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Bie C, van Zijl P, Xu J, Song X, Yadav NN. Radiofrequency labeling strategies in chemical exchange saturation transfer MRI. NMR IN BIOMEDICINE 2023; 36:e4944. [PMID: 37002814 PMCID: PMC10312378 DOI: 10.1002/nbm.4944] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 03/19/2023] [Accepted: 03/27/2023] [Indexed: 05/23/2023]
Abstract
Chemical exchange saturation transfer (CEST) MRI has generated great interest for molecular imaging applications because it can image low-concentration solute molecules in vivo with enhanced sensitivity. CEST effects are detected indirectly through a reduction in the bulk water signal after repeated perturbation of the solute proton magnetization using one or more radiofrequency (RF) irradiation pulses. The parameters used for these RF pulses-frequency offset, duration, shape, strength, phase, and interpulse spacing-determine molecular specificity and detection sensitivity, thus their judicious selection is critical for successful CEST MRI scans. This review article describes the effects of applying RF pulses on spin systems and compares conventional saturation-based RF labeling with more recent excitation-based approaches that provide spectral editing capabilities for selectively detecting molecules of interest and obtaining maximal contrast.
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Affiliation(s)
- Chongxue Bie
- Department of Information Science and Technology, Northwest University, No.1 Xuefu Avenue, Xi’an, Shaanxi 710127 (China)
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N. Broadway, Baltimore MD 21205 (USA)
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 720 Rutland Ave, Baltimore, MD 21205 (USA)
| | - Peter van Zijl
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N. Broadway, Baltimore MD 21205 (USA)
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 720 Rutland Ave, Baltimore, MD 21205 (USA)
| | - Jiadi Xu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N. Broadway, Baltimore MD 21205 (USA)
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 720 Rutland Ave, Baltimore, MD 21205 (USA)
| | - Xiaolei Song
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Haidian District, Beijing 100084 (China)
| | - Nirbhay N. Yadav
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N. Broadway, Baltimore MD 21205 (USA)
- The Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, 720 Rutland Ave, Baltimore, MD 21205 (USA)
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Tang X, Zhang H, Zhou J, Kang H, Yang S, Cui H, Peng Y. Brain development in children with developmental delay using amide proton transfer-weighted imaging and magnetization transfer imaging. Pediatr Investig 2020; 4:250-256. [PMID: 33376952 PMCID: PMC7768295 DOI: 10.1002/ped4.12237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 06/02/2020] [Indexed: 11/09/2022] Open
Abstract
IMPORTANCE The process of brain development in children with developmental delay is not well known. Amide proton transfer-weighted (APTw) imaging is a novel molecular magnetic resonance imaging (MRI) technique that can noninvasively detect cytosolic endogenous mobile proteins and peptides involved in the myelination process, and may be useful for providing insights into brain development. OBJECTIVE To assess the contribution of amide proton transfer-weighted (APTw) imaging and magnetization transfer (MT) imaging to the evaluation of children with developmental delay (DD). METHODS Fifty-one patients with DD were recruited to this study. The patients were divided into two groups according to the state of myelination assessed on conventional magnetic resonance imaging (MRI). Thirty patients (10 girls, 20 boys; age range: 1-8 months; median age: 4 months) in group A showed delayed myelination on MRI, while 21 patients (3 girls, 18 boys; age range: 12-36months; median age: 25months) in group B showed normal myelination on MRI. Fifty-one age- and sex-matched children with normal developmental quotient (DQ) and normal MRI appearance were recruited as normal controls. Three-slice APTw/MT axial imaging was performed at the level of the centrum semiovale, the basal ganglia and the pons. Quantitative data of the MT ratio (MTR) and APTw were analyzed for multiple brain regions. Independent-sample t-tests were used to compare differences in APTw and MTR signals between the two DD groups and normal controls. Analysis of Covariance was conducted to correct the statistical results. The level of statistical significance was set to P < 0.05. RESULTS For group A, the MTR values were lower in all regions (P = 0.004-0.033) compared with the normal controls, while the APTw values were higher in the pons, middle cerebellar peduncle, corpus callosum, frontal white matter, occipital white matter and centrum semiovale (P = 0.004-0.040 ). For Group B, the MTR values were slightly reduced, and the APTw values were slightly increased compared with the normal controls, but the differences were not statistically significant (P > 0.05). INTERPRETATION For DD patients showing signs of delayed myelination on MRI, MTR and APTw imaging can help to diagnose myelination delay by quantifying semi-solid macromolecules and cytosolic endogenous mobile proteins and peptides at a molecular level, providing a new method for comprehensive evaluation of DD. For DD patients with normal myelination on MRI, the clinical values of MTR and APTw imaging remain to be explored.
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Affiliation(s)
- Xiaolu Tang
- Imaging CenterBeijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijingChina
| | - Hong Zhang
- Imaging CenterBeijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijingChina
| | - Jinyuan Zhou
- Division of MR ResearchDepartment of RadiologyJohns Hopkins UniversityBaltimoreMDUSA
| | - Huiying Kang
- Imaging CenterBeijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijingChina
| | - Shuangfeng Yang
- Imaging CenterBeijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijingChina
| | - Haijing Cui
- Rehabilitation DepartmentBeijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijingChina
| | - Yun Peng
- Imaging CenterBeijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijingChina
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Demetriou E, Kujawa A, Golay X. Pulse sequences for measuring exchange rates between proton species: From unlocalised NMR spectroscopy to chemical exchange saturation transfer imaging. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2020; 120-121:25-71. [PMID: 33198968 DOI: 10.1016/j.pnmrs.2020.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 06/27/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
Within the field of NMR spectroscopy, the study of chemical exchange processes through saturation transfer techniques has a long history. In the context of MRI, chemical exchange techniques have been adapted to increase the sensitivity of imaging to small fractions of exchangeable protons, including the labile protons of amines, amides and hydroxyls. The MR contrast is generated by frequency-selective irradiation of the labile protons, which results in a reduction of the water signal associated with transfer of the labile protons' saturated magnetization to the protons of the surrounding free water. The signal intensity depends on the rate of chemical exchange and the concentration of labile protons as well as on the properties of the irradiation field. This methodology is referred to as CEST (chemical exchange saturation transfer) imaging. Applications of CEST include imaging of molecules with short transverse relaxation times and mapping of physiological parameters such as pH, temperature, buffer concentration and chemical composition due to the dependency of this chemical exchange effect on all these parameters. This article aims to describe these effects both theoretically and experimentally. In depth analysis and mathematical modelling are provided for all pulse sequences designed to date to measure the chemical exchange rate. Importantly, it has become clear that the background signal from semi-solid protons and the presence of the Nuclear Overhauser Effect (NOE), either through direct dipole-dipole mechanisms or through exchange-relayed signals, complicates the analysis of CEST effects. Therefore, advanced methods to suppress these confounding factors have been developed, and these are also reviewed. Finally, the experimental work conducted both in vitro and in vivo is discussed and the progress of CEST imaging towards clinical practice is presented.
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Affiliation(s)
- Eleni Demetriou
- Brain Repair & Rehabilitation, Institute of Neurology, University College London, United Kingdom.
| | - Aaron Kujawa
- Brain Repair & Rehabilitation, Institute of Neurology, University College London, United Kingdom.
| | - Xavier Golay
- Brain Repair & Rehabilitation, Institute of Neurology, University College London, United Kingdom.
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Amide Proton Transfer-Weighted (APTw) Imaging of Intracranial Infection in Children: Initial Experience and Comparison with Gadolinium-Enhanced T1-Weighted Imaging. BIOMED RESEARCH INTERNATIONAL 2020; 2020:6418343. [PMID: 32509865 PMCID: PMC7251435 DOI: 10.1155/2020/6418343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 03/21/2020] [Accepted: 04/25/2020] [Indexed: 12/05/2022]
Abstract
Purpose To evaluate the performance of amide proton transfer-weighted (APTw) imaging against the reference standard of gadolinium-enhanced T1-weighted imaging (Gd-T1w) in children with intracranial infection. Materials and Methods Twenty-eight pediatric patients (15 males and 13 females; age range 1-163 months) with intracranial infection were recruited in this study. 2D APTw imaging and conventional MR sequences were conducted using a 3 T MRI scanner. Kappa (κ) statistics and the McNemar test were performed to determine whether the hyperintensity on APTw was related to the enhancement on Gd-T1w. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of APTw imaging to predict lesion enhancement were calculated. Result In twelve patients with brain abscesses, the enhancing rim of the abscesses on the Gd-T1w images was consistently hyperintense on the APTw images. In eight patients with viral encephalitis, three showed slight spotted gadolinium enhancement, while the APTw image also showed a slight spotted high signal. Five of these patients showed no enhancement on Gd-T1w and isointensity on the APTw image. In eleven patients with meningitis, increased APTw signal intensities were clearly visible in gadolinium-enhancing meninges. Sixty infectious lesions (71%) showed enhancement on Gd-T1w images. The sensitivity and specificity of APTw were 93.3% (56/60) and 91.7% (22/24). APTw demonstrated excellent agreement (κ = 0.83) with Gd-T1w, with no significant difference (P = 0.69) in detection of infectious lesions. Conclusions These initial data show that APTw MRI is a noninvasive technique for the detection and characterization of intracranial infectious lesions. APTw MRI enabled similar detection of infectious lesions to Gd-T1w and may provide an injection-free means of evaluation of intracranial infection.
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Zhou J, Heo HY, Knutsson L, van Zijl PCM, Jiang S. APT-weighted MRI: Techniques, current neuro applications, and challenging issues. J Magn Reson Imaging 2019; 50:347-364. [PMID: 30663162 DOI: 10.1002/jmri.26645] [Citation(s) in RCA: 252] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 12/26/2018] [Accepted: 12/27/2018] [Indexed: 02/06/2023] Open
Abstract
Amide proton transfer-weighted (APTw) imaging is a molecular MRI technique that generates image contrast based predominantly on the amide protons in mobile cellular proteins and peptides that are endogenous in tissue. This technique, the most studied type of chemical exchange saturation transfer imaging, has been used successfully for imaging of protein content and pH, the latter being possible due to the strong dependence of the amide proton exchange rate on pH. In this article we briefly review the basic principles and recent technical advances of APTw imaging, which is showing promise clinically, especially for characterizing brain tumors and distinguishing recurrent tumor from treatment effects. Early applications of this approach to stroke, Alzheimer's disease, Parkinson's disease, multiple sclerosis, and traumatic brain injury are also illustrated. Finally, we outline the technical challenges for clinical APT-based imaging and discuss several controversies regarding the origin of APTw imaging signals in vivo. Level of Evidence: 3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;50:347-364.
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Affiliation(s)
- Jinyuan Zhou
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Hye-Young Heo
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Linda Knutsson
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Peter C M van Zijl
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Shanshan Jiang
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
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Discriminating MGMT promoter methylation status in patients with glioblastoma employing amide proton transfer-weighted MRI metrics. Eur Radiol 2017; 28:2115-2123. [PMID: 29234914 DOI: 10.1007/s00330-017-5182-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/30/2017] [Accepted: 11/06/2017] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To explore the feasibility of using amide proton transfer-weighted (APTw) MRI metrics as surrogate biomarkers to identify the O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in glioblastoma (GBM). METHODS Eighteen newly diagnosed GBM patients, who were previously scanned at 3T and had a confirmed MGMT methylation status, were retrospectively analysed. For each case, a histogram analysis in the tumour mass was performed to evaluate several quantitative APTw MRI metrics. The Mann-Whitney test was used to evaluate the difference in APTw parameters between MGMT methylated and unmethylated GBMs, and the receiver-operator-characteristic analysis was further used to assess diagnostic performance. RESULTS Ten GBMs were found to harbour a methylated MGMT promoter, and eight GBMs were unmethylated. The mean, variance, 50th percentile, 90th percentile and Width10-90 APTw values were significantly higher in the MGMT unmethylated GBMs than in the MGMT methylated GBMs, with areas under the receiver-operator-characteristic curves of 0.825, 0.837, 0.850, 0856 and 0.763, respectively, for the discrimination of MGMT promoter methylation status. CONCLUSIONS APTw signal metrics have the potential to serve as valuable imaging biomarkers for identifying MGMT methylation status in the GBM population. KEY POINTS • APTw-MRI is applied to predict MGMT promoter methylation status in GBMs. • GBMs with unmethylated MGMT promoter present higher APTw-MRI than methylated GBMs. • Multiple APTw histogram metrics can identify MGMT methylation status. • Mean APTw values showed the highest diagnostic accuracy (AUC = 0.825).
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Lee JS, Regatte RR, Jerschow A. Magnetization transfer in a partly deuterated lyotropic liquid crystal by single- and dual-frequency RF irradiations. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 281:141-150. [PMID: 28595121 PMCID: PMC5537047 DOI: 10.1016/j.jmr.2017.05.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 05/26/2017] [Accepted: 05/29/2017] [Indexed: 05/08/2023]
Abstract
The mechanism of magnetization transfer (MT) in a lyotropic liquid crystal made of sodium dodecyl sulfate, decanol, and water molecules is investigated by using deuterated molecules and single- and dual-frequency RF irradiations. The resulting Z-spectra suggest that the decanol molecules are mainly responsible for the MT effects in this system, through proton exchange to water. This is further confirmed by monitoring the relaxation of dipolar order, which allows one to estimate the transfer rate of magnetization from decanol to water. The potential benefits of using dual-frequency RF irradiation for inducing MT effects are explored through numerical solutions to a MT model based on Provotorov's partial saturation theory.
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Affiliation(s)
- Jae-Seung Lee
- Department of Radiology, New York University Langone Medical Center, New York, NY 10016, USA; Department of Chemistry, New York University, New York, NY 10003, USA.
| | - Ravinder R Regatte
- Department of Radiology, New York University Langone Medical Center, New York, NY 10016, USA
| | - Alexej Jerschow
- Department of Chemistry, New York University, New York, NY 10003, USA
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Jiang S, Zou T, Eberhart CG, Villalobos MAV, Heo HY, Zhang Y, Wang Y, Wang X, Yu H, Du Y, van Zijl PCM, Wen Z, Zhou J. Predicting IDH mutation status in grade II gliomas using amide proton transfer-weighted (APTw) MRI. Magn Reson Med 2017; 78:1100-1109. [PMID: 28714279 DOI: 10.1002/mrm.26820] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/31/2017] [Accepted: 06/11/2017] [Indexed: 12/24/2022]
Abstract
PURPOSE To assess the amide proton transfer-weighted (APTw) MRI features of isocitrate dehydrogenase (IDH)-wildtype and IDH-mutant grade II gliomas and to test the hypothesis that the APTw signal is a surrogate imaging marker for identifying IDH mutation status preoperatively. METHODS Twenty-seven patients with pathologically confirmed low-grade glioma, who were previously scanned at 3T, were retrospectively analyzed. The Mann-Whitney test was used to evaluate relationships between APTw intensities for IDH-mutant and IDH-wildtype groups, and receiver operator characteristic (ROC) analysis was used to assess the diagnostic performance of APTw. RESULTS Based on histopathology and molecular analysis, seven cases were diagnosed as IDH-wildtype grade II gliomas and 20 cases as IDH-mutant grade II gliomas. The maximum and minimum APTw values, based on multiple regions of interest, as well as the whole-tumor histogram-based mean and 50th percentile APTw values, were significantly higher in the IDH-wildtype gliomas than in the IDH-mutant groups. This corresponded to the areas under the ROC curves of 0.89, 0.76, 0.75, and 0.75, respectively, for the prediction of the IDH mutation status. CONCLUSION IDH-wildtype lesions typically were associated with relatively high APTw signal intensities as compared with IDH-mutant lesions. The APTw signal could be a valuable imaging biomarker by which to identify IDH1 mutation status in grade II gliomas. Magn Reson Med 78:1100-1109, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Shanshan Jiang
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China.,Department of Radiology, Futian Traditional Chinese Medicine Hospital, Shenzhen, Guangdong, China
| | - Tianyu Zou
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Charles G Eberhart
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland, USA
| | | | - Hye-Young Heo
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yi Zhang
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yu Wang
- Department of Pathology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Xianlong Wang
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Hao Yu
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Yongxing Du
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Peter C M van Zijl
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Zhibo Wen
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Jinyuan Zhou
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
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Varma G, Girard OM, Prevost VH, Grant AK, Duhamel G, Alsop DC. In vivo measurement of a new source of contrast, the dipolar relaxation time, T 1D , using a modified inhomogeneous magnetization transfer (ihMT) sequence. Magn Reson Med 2016; 78:1362-1372. [PMID: 27859618 DOI: 10.1002/mrm.26523] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/27/2016] [Accepted: 10/01/2016] [Indexed: 02/04/2023]
Abstract
PURPOSE This paper describes a technique that can be used in vivo to measure the dipolar relaxation time, T1D , of macromolecular protons contributing to magnetization transfer (MT) in tissues and to produce quantitative T1D maps. THEORY AND METHODS The technique builds upon the inhomogeneous MT (ihMT) technique that is particularly sensitive to tissue components with long T1D . A standard ihMT experiment was altered to introduce a variable time for switching between positive and negative offset frequencies for RF saturation. A model for the dependence of ihMT was developed and used to fit data acquired in vivo. RESULTS Application of the method to images from brains of healthy volunteers produced values of T1D = (5.9 ± 1.2) ms in gray matter and T1D = (6.2 ± 0.4) ms in white matter regions and provided maps of the T1D parameter. CONCLUSION The model and experiments described provide access to a new relaxation characteristic of tissue with potentially unique diagnostic information. Magn Reson Med 78:1362-1372, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Gopal Varma
- Department of Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Olivier M Girard
- Aix Marseille Université, CNRS, CRMBM-CEMEREM, UMR 7339, Marseille, France
| | - Valentin H Prevost
- Aix Marseille Université, CNRS, CRMBM-CEMEREM, UMR 7339, Marseille, France
| | - Aaron K Grant
- Department of Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Guillaume Duhamel
- Aix Marseille Université, CNRS, CRMBM-CEMEREM, UMR 7339, Marseille, France
| | - David C Alsop
- Department of Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
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Zhang H, Kang H, Zhao X, Jiang S, Zhang Y, Zhou J, Peng Y. Amide Proton Transfer (APT) MR imaging and Magnetization Transfer (MT) MR imaging of pediatric brain development. Eur Radiol 2016; 26:3368-76. [PMID: 26762941 PMCID: PMC5747245 DOI: 10.1007/s00330-015-4188-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 12/03/2015] [Accepted: 12/21/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVES To quantify the brain maturation process during childhood using combined amide proton transfer (APT) and conventional magnetization transfer (MT) imaging at 3 Tesla. METHODS Eighty-two neurodevelopmentally normal children (44 males and 38 females; age range, 2-190 months) were imaged using an APT/MT imaging protocol with multiple saturation frequency offsets. The APT-weighted (APTW) and MT ratio (MTR) signals were quantitatively analyzed in multiple brain areas. Age-related changes in MTR and APTW were evaluated with a non-linear regression analysis. RESULTS The APTW signals followed a decreasing exponential curve with age in all brain regions measured (R(2) = 0.7-0.8 for the corpus callosum, frontal and occipital white matter, and centrum semiovale). The most significant changes appeared within the first year. At maturation, larger decreases in APTW and lower APTW values were found in the white matter. On the contrary, the MTR signals followed an increasing exponential curve with age in the same brain regions measured, with the most significant changes appearing within the initial 2 years. There was an inverse correlation between the MTR and APTW signal intensities during brain maturation. CONCLUSIONS Together with MT imaging, protein-based APT imaging can provide additional information in assessing brain myelination in the paediatric population. KEY POINTS • APTW signals followed a decreasing exponential curve with age. • The most significant APTW changes appeared within the first year • At maturation, larger APTW decreases and lower APTW appeared in white matter • MTR signals followed an increasing exponential curve with age.
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Affiliation(s)
- Hong Zhang
- Imaging Center, Department of Radiology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Huiying Kang
- Imaging Center, Department of Radiology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | | | - Shanshan Jiang
- Division of MR Research, Department of Radiology, Johns Hopkins University, 600 N. Wolfe Street, Park 336, Baltimore, MD, 21287, USA
| | - Yi Zhang
- Division of MR Research, Department of Radiology, Johns Hopkins University, 600 N. Wolfe Street, Park 336, Baltimore, MD, 21287, USA
| | - Jinyuan Zhou
- Division of MR Research, Department of Radiology, Johns Hopkins University, 600 N. Wolfe Street, Park 336, Baltimore, MD, 21287, USA.
| | - Yun Peng
- Imaging Center, Department of Radiology, Beijing Children's Hospital, Capital Medical University, Beijing, China.
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Heo HY, Lee DH, Zhang Y, Zhao X, Jiang S, Chen M, Zhou J. Insight into the quantitative metrics of chemical exchange saturation transfer (CEST) imaging. Magn Reson Med 2016; 77:1853-1865. [PMID: 27170222 DOI: 10.1002/mrm.26264] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/01/2016] [Accepted: 04/14/2016] [Indexed: 12/25/2022]
Abstract
PURPOSE To evaluate the reliability of four CEST imaging metrics for brain tumors, at varied saturation power levels and magnetic field strengths (3-9.4 Tesla (T)). METHODS A five-pool proton exchange model (free water, semisolid, amide, amine, and NOE-related protons) was used for the simulations. For the in vivo study, eight glioma-bearing rats were scanned at 4.7 T. The CEST ratio (CESTR), CESTR normalized with the reference value (CESTRnr ), inverse Z-spectrum-based (MTRRex ), and apparent exchange-related relaxation (AREX) were compared. RESULTS The simulated CEST signal intensities using MTRRex and AREX were substantially increased at relatively high radiofrequency (RF) saturation powers at 3 T and 4.7 T, whereas CESTR and CESTRnr metrics remained relatively stable. There were tremendously high MTRRex and AREX signals around the water frequency at all field strengths because of the small denominators. In the rat tumor study at 4.7 T, both CESTR and CESTRnr showed clear contrasts in the tumor with respect to the normal tissue across all saturation power levels (0.5-3 μT), whereas the AREX showed negligible to negative insignificant contrasts. CONCLUSIONS CEST metrics must be carefully selected based on the different experimental settings. CESTR and CESTRnr are more reliable at 3 T (a clinical field strength) and 4.7 T. Magn Reson Med 77:1853-1865, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Hye-Young Heo
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Dong-Hoon Lee
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yi Zhang
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Xuna Zhao
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Shanshan Jiang
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Min Chen
- Department of Radiology, Beijing Hospital, Beijing, China
| | - Jinyuan Zhou
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
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Ma B, Blakeley JO, Hong X, Zhang H, Jiang S, Blair L, Zhang Y, Heo HY, Zhang M, van Zijl PCM, Zhou J. Applying amide proton transfer-weighted MRI to distinguish pseudoprogression from true progression in malignant gliomas. J Magn Reson Imaging 2016; 44:456-62. [PMID: 26788865 DOI: 10.1002/jmri.25159] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 01/04/2016] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To assess amide proton transfer-weighted (APTW) imaging features in patients with malignant gliomas after chemoradiation and the diagnostic performance of APT imaging for distinguishing true progression from pseudoprogression. MATERIALS AND METHODS After approval by the Institutional Review Board, 32 patients with clinically suspected tumor progression in the first 3 months after chemoradiation were enrolled and scanned at 3T. Longitudinal routine magnetic resonance imaging (MRI) changes and medical records were assessed to confirm true progression versus pseudoprogression. True progression was defined as lesions progressing on serial imaging over 6 months, and pseudoprogression was defined as lesions stabilizing or regressing without intervention. The APTWmean and APTWmax signals were obtained from three to five regions of interests for each patient and compared between the true progression and pseudoprogression groups. The diagnostic performance was assessed with receiver operating characteristic curve analysis. RESULTS The true progression was associated with APTW hyperintensity (APTWmean = 2.75% ± 0.42%), while pseudoprogression was associated with APTW isointensity to mild hyperintensity (APTWmean = 1.56% ± 0.42%). The APTW signal intensities were significantly higher in the true progression group (n = 20) than in the pseudoprogression group (P < 0.001; n = 12). The cutoff APTWmean and APTWmax intensity values to distinguish between true progression and pseudoprogression were 2.42% (with a sensitivity of 85.0% and a specificity of 100%) and 2.54% (with a sensitivity of 95.0% and a specificity of 91.7%), respectively. CONCLUSION The APTW-MRI signal is a valuable imaging biomarker for distinguishing pseudoprogression from true progression in glioma patients. J. Magn. Reson. Imaging 2016;44:456-462.
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Affiliation(s)
- Bo Ma
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Oncology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China.,Department of Radiology, Henan Provincial People's Hospital, Zhengzhou, Henan, PR China
| | - Jaishri O Blakeley
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Xiaohua Hong
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Hongyan Zhang
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Shanshan Jiang
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Lindsay Blair
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yi Zhang
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Hye-Young Heo
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Mingzhi Zhang
- Department of Oncology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China
| | - Peter C M van Zijl
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Jinyuan Zhou
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
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13
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Delli Castelli D, Ferrauto G, Di Gregorio E, Terreno E, Aime S. Sensitive MRI detection of internalized T1 contrast agents using magnetization transfer contrast. NMR IN BIOMEDICINE 2015; 28:1663-1670. [PMID: 26474109 DOI: 10.1002/nbm.3423] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 09/03/2015] [Accepted: 09/06/2015] [Indexed: 06/05/2023]
Abstract
This work addresses the possibility of using Magnetization Transfer Contrast (MTC) for an improved MRI detection of T1 relaxation agents. The need to improve the detection threshold of MRI agents is particularly stringent when the contrast agents failed to accumulate to the proper extent in targeting procedures. The herein reported approach is based on the T1 dependence of MT contrast. It has been assessed that MT contrast can allow the detection of a Gd-containing agent at a lower detection threshold than the one accessible by acquiring T1W images. Measurements have been carried out either in TS/A cells or in vivo in a syngeneic murine breast cancer model. The reported data showed that in cellular experiments the MTC method displays a better sensitivity with respect to the common T1W experiments. In particular, the reached detection threshold allowed the visualization of samples containing only 2% of Gd-labeled cells diluted in unlabeled cells. In vivo experiments displayed a more diversified scheme. In particular, the tumor region showed two distinct behaviors accordingly with the localization of the imaging probe. The probe located in the tumor core could be detected to the same extent either by T1w or MTC contrast. Conversely, the agent located in the tumor rim was detected with a larger sensitivity by the MTC method herein described.
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Affiliation(s)
- Daniela Delli Castelli
- Molecular & Preclinical Imaging Centers, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Giuseppe Ferrauto
- Molecular & Preclinical Imaging Centers, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Enza Di Gregorio
- Molecular & Preclinical Imaging Centers, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Enzo Terreno
- Molecular & Preclinical Imaging Centers, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
- IBB-CNR- UOS, University of Torino, Torino, Italy
| | - Silvio Aime
- Molecular & Preclinical Imaging Centers, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
- IBB-CNR- UOS, University of Torino, Torino, Italy
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14
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Enzinger C, Barkhof F, Ciccarelli O, Filippi M, Kappos L, Rocca MA, Ropele S, Rovira À, Schneider T, de Stefano N, Vrenken H, Wheeler-Kingshott C, Wuerfel J, Fazekas F. Nonconventional MRI and microstructural cerebral changes in multiple sclerosis. Nat Rev Neurol 2015; 11:676-86. [PMID: 26526531 DOI: 10.1038/nrneurol.2015.194] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
MRI has become the most important paraclinical tool for diagnosing and monitoring patients with multiple sclerosis (MS). However, conventional MRI sequences are largely nonspecific in the pathology they reveal, and only provide a limited view of the complex morphological changes associated with MS. Nonconventional MRI techniques, such as magnetization transfer imaging (MTI), diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) promise to complement existing techniques by revealing more-specific information on microstructural tissue changes. Past years have witnessed dramatic advances in the acquisition and analysis of such imaging data, and numerous studies have used these tools to probe tissue alterations associated with MS. Other MRI-based techniques-such as myelin-water imaging, (23)Na imaging, magnetic resonance elastography and magnetic resonance perfusion imaging-might also shed new light on disease-associated changes. This Review summarizes the rapid technical progress in the use of MRI in patients with MS, with a focus on nonconventional structural MRI. We critically discuss the present utility of nonconventional MRI in MS, and provide an outlook on future applications, including clinical practice. This information should allow appropriate selection of advanced MRI techniques, and facilitate their use in future studies of this disease.
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Affiliation(s)
- Christian Enzinger
- Division of Neuroradiology, Medical University of Graz, Auenbruggerplatz 22, 8036 Graz, Austria.,Department of Neurology, Medical University of Graz, Auenbruggerplatz 22, 8036 Graz, Austria
| | - Frederik Barkhof
- VU University MS Center Amsterdam, Department of Radiology and Nuclear Medicine and Department of Physics &Medical Technology, VU University Medical Center, Netherlands
| | - Olga Ciccarelli
- NMR Research Unit, Queen Square MS Centre, University College London Institute of Neurology, UK
| | - Massimo Filippi
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Italy
| | - Ludwig Kappos
- Department of Neurology, University of Basel, Switzerland
| | - Maria A Rocca
- Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Italy
| | - Stefan Ropele
- Department of Neurology, Medical University of Graz, Auenbruggerplatz 22, 8036 Graz, Austria
| | - Àlex Rovira
- Magnetic Resonance Unit, Cemcat, Hospital Vall d'Hebron, Autonomous University of Barcelona, Spain
| | - Torben Schneider
- NMR Research Unit, Queen Square MS Centre, University College London Institute of Neurology, UK
| | - Nicola de Stefano
- Department of Neurological and Behavioural Sciences, University of Siena, Italy
| | - Hugo Vrenken
- VU University MS Center Amsterdam, Department of Radiology and Nuclear Medicine and Department of Physics &Medical Technology, VU University Medical Center, Netherlands
| | | | - Jens Wuerfel
- Medical Image Analysis Center, University Hospital Basel, Switzerland
| | - Franz Fazekas
- Department of Neurology, Medical University of Graz, Auenbruggerplatz 22, 8036 Graz, Austria
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15
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Varma G, Girard OM, Prevost VH, Grant AK, Duhamel G, Alsop DC. Interpretation of magnetization transfer from inhomogeneously broadened lines (ihMT) in tissues as a dipolar order effect within motion restricted molecules. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 260:67-76. [PMID: 26408956 DOI: 10.1016/j.jmr.2015.08.024] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 08/11/2015] [Accepted: 08/30/2015] [Indexed: 05/24/2023]
Abstract
Comparison of off-resonance saturation with single and dual frequency irradiation indicates a contribution of inhomogeneously broadened lines to magnetization transfer in tissues. This inhomogeneous magnetization transfer (ihMT) phenomenon can be exploited to produce images that highlight tissues containing myelin, in vivo. Here, a model for ihMT is described that includes dipolar order effects from magnetization associated with motion-restricted macromolecules. In this model, equal irradiation at positive and negative frequency offsets eliminates dipolar order and achieves greater saturation than irradiation at a single offset frequency using the same power. Fitting of mouse and human volunteer brain data at different irradiation powers and offset frequencies was performed to assess the relevance of the model and approximate tissue parameters. A key parameter in determining ihMT signal was found to be the relaxation time T1D associated with the dipolar order reservoir and the fraction f of the semi-solid, bound magnetization that possessed a nonzero T1D. Indeed, better fits of myelinated tissue were achieved when assuming f≠1. From such fits, estimated T1Ds of mice in the white matter, (34±14) ms, were much longer than in muscle, T1D=(1±1) ms and the average f from white matter volunteer data was 2.2 times greater than that in grey matter. The combination of f and longer T1Ds was primarily responsible for the much higher ihMT in myelinated tissues, and provided explanation for the species variation. This dipolar order ihMT model should help guide future research, pulse sequence optimization, and clinical applications.
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Affiliation(s)
- G Varma
- Department of Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
| | - O M Girard
- Aix Marseille Université, CRMBM-CEMEREM UMR 7339, CNRS - AMU, Marseille, France
| | - V H Prevost
- Aix Marseille Université, CRMBM-CEMEREM UMR 7339, CNRS - AMU, Marseille, France
| | - A K Grant
- Department of Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - G Duhamel
- Aix Marseille Université, CRMBM-CEMEREM UMR 7339, CNRS - AMU, Marseille, France
| | - D C Alsop
- Department of Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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16
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Lee JS, Xia D, Jerschow A, Regatte RR. In vitro study of endogenous CEST agents at 3 T and 7 T. CONTRAST MEDIA & MOLECULAR IMAGING 2015; 11:4-14. [PMID: 26153196 DOI: 10.1002/cmmi.1652] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/18/2015] [Accepted: 05/20/2015] [Indexed: 12/16/2022]
Abstract
Chemical exchange saturation transfer (CEST) has been an intensive research area in MRI, providing contrast mechanisms for the amplified detection and monitoring of biomarkers and physiologically active molecules. In biological tissues and organs, many endogenous CEST agents coexist, and their CEST effects may overlap. The interpretation of such overlapped CEST effects can be addressed when the individual CEST effects originating from various metabolites are characterized. In this work, we present the in vitro measurements of the CEST effects from endogenous CEST agents that are commonly found in biological tissues and organs, at the external magnetic fields of 3 T and 7 T and under various pH conditions. Together with the proton NMR spectra measured at 11.7 T, these CEST effects have been evaluated in consideration of the chemical exchange rates, chemical shifts, and acidities of the labile protons. Amine protons of small metabolites might not be visible at 3 T, but some of them can be probed at 7 T, wherein their CEST effects may overlap with those from coexisting amide and hydroxyl protons.
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Affiliation(s)
- Jae-Seung Lee
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.,Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.,Department of Chemistry, New York University, New York, NY, USA
| | - Ding Xia
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.,Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Alexej Jerschow
- Department of Chemistry, New York University, New York, NY, USA
| | - Ravinder R Regatte
- Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, USA.,Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
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17
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Friedman JI, Xia D, Regatte RR, Jerschow A. Transfer Rate Edited experiment for the selective detection of Chemical Exchange via Saturation Transfer (TRE-CEST). JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 256:43-51. [PMID: 25996515 PMCID: PMC4466164 DOI: 10.1016/j.jmr.2015.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 03/25/2015] [Accepted: 04/20/2015] [Indexed: 05/08/2023]
Abstract
Chemical Exchange Saturation Transfer (CEST) magnetic resonance experiments have become valuable tools in magnetic resonance for the detection of low concentration solutes with far greater sensitivity than direct detection methods. Accurate measures of rates of chemical exchange provided by CEST are of particular interest to biomedical imaging communities where variations in chemical exchange can be related to subtle variations in biomarker concentration, temperature and pH within tissues using MRI. Despite their name, however, traditional CEST methods are not truly selective for chemical exchange and instead detect all forms of magnetization transfer including through-space NOE. This ambiguity crowds CEST spectra and greatly complicates subsequent data analysis. We have developed a Transfer Rate Edited CEST experiment (TRE-CEST) that uses two different types of solute labeling in order to selectively amplify signals of rapidly exchanging proton species while simultaneously suppressing 'slower' NOE-dominated magnetization transfer processes. This approach is demonstrated in the context of both NMR and MRI, where it is used to detect the labile amide protons of proteins undergoing chemical exchange (at rates⩾30s(-1)) while simultaneously eliminating signals originating from slower (∼5s(-1)) NOE-mediated magnetization transfer processes. TRE-CEST greatly expands the utility of CEST experiments in complex systems, and in-vivo, in particular, where it is expected to improve the quantification of chemical exchange and magnetization transfer rates while enabling new forms of imaging contrast.
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Affiliation(s)
- Joshua I Friedman
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Ding Xia
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, USA
| | - Ravinder R Regatte
- Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, USA
| | - Alexej Jerschow
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA
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18
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Goerke S, Zaiss M, Kunz P, Klika KD, Windschuh JD, Mogk A, Bukau B, Ladd ME, Bachert P. Signature of protein unfolding in chemical exchange saturation transfer imaging. NMR IN BIOMEDICINE 2015; 28:906-13. [PMID: 26010522 DOI: 10.1002/nbm.3317] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/11/2015] [Accepted: 04/07/2015] [Indexed: 05/24/2023]
Abstract
Chemical exchange saturation transfer (CEST) allows the detection of metabolites of low concentration in tissue with nearly the sensitivity of MRI with water protons. With this spectroscopic imaging approach, several tissue-specific CEST effects have been observed in vivo. Some of these originate from exchanging sites of proteins, such as backbone amide protons, or from aliphatic protons within the hydrophobic protein core. In this work, we employed CEST experiments to detect global protein unfolding. Spectral evaluation revealed exchange- and NOE-mediated CEST effects that varied in a highly characteristic manner with protein unfolding tracked by fluorescence spectroscopy. We suggest the use of this comprehensive spectral signature for the detection of protein unfolding by CEST, as it relies on several spectral hallmarks. As proof of principle, we demonstrate that the presented signature is readily detectable using a whole-body MR tomograph (B0 = 7 T), not only in denatured aqueous protein solutions, but also in heat-shocked yeast cells. A CEST imaging contrast with the potential to detect global protein unfolding would be of particular interest regarding protein unfolding as a marker for stress, ageing, and disease.
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Affiliation(s)
- Steffen Goerke
- Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum [German Cancer Research Center] (DKFZ), Heidelberg, Baden-Württemberg, Germany
| | - Moritz Zaiss
- Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum [German Cancer Research Center] (DKFZ), Heidelberg, Baden-Württemberg, Germany
| | - Patrick Kunz
- Division of Functional Genome Analysis, Deutsches Krebsforschungszentrum [German Cancer Research Center] (DKFZ), Heidelberg, Baden-Württemberg, Germany
| | - Karel D Klika
- Molecular Structure Analysis, Deutsches Krebsforschungszentrum [German Cancer Research Center] (DKFZ), Heidelberg, Baden-Württemberg, Germany
| | - Johannes D Windschuh
- Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum [German Cancer Research Center] (DKFZ), Heidelberg, Baden-Württemberg, Germany
| | - Axel Mogk
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Allianz, Heidelberg, Baden-Württemberg, Germany
- Deutsches Krebsforschungszentrum [German Cancer Research Center] (DKFZ), Heidelberg, Baden-Württemberg, Germany
| | - Bernd Bukau
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Allianz, Heidelberg, Baden-Württemberg, Germany
- Deutsches Krebsforschungszentrum [German Cancer Research Center] (DKFZ), Heidelberg, Baden-Württemberg, Germany
| | - Mark E Ladd
- Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum [German Cancer Research Center] (DKFZ), Heidelberg, Baden-Württemberg, Germany
| | - Peter Bachert
- Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum [German Cancer Research Center] (DKFZ), Heidelberg, Baden-Württemberg, Germany
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19
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Heo HY, Zhang Y, Jiang S, Lee DH, Zhou J. Quantitative assessment of amide proton transfer (APT) and nuclear overhauser enhancement (NOE) imaging with extrapolated semisolid magnetization transfer reference (EMR) signals: II. Comparison of three EMR models and application to human brain glioma at 3 Tesla. Magn Reson Med 2015; 75:1630-9. [PMID: 26033553 DOI: 10.1002/mrm.25795] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 04/08/2015] [Accepted: 05/01/2015] [Indexed: 12/27/2022]
Abstract
PURPOSE To evaluate the use of three extrapolated semisolid magnetization transfer reference (EMR) methods to quantify amide proton transfer (APT) and nuclear Overhauser enhancement (NOE) signals in human glioma. METHODS Eleven patients with high-grade glioma were scanned at 3 Tesla. aEMR(2) (asymmetric magnetization-transfer or MT model to fit two-sided, wide-offset data), sEMR(2) (symmetric MT model to fit two-sided, wide-offset data), and sEMR(1) (symmetric MT model to fit one-sided, wide-offset data) were assessed. ZEMR and experimental data at 3.5 ppm and -3.5 ppm were subtracted to calculate the APT and NOE signals (APT(#) and NOE(#)), respectively. RESULTS The aEMR(2) and sEMR(1) models provided quite similar APT(#) signals, while the sEMR(2) provided somewhat lower APT(#) signals. The aEMR(2) had an erroneous NOE(#) quantification. Calculated APT(#) signal intensities of glioma (∼4%), much larger than the values reported previously, were significantly higher than those of edema and normal tissue. Compared with normal tissue, gadolinium-enhancing tumor cores were consistently hyperintense on the APT(#) maps and slightly hypointense on the NOE(#) maps. CONCLUSION The sEMR(1) model is the best choice for accurately quantifying APT and NOE signals. The APT-weighted hyperintensity in the tumor was dominated by the APT effect, and the MT asymmetry at 3.5 ppm is a reliable and valid metric for APT imaging of gliomas at 3T.
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Affiliation(s)
- Hye-Young Heo
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yi Zhang
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Shanshan Jiang
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Dong-Hoon Lee
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jinyuan Zhou
- Divison of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
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20
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Wang M, Hong X, Chang CF, Li Q, Ma B, Zhang H, Xiang S, Heo HY, Zhang Y, Lee DH, Jiang S, Leigh R, Koehler RC, van Zijl PCM, Wang J, Zhou J. Simultaneous detection and separation of hyperacute intracerebral hemorrhage and cerebral ischemia using amide proton transfer MRI. Magn Reson Med 2015; 74:42-50. [PMID: 25879165 DOI: 10.1002/mrm.25690] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 02/13/2015] [Accepted: 02/17/2015] [Indexed: 12/15/2022]
Abstract
PURPOSE To explore the capability of amide proton transfer (APT) imaging in the detection of hemorrhagic and ischemic strokes using preclinical rat models. METHODS The rat intracerebral hemorrhage (ICH) model (n = 10) was induced by injecting bacterial collagenase VII-S into the caudate nucleus, and the permanent ischemic stroke model (n = 10) was induced by using a 4-0 nylon suture to occlude the origin of the middle cerebral artery. APT-weighted (APTw) MRI was acquired on a 4.7T animal imager and quantified using the magnetization transfer-ratio asymmetry at 3.5 ppm from water. RESULTS There was a consistently high APTw MRI signal in hyperacute ICH during the initial 12 h after injection of collagenase compared with the contralateral brain tissue. When hemorrhagic and ischemic stroke were compared, hyperacute ICH and cerebral ischemia demonstrated opposite APTw MRI contrasts-namely, hyperintense versus hypointense compared with contralateral brain tissue, respectively. There was a stark contrast in APTw signal intensity between these two lesions. CONCLUSION APT-MRI could accurately detect hyperacute ICH and distinctly differentiate hyperacute ICH from cerebral ischemia, thus opening up the possibility of introducing to the clinic a single MRI scan for the simultaneous visualization and separation of hemorrhagic and ischemic strokes at the hyperacute stage. Magn Reson Med 74:42-50, 2015. © 2014 Wiley Periodicals, Inc.
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Affiliation(s)
- Meiyun Wang
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Xiaohua Hong
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Che-Feng Chang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Qiang Li
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Bo Ma
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hong Zhang
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Sinan Xiang
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hye-Young Heo
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Yi Zhang
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Dong-Hoon Lee
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Shanshan Jiang
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Richard Leigh
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Raymond C Koehler
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Peter C M van Zijl
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Jian Wang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jinyuan Zhou
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
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21
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Zaiss M, Windschuh J, Paech D, Meissner JE, Burth S, Schmitt B, Kickingereder P, Wiestler B, Wick W, Bendszus M, Schlemmer HP, Ladd ME, Bachert P, Radbruch A. Relaxation-compensated CEST-MRI of the human brain at 7T: Unbiased insight into NOE and amide signal changes in human glioblastoma. Neuroimage 2015; 112:180-188. [PMID: 25727379 DOI: 10.1016/j.neuroimage.2015.02.040] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 02/05/2015] [Accepted: 02/18/2015] [Indexed: 11/30/2022] Open
Abstract
Endogenous chemical exchange saturation transfer (CEST) effects of protons resonating near to water protons are always diluted by competing effects such as direct water saturation and semi-solid magnetization transfer (MT). This leads to unwanted T2 and MT signal contributions that contaminate the observed CEST signal. Furthermore, all CEST effects appear to be scaled by the T1 relaxation time of the mediating water pool. As MT, T1 and T2 are also altered in tumor regions, a recently published correction algorithm yielding the apparent exchange-dependent relaxation AREX, is used to evaluate in vivo CEST effects. This study focuses on CEST effects of amides (3.5ppm) and Nuclear-Overhauser-mediated saturation transfer (NOE, -3.5ppm) that can be properly isolated at 7T. These were obtained in 10 glioblastoma patients, and this is the first comprehensive study where AREX is applied in human brain as well as in human glioblastoma. The correction of CEST effects alters the contrast significantly: after correction, the CEST effect of amides does not show significant contrast between contrast enhancing tumor regions and normal tissue, whereas NOE drops significantly in the tumor area. In addition, new features in the AREX contrasts are visible. This suggests that previous CEST approaches might not have shown pure CEST effects, but rather water relaxation shine-through effects. Our insights help to improve understanding of the CEST effect changes in tumors and correlations on a cellular and molecular level.
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Affiliation(s)
- Moritz Zaiss
- Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany.
| | - Johannes Windschuh
- Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Daniel Paech
- Department of Neuroradiology, University of Heidelberg Medical Center, Heidelberg, Germany; Neurooncologic Imaging, Department of Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Jan-Eric Meissner
- Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany; Neurooncologic Imaging, Department of Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Sina Burth
- Department of Neuroradiology, University of Heidelberg Medical Center, Heidelberg, Germany; Neurooncologic Imaging, Department of Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | | | - Philip Kickingereder
- Department of Neuroradiology, University of Heidelberg Medical Center, Heidelberg, Germany
| | - Benedikt Wiestler
- University of Heidelberg Neurology Clinic, Heidelberg, Germany; Clinical Cooperation Unit Neuro-oncology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Wolfgang Wick
- University of Heidelberg Neurology Clinic, Heidelberg, Germany; Clinical Cooperation Unit Neuro-oncology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Martin Bendszus
- Department of Neuroradiology, University of Heidelberg Medical Center, Heidelberg, Germany
| | - Heinz-Peter Schlemmer
- Department of Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Mark E Ladd
- Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Peter Bachert
- Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Alexander Radbruch
- Department of Neuroradiology, University of Heidelberg Medical Center, Heidelberg, Germany; Neurooncologic Imaging, Department of Radiology, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
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22
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Grosse U, Syha R, Hein T, Gatidis S, Grözinger G, Schabel C, Martirosian P, Schick F, Springer F. Diagnostic value of T1and T2* relaxation times and off-resonance saturation effects in the evaluation of achilles tendinopathy by MRI at 3T. J Magn Reson Imaging 2014; 41:964-73. [DOI: 10.1002/jmri.24657] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Revised: 04/10/2014] [Accepted: 04/13/2014] [Indexed: 12/21/2022] Open
Affiliation(s)
- Ulrich Grosse
- Department of Diagnostic and Interventional Radiology; University Hospital Tuebingen; Tuebingen Germany
- Section on Experimental Radiology; University Hospital Tuebingen; Tuebingen Germany
| | - Roland Syha
- Department of Diagnostic and Interventional Radiology; University Hospital Tuebingen; Tuebingen Germany
- Section on Experimental Radiology; University Hospital Tuebingen; Tuebingen Germany
| | - Tobias Hein
- Department of Sports Medicine; University Hospital Tuebingen; Tuebingen Germany
| | - Sergios Gatidis
- Department of Diagnostic and Interventional Radiology; University Hospital Tuebingen; Tuebingen Germany
- Section on Experimental Radiology; University Hospital Tuebingen; Tuebingen Germany
| | - Gerd Grözinger
- Department of Diagnostic and Interventional Radiology; University Hospital Tuebingen; Tuebingen Germany
- Section on Experimental Radiology; University Hospital Tuebingen; Tuebingen Germany
| | - Christoph Schabel
- Department of Diagnostic and Interventional Radiology; University Hospital Tuebingen; Tuebingen Germany
- Section on Experimental Radiology; University Hospital Tuebingen; Tuebingen Germany
| | - Petros Martirosian
- Section on Experimental Radiology; University Hospital Tuebingen; Tuebingen Germany
| | - Fritz Schick
- Section on Experimental Radiology; University Hospital Tuebingen; Tuebingen Germany
| | - Fabian Springer
- Department of Diagnostic and Interventional Radiology; University Hospital Tuebingen; Tuebingen Germany
- Section on Experimental Radiology; University Hospital Tuebingen; Tuebingen Germany
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