRasym than the three-offset method, which showed substantial underestimation. In normal rat brains, the DISC-CEST approach revealed significantly stronger APT effect in gray matter and higher NOE effect in white matter. Furthermore, the APT and NOE maps derived from DISC-CEST showed significantly higher APT effect in the tumors than contralateral normal tissue but no apparent difference in NOE. CONCLUSION The proposed DISC-CEST method, by correction of nonlinear direct water saturation effect, serves as a promising alternative to both the commonly used MTRasym and the simplistic three-offset analyses. It provides simple yet reliable in vivo CEST quantification such as APT and NOE mapping in brain tumor, which is promising for clinical translation. Magn Reson Med 78:2307-2314, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Iris Yuwen Zhou
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Enfeng Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
- Department of Radiology, 3 Affiliated Hospital, Zhengzhou University, Henan, China
| | - Jerry S Cheung
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Dongshuang Lu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Yang Ji
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Xiaoan Zhang
- Department of Radiology, 3 Affiliated Hospital, Zhengzhou University, Henan, China
| | - Giulia Fulci
- Molecular Neuro-oncology Laboratories, Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02124, USA
| | - Phillip Zhe Sun
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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Wang Y, Zhang Y, Zhao X, Wu B, Gao JH. Perturbation of longitudinal relaxation rate in rotating frame (PLRF) analysis for quantification of chemical exchange saturation transfer signal in a transient state. Magn Reson Med 2016; 78:1711-1723. [PMID: 27888530 DOI: 10.1002/mrm.26559] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/03/2016] [Accepted: 10/29/2016] [Indexed: 11/06/2022]
Abstract
PURPOSE To develop a novel analytical method for quantification of chemical exchange saturation transfer (CEST) in the transient state. The proposed method aims to reduce the effects of non-chemical-exchange (non-CE) parameters on the CEST signal, emphasizing the effect of chemical exchange. METHODS The difference in the longitudinal relaxation rate in the rotating frame ( ΔR1ρ) was calculated based on perturbation of the Z-value by R1ρ, and a saturation-pulse-amplitude-compensated exchange-dependent relaxation rate (SPACER) was determined with a high-exchange-rate approximation. In both phantom and human subject experiments, MTRasym (representative of the traditional CEST index), ΔR1ρ, and SPACER were measured, evaluated, and compared by altering the non-CE parameters in a transient-state continuous-wave CEST sequence. RESULTS In line with the theoretical expectation, our experimental data demonstrate that the effects of the non-CE parameters can be more effectively reduced using the proposed indices ( ΔR1ρ and SPACER) than using the traditional CEST index ( MTRasym). CONCLUSION The proposed method allows for the chemical exchange weight to be better emphasized in the transient-state CEST signal, which is beneficial, in practice, for quantifying the CEST signal. Magn Reson Med 78:1711-1723, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Yi Wang
- Beijing City Key Lab for Medical Physics and Engineering, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing, China.,Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Yaoyu Zhang
- Beijing City Key Lab for Medical Physics and Engineering, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing, China.,Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Xuna Zhao
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Bing Wu
- GE Healthcare China, Beijing, China
| | - Jia-Hong Gao
- Beijing City Key Lab for Medical Physics and Engineering, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing, China.,Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,McGovern Institute for Brain Research, Peking University, Beijing, China
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Liu Z, Dimitrov IE, Lenkinski RE, Hajibeigi A, Vinogradov E. UCEPR: Ultrafast localized CEST-spectroscopy with PRESS in phantoms and in vivo. Magn Reson Med 2016; 75:1875-85. [PMID: 26033357 PMCID: PMC4663188 DOI: 10.1002/mrm.25780] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/02/2015] [Accepted: 04/27/2015] [Indexed: 11/10/2022]
Abstract
PURPOSE Chemical exchange saturation transfer (CEST) is a contrast mechanism enhancing low-concentration molecules through saturation transfer from their exchangeable protons to bulk water. Often many scans are acquired to form a Z-spectrum, making the CEST method time-consuming. Here, an ultrafast localized CEST-spectroscopy with PRESS (UCEPR) is proposed to obtain the entire Z-spectrum of a voxel using only two scans, significantly accelerating CEST. THEORY AND METHODS The approach combines ultrafast nonlocalized CEST spectroscopy with localization using PRESS. A field gradient is applied concurrently with the saturation pulse producing simultaneous saturation of all Z-spectrum frequencies that are also spatially encoded. A readout gradient during data acquisition resolves the spatial dependence of the CEST responses into frequency. UCEPR was tested on a 3T scanner both in phantoms and in vivo. RESULTS In phantoms, a fast Z-spectroscopy acquisition of multiple pH-variant iopamidol samples was achieved with four- to seven-fold acceleration as compared to the conventional CEST methods. In vivo, amide proton transfer (APT) in white matter of healthy human brain was measured rapidly in 48 s and with high frequency resolution (≤ 0.2 ppm). CONCLUSION Compared with conventional CEST methods, UCEPR has the advantage of rapidly acquiring high-resolution Z-spectra. Potential in vivo applications include ultrafast localized Z-spectroscopy, quantitative, or dynamic CEST studies.
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Affiliation(s)
- Zheng Liu
- Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Ivan E. Dimitrov
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Philips Medical Systems, Highland Heights, Ohio, USA
| | - Robert E. Lenkinski
- Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Asghar Hajibeigi
- Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Elena Vinogradov
- Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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