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Bloch modelling enables robust T2 mapping using retrospective proton density and T2-weighted images from different vendors and sites. Neuroimage 2021; 237:118116. [PMID: 33940150 DOI: 10.1016/j.neuroimage.2021.118116] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/14/2021] [Accepted: 04/15/2021] [Indexed: 10/21/2022] Open
Abstract
T2 quantification is commonly attempted by applying an exponential fit to proton density (PD) and transverse relaxation (T2)-weighted fast spin echo (FSE) images. However, inter-site studies have noted systematic differences between vendors in T2 maps computed via standard exponential fitting due to imperfect slice refocusing, different refocusing angles and transmit field (B1+) inhomogeneity. We examine T2 mapping at 3T across 13 sites and two vendors in healthy volunteers from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database using both a standard exponential and a Bloch modelling approach. The standard exponential approach resulted in highly variable T2 values across different sites and vendors. The two-echo fitting method based on Bloch equation modelling of the pulse sequence with prior knowledge of the nominal refocusing angles, slice profiles, and estimated B1+ maps yielded similar T2 values across sites and vendors by accounting for the effects of indirect and stimulated echoes. By modelling the actual refocusing angles used, T2 quantification from PD and T2-weighted images can be applied in studies across multiple sites and vendors.
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Emmerich J, Flassbeck S, Schmidt S, Bachert P, Ladd ME, Straub S. Rapid and accurate dictionary-based T 2 mapping from multi-echo turbo spin echo data at 7 Tesla. J Magn Reson Imaging 2018; 49:1253-1262. [PMID: 30328209 DOI: 10.1002/jmri.26516] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 08/03/2018] [Accepted: 09/04/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Using lower refocusing flip angles in multi-echo turbo spin echo (ME-TSE) sequences at ultra-high magnetic field leads to non-monoexponential signal decay and overestimation of T2 values due to stimulated and secondary echoes. PURPOSE To investigate the feasibility of a fast and accurate reconstruction of quantitative T2 values using an ME-TSE sequence with reduced refocusing flip angles at 7 Tesla, a dictionary-based reconstruction method was developed and is presented in this work. STUDY TYPE Prospective. SUBJECTS Phantom measurements with relaxation phantom, four healthy volunteers. FIELD STRENGTH/SEQUENCE 7 Tesla MRI, multi-echo turbo spin echo (ME-TSE), spin echo (SE), and B1 mapping. ASSESSMENT Based on Bloch simulations and the extended phase graph model, signal decay curves were calculated to account for nonrectangular slice profile, B1 inhomogeneity, and reduced refocusing flip angles and stored in a dictionary. Data obtained with an ME-TSE sequence at 7 Tesla were matched to this dictionary to obtain T2 values. To compare the proposed method to reference T2 values, a spin echo sequence with different echo times was used. STATISTICAL TESTS Welch's t-test was used to compare T2 values in phantom measurements. RESULTS T2 values obtained with the proposed ME-TSE method coincided with the T2 values from the spin echo experiment in phantom measurements (P = 0.89 for 120° flip angle, P = 0.75 for 180° flip angle). Only for very low B1 transmit fields, a slight overestimation of T2 values was observed. In vivo measurements showed lower T2 values in gray matter (55 ± 2 millisecond) and white matter (39 ± 5 millisecond) compared with literature values of 3 Tesla data. DATA CONCLUSIONS The proposed dictionary-based ME-TSE approach provided accurate T2 values in short measurement time at 7 Tesla with low specific absorption rate burden due to the reduction of refocusing flip angles. Therefore, it can provide new opportunities in clinical high-field MRI to further improve radiographic diagnosis by using quantitative imaging. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:1253-1262.
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Affiliation(s)
- Julian Emmerich
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Sebastian Flassbeck
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Simon Schmidt
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Peter Bachert
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Mark E Ladd
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany.,Faculty of Medicine, Heidelberg University, Heidelberg, Germany
| | - Sina Straub
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Mills AF, Sakai O, Anderson SW, Jara H. Principles of Quantitative MR Imaging with Illustrated Review of Applicable Modular Pulse Diagrams. Radiographics 2017; 37:2083-2105. [PMID: 28985137 DOI: 10.1148/rg.2017160099] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Continued improvements in diagnostic accuracy using magnetic resonance (MR) imaging will require development of methods for tissue analysis that complement traditional qualitative MR imaging studies. Quantitative MR imaging is based on measurement and interpretation of tissue-specific parameters independent of experimental design, compared with qualitative MR imaging, which relies on interpretation of tissue contrast that results from experimental pulse sequence parameters. Quantitative MR imaging represents a natural next step in the evolution of MR imaging practice, since quantitative MR imaging data can be acquired using currently available qualitative imaging pulse sequences without modifications to imaging equipment. The article presents a review of the basic physical concepts used in MR imaging and how quantitative MR imaging is distinct from qualitative MR imaging. Subsequently, the article reviews the hierarchical organization of major applicable pulse sequences used in this article, with the sequences organized into conventional, hybrid, and multispectral sequences capable of calculating the main tissue parameters of T1, T2, and proton density. While this new concept offers the potential for improved diagnostic accuracy and workflow, awareness of this extension to qualitative imaging is generally low. This article reviews the basic physical concepts in MR imaging, describes commonly measured tissue parameters in quantitative MR imaging, and presents the major available pulse sequences used for quantitative MR imaging, with a focus on the hierarchical organization of these sequences. ©RSNA, 2017.
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Affiliation(s)
- Andrew F Mills
- From the Department of Radiology (A.F.M., O.S., S.W.A., H.J.), Boston Medical Center, 820 Harrison Ave, FGH Building Third Floor, Boston, MA 02118; and the Department of Otolaryngology-Head and Neck Surgery and Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Mass (O.S.)
| | - Osamu Sakai
- From the Department of Radiology (A.F.M., O.S., S.W.A., H.J.), Boston Medical Center, 820 Harrison Ave, FGH Building Third Floor, Boston, MA 02118; and the Department of Otolaryngology-Head and Neck Surgery and Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Mass (O.S.)
| | - Stephan W Anderson
- From the Department of Radiology (A.F.M., O.S., S.W.A., H.J.), Boston Medical Center, 820 Harrison Ave, FGH Building Third Floor, Boston, MA 02118; and the Department of Otolaryngology-Head and Neck Surgery and Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Mass (O.S.)
| | - Hernan Jara
- From the Department of Radiology (A.F.M., O.S., S.W.A., H.J.), Boston Medical Center, 820 Harrison Ave, FGH Building Third Floor, Boston, MA 02118; and the Department of Otolaryngology-Head and Neck Surgery and Department of Radiation Oncology, Boston Medical Center, Boston University School of Medicine, Boston, Mass (O.S.)
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Gabr RE, Pednekar AS, Govindarajan KA, Sun X, Riascos RF, Ramírez MG, Hasan KM, Lincoln JA, Nelson F, Wolinsky JS, Narayana PA. Patient-specific 3D FLAIR for enhanced visualization of brain white matter lesions in multiple sclerosis. J Magn Reson Imaging 2016; 46:557-564. [PMID: 27869333 DOI: 10.1002/jmri.25557] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/01/2016] [Indexed: 12/22/2022] Open
Abstract
PURPOSE To improve the conspicuity of white matter lesions (WMLs) in multiple sclerosis (MS) using patient-specific optimization of single-slab 3D fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI). MATERIALS AND METHODS Sixteen MS patients were enrolled in a prospective 3.0T MRI study. FLAIR inversion time and echo time were automatically optimized for each patient during the same scan session based on measurements of the relative proton density and relaxation times of the brain tissues. The optimization criterion was to maximize the contrast between gray matter (GM) and white matter (WM), while suppressing cerebrospinal fluid. This criterion also helps increase the contrast between WMLs and WM. The performance of the patient-specific 3D FLAIR protocol relative to the fixed-parameter protocol was assessed both qualitatively and quantitatively. RESULTS Patient-specific optimization achieved a statistically significant 41% increase in the GM-WM contrast ratio (P < 0.05) and 32% increase in the WML-WM contrast ratio (P < 0.01) compared with fixed-parameter FLAIR. The increase in WML-WM contrast ratio correlated strongly with echo time (P < 10-11 ). Two experienced neuroradiologists indicated substantially higher lesion conspicuity on the patient-specific FLAIR images over conventional FLAIR in 3-4 cases (intrarater correlation coefficient ICC = 0.72). In no case was the image quality of patient-specific FLAIR considered inferior to conventional FLAIR by any of the raters (ICC = 0.32). CONCLUSION Changes in proton density and relaxation times render fixed-parameter FLAIR suboptimal in terms of lesion contrast. Patient-specific optimization of 3D FLAIR increases lesion conspicuity without scan time penalty, and has potential to enhance the detection of subtle and small lesions in MS. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:557-564.
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Affiliation(s)
- Refaat E Gabr
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | | | - Koushik A Govindarajan
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - Xiaojun Sun
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - Roy F Riascos
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - María G Ramírez
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - Khader M Hasan
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - John A Lincoln
- Department of Neurology, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - Flavia Nelson
- Department of Neurology, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - Jerry S Wolinsky
- Department of Neurology, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
| | - Ponnada A Narayana
- Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston (UTHealth), Houston, Texas, USA
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Abstract
Magnetic resonance imaging is a powerful, noninvasive imaging technique with exquisite sensitivity to soft tissue composition. Magnetic resonance imaging is primary tool for brain tumor diagnosis, evaluation of drug response assessment, and clinical monitoring of the patient during the course of their disease. The flexibility of magnetic resonance imaging pulse sequence design allows for a variety of image contrasts to be acquired, including information about magnetic resonance-specific tissue characteristics, molecular dynamics, microstructural organization, vascular composition, and biochemical status. The current review highlights recent advancements and novel approaches in MR characterization of brain tumors.
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Hunter DJ, Altman RD, Cicuttini F, Crema MD, Duryea J, Eckstein F, Guermazi A, Kijowski R, Link TM, Martel-Pelletier J, Miller CG, Mosher TJ, Ochoa-Albíztegui RE, Pelletier JP, Peterfy C, Raynauld JP, Roemer FW, Totterman SM, Gold GE. OARSI Clinical Trials Recommendations: Knee imaging in clinical trials in osteoarthritis. Osteoarthritis Cartilage 2015; 23:698-715. [PMID: 25952343 DOI: 10.1016/j.joca.2015.03.012] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 02/02/2023]
Abstract
Significant advances have occurred in our understanding of the pathogenesis of knee osteoarthritis (OA) and some recent trials have demonstrated the potential for modification of the disease course. The purpose of this expert opinion, consensus driven exercise is to provide detail on how one might use and apply knee imaging in knee OA trials. It includes information on acquisition methods/techniques (including guidance on positioning for radiography, sequence/protocol recommendations/hardware for magnetic resonance imaging (MRI)); commonly encountered problems (including positioning, hardware and coil failures, sequences artifacts); quality assurance (QA)/control procedures; measurement methods; measurement performance (reliability, responsiveness, validity); recommendations for trials; and research recommendations.
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Affiliation(s)
- D J Hunter
- Institute of Bone and Joint Research, Kolling Institute, University of Sydney, Sydney, NSW, Australia; Rheumatology Department, Royal North Shore Hospital, University of Sydney, Sydney, NSW, Australia.
| | - R D Altman
- Department of Medicine, Division of Rheumatology and Immunology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - F Cicuttini
- School of Public health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne 3004, Australia
| | - M D Crema
- Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, Hospital do Coração (HCor) and Teleimagem, São Paulo, SP, Brazil
| | - J Duryea
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Brazil
| | - F Eckstein
- Institute of Anatomy, Paracelsus Medical University Salzburg & Nuremberg, Salzburg, Austria; Chondrometrics GmbH, Ainring, Germany
| | - A Guermazi
- Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA
| | - R Kijowski
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - T M Link
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, USA
| | - J Martel-Pelletier
- Osteoarthritis Research Unit, University of Montreal Hospital Research Centre (CRCHUM), Montreal, Quebec, Canada
| | | | - T J Mosher
- Department of Radiology, Penn State University, Hershey, PA, USA; Department of Orthopaedic Surgery, Penn State University, Hershey, PA, USA
| | - R E Ochoa-Albíztegui
- Department of Radiology, The American British Cowdray Medical Center, Mexico City, Mexico
| | - J-P Pelletier
- Osteoarthritis Research Unit, University of Montreal Hospital Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - C Peterfy
- Spire Sciences, Inc., Boca Raton, Florida, USA
| | - J-P Raynauld
- Osteoarthritis Research Unit, University of Montreal Hospital Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - F W Roemer
- Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | | | - G E Gold
- Department of Radiology, Stanford University, Stanford, CA, USA; Department of Bioengineering, Stanford University, Stanford, CA, USA; Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA
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OARSI Clinical Trials Recommendations: Hip imaging in clinical trials in osteoarthritis. Osteoarthritis Cartilage 2015; 23:716-31. [PMID: 25952344 PMCID: PMC4430132 DOI: 10.1016/j.joca.2015.03.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 03/01/2015] [Accepted: 03/09/2015] [Indexed: 02/02/2023]
Abstract
Imaging of hip in osteoarthritis (OA) has seen considerable progress in the past decade, with the introduction of new techniques that may be more sensitive to structural disease changes. The purpose of this expert opinion, consensus driven recommendation is to provide detail on how to apply hip imaging in disease modifying clinical trials. It includes information on acquisition methods/techniques (including guidance on positioning for radiography, sequence/protocol recommendations/hardware for magnetic resonance imaging (MRI)); commonly encountered problems (including positioning, hardware and coil failures, artifacts associated with various MRI sequences); quality assurance/control procedures; measurement methods; measurement performance (reliability, responsiveness, and validity); recommendations for trials; and research recommendations.
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Ellingson BM, Lai A, Nguyen HN, Nghiemphu PL, Pope WB, Cloughesy TF. Quantification of Nonenhancing Tumor Burden in Gliomas Using Effective T2 Maps Derived from Dual-Echo Turbo Spin-Echo MRI. Clin Cancer Res 2015; 21:4373-83. [PMID: 25901082 DOI: 10.1158/1078-0432.ccr-14-2862] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 04/08/2015] [Indexed: 11/16/2022]
Abstract
PURPOSE Evaluation of nonenhancing tumor (NET) burden is an important yet challenging part of brain tumor response assessment. This study focuses on using dual-echo turbo spin-echo MRI as a means of quickly estimating tissue T2, which can be used to objectively define NET burden. EXPERIMENTAL DESIGN A series of experiments were performed to establish the use of T2 maps for defining NET burden. First, variation in T2 was determined using the American College of Radiology (ACR) water phantoms in 16 scanners evaluated over 3 years. Next, the sensitivity and specificity of T2 maps for delineating NET from other tissues were examined. Then, T2-defined NET was used to predict survival in separate subsets of patients with glioblastoma treated with radiotherapy, concurrent radiation, and chemotherapy, or bevacizumab at recurrence. RESULTS Variability in T2 in the ACR phantom was 3% to 5%. In training data, ROC analysis suggested that 125 ms < T2 < 250 ms could delineate NET with a sensitivity of >90% and specificity of >65%. Using this criterion, NET burden after completion of radiotherapy alone, or concurrent radiotherapy, and chemotherapy was shown to be predictive of survival (Cox, P < 0.05), and the change in NET volume before and after bevacizumab therapy in recurrent glioblastoma was also a predictive of survival (P < 0.05). CONCLUSIONS T2 maps using dual-echo data are feasible, stable, and can be used to objectively define NET burden for use in brain tumor characterization, prognosis, and response assessment. The use of effective T2 maps for defining NET burden should be validated in a randomized, clinical trial.
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Affiliation(s)
- Benjamin M Ellingson
- UCLA Neuro-Oncology Program, David Geffen School of Medicine, University of California, Los Angeles, California. Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California. Biomedical Physics Program, David Geffen School of Medicine, University of California, Los Angeles, California. Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, California. UCLA Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, California. Jonsson Comprehensive Cancer Center, University of California, Los Angeles, California.
| | - Albert Lai
- UCLA Neuro-Oncology Program, David Geffen School of Medicine, University of California, Los Angeles, California. Jonsson Comprehensive Cancer Center, University of California, Los Angeles, California. Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Huytram N Nguyen
- UCLA Neuro-Oncology Program, David Geffen School of Medicine, University of California, Los Angeles, California. Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Phioanh L Nghiemphu
- UCLA Neuro-Oncology Program, David Geffen School of Medicine, University of California, Los Angeles, California. Jonsson Comprehensive Cancer Center, University of California, Los Angeles, California. Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Whitney B Pope
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Timothy F Cloughesy
- UCLA Neuro-Oncology Program, David Geffen School of Medicine, University of California, Los Angeles, California. Jonsson Comprehensive Cancer Center, University of California, Los Angeles, California. Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, California
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Ben-Eliezer N, Sodickson DK, Shepherd T, Wiggins GC, Block KT. Accelerated and motion-robust in vivo T2 mapping from radially undersampled data using bloch-simulation-based iterative reconstruction. Magn Reson Med 2015; 75:1346-54. [PMID: 25891292 DOI: 10.1002/mrm.25558] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 11/04/2014] [Accepted: 11/11/2014] [Indexed: 11/09/2022]
Abstract
PURPOSE Development of a quantitative transverse relaxation time (T2)-mapping platform that operates at clinically feasible timescales by employing advanced image reconstruction of radially undersampled multi spin-echo (MSE) datasets. METHODS Data was acquired on phantom and in vivo at 3 Tesla using MSE protocols employing radial k-space sampling trajectories. In order to overcome the nontrivial spin evolution associated with MSE protocols, a numerical signal model was precalculated based on Bloch simulations of the actual pulse-sequence scheme used in the acquisition process. This signal model was subsequently incorporated into an iterative model-based image reconstruction process, producing T2 and proton-density maps. RESULTS T2 maps of phantom and in vivo brain were successfully constructed, closely matching values produced by a single spin-echo reference scan. High-resolution mapping was also performed for the spinal cord in vivo, differentiating the underlying gray/white matter morphology. CONCLUSION The presented MSE data-processing framework offers reliable mapping of T2 relaxation values in a ∼ 5-minute timescale, free of user- and scanner-dependent variations. The use of radial k-space sampling provides further advantages in the form of high immunity to irregular physiological motion, as well as enhanced spatial resolutions, owing to its inherent ability to perform alias-free limited field-of-view imaging.
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Affiliation(s)
- Noam Ben-Eliezer
- The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Daniel K Sodickson
- The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Timothy Shepherd
- The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Graham C Wiggins
- The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Kai Tobias Block
- The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
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