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Park J, Jang M, Heier L, Limperopoulos C, Zun Z. Rapid anatomical imaging of the neonatal brain using T 2 -prepared 3D balanced steady-state free precession. Magn Reson Med 2023; 89:1456-1468. [PMID: 36420869 PMCID: PMC10208121 DOI: 10.1002/mrm.29537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/18/2022] [Accepted: 11/03/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE To develop a new approach to 3D gradient echo-based anatomical imaging of the neonatal brain with a substantially shorter scan time than standard 3D fast spin echo (FSE) methods, while maintaining a high SNR. METHODS T2 -prepration was employed immediately prior to image acquisition of 3D balanced steady-state free precession (bSSFP) with a single trajectory of center-out k-space view ordering, which requires no magnetization recovery time between imaging segments during the scan. This approach was compared with 3D FSE, 2D single-shot FSE, and product 3D bSSFP imaging in numerical simulations, plus phantom and in vivo experiments. RESULTS T2 -prepared 3D bSSFP generated image contrast of gray matter, white matter, and CSF very similar to that of reference T2 -weighted imaging methods, without major image artifacts. Scan time of T2 -prepared 3D bSSFP was remarkably shorter compared to 3D FSE, whereas SNR was comparable to that of 3D FSE and higher than that of 2D single-shot FSE. Specific absorption rate of T2 -prepared 3D bSSFP remained within the safety limit. Determining an optimal imaging flip angle of T2 -prepared 3D bSSFP was critical to minimizing blurring of images. CONCLUSION T2 -prepared 3D bSSFP offers an alternative method for anatomical imaging of the neonatal brain with dramatically reduced scan time compared to standard 3D FSE and higher SNR than 2D single-shot FSE.
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Affiliation(s)
- Jinho Park
- Department of Cardiology, Yonsei University, Seoul, Korea
| | - MinJung Jang
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Korea
| | - Linda Heier
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Catherine Limperopoulos
- Developing Brain Institute, Division of Diagnostic Imaging and Radiology, Children’s National Hospital, Washington, DC, USA
- Division of Fetal and Transitional Medicine, Children’s National Hospital, Washington, DC, USA
- Department of Pediatrics, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA
- Department of Radiology, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA
| | - Zungho Zun
- Department of Radiology, Weill Cornell Medicine, New York, NY, USA
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Han F, Zhou Z, Du D, Gao Y, Rashid S, Cao M, Shaverdian N, Hegde JV, Steinberg M, Lee P, Raldow A, Low DA, Sheng K, Yang Y, Hu P. Respiratory motion-resolved, self-gated 4D-MRI using Rotating Cartesian K-space (ROCK): Initial clinical experience on an MRI-guided radiotherapy system. Radiother Oncol 2018; 127:467-473. [DOI: 10.1016/j.radonc.2018.04.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 03/23/2018] [Accepted: 04/24/2018] [Indexed: 11/17/2022]
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Gilani IA, Sepponen R. Quantitative rotating frame relaxometry methods in MRI. NMR IN BIOMEDICINE 2016; 29:841-861. [PMID: 27100142 DOI: 10.1002/nbm.3518] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 01/21/2016] [Accepted: 02/18/2016] [Indexed: 06/05/2023]
Abstract
Macromolecular degeneration and biochemical changes in tissue can be quantified using rotating frame relaxometry in MRI. It has been shown in several studies that the rotating frame longitudinal relaxation rate constant (R1ρ ) and the rotating frame transverse relaxation rate constant (R2ρ ) are sensitive biomarkers of phenomena at the cellular level. In this comprehensive review, existing MRI methods for probing the biophysical mechanisms that affect the rotating frame relaxation rates of the tissue (i.e. R1ρ and R2ρ ) are presented. Long acquisition times and high radiofrequency (RF) energy deposition into tissue during the process of spin-locking in rotating frame relaxometry are the major barriers to the establishment of these relaxation contrasts at high magnetic fields. Therefore, clinical applications of R1ρ and R2ρ MRI using on- or off-resonance RF excitation methods remain challenging. Accordingly, this review describes the theoretical and experimental approaches to the design of hard RF pulse cluster- and adiabatic RF pulse-based excitation schemes for accurate and precise measurements of R1ρ and R2ρ . The merits and drawbacks of different MRI acquisition strategies for quantitative relaxation rate measurement in the rotating frame regime are reviewed. In addition, this review summarizes current clinical applications of rotating frame MRI sequences. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Irtiza Ali Gilani
- Brain Research Unit, Department of Neuroscience and Biomedical Engineering, Aalto University, Aalto, Finland
- Advanced Magnetic Imaging Center, Aalto University, Aalto, Finland
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Raimo Sepponen
- Department of Electronics, School of Electrical Engineering, Aalto University, Aalto, Finland
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Srinivasan S, Ennis DB. Variable flip angle balanced steady-state free precession for lower SAR or higher contrast cardiac cine imaging. Magn Reson Med 2015; 71:1035-43. [PMID: 23629954 DOI: 10.1002/mrm.24764] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE Cardiac cine balanced steady-state free precession (bSSFP) imaging uses a high flip angle (FA) to obtain high blood-myocardium signal-to-noise and contrast-to-noise ratios (CNR). Use of high FAs, however, results in substantially increased SAR. Our objective was to develop a variable FA bSSFP cardiac cine imaging technique with: (1) low SAR and blood-myocardium CNR similar to conventional constant FA bSSFP (CFA-bSSFP) or (2) increased blood-myocardium CNR compared to CFA-bSSFP with similar SAR. METHODS Variable FA bSSFP cardiac cine imaging was achieved using an asynchronous k-space acquisition, which is asynchronous to the cardiac cycle (aVFA-bSSFP). Bloch simulations and phantom experiments were performed to compare the signal, resolution, and frequency response of the variable FA bSSFP and CFA-bSSFP schemes. Ten volunteers were imaged with different aVFA-bSSFP and asynchronous CFA-bSSFP schemes and compared to conventional segmented CFA-bSSFP. RESULTS The SAR of aVFA-bSSFP is significantly decreased by 36% compared to asynchronous CFA-bSSFP (1.9 ± 0.2 vs. 3.0 ± 0.2 W/kg, P < 10(-10)) for similar blood-myocardium CNR (34 ± 6 vs. 35 ± 9, P = 0.5). Alternately, the CNR of the aVFA-bSSFP is improved by 28% compared to asynchronous CFA-bSSFP (49 ± 9 vs. 38 ± 8, P < 10(-4)) with similar SAR (3.2 ± 0.5 vs. 3.3 ± 0.5 W/kg, P = 0.6). CONCLUSION aVFA-bSSFP can be used for lower SAR or higher contrast cardiac cine imaging compared to the conventional segmented CFA-bSSFP imaging.
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Affiliation(s)
- Subashini Srinivasan
- Department of Bioengineering, University of California, Los Angeles, California, USA; Department of Radiological Sciences, University of California, Los Angeles, California, USA
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5
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Srinivasan S, Wu HH, Sung K, Margolis DJA, Ennis DB. Fast 3D T2 -weighted imaging using variable flip angle transition into driven equilibrium (3D T2 -TIDE) balanced SSFP for prostate imaging at 3T. Magn Reson Med 2014; 74:442-51. [PMID: 25195659 DOI: 10.1002/mrm.25430] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 08/05/2014] [Accepted: 08/06/2014] [Indexed: 12/15/2022]
Abstract
PURPOSE Three-dimensional (3D) T2 -weighted fast spin echo (FSE) imaging of the prostate currently requires long acquisition times. Our objective was to develop a fast 3D T2 -weighted sequence for prostate imaging at 3T using a variable flip angle transition into driven equilibrium (T2 -TIDE) scheme. METHODS 3D T2 -TIDE uses interleaved spiral-out phase encode ordering to efficiently sample the ky -kz phase encodes and also uses the transient balanced steady-state free precession signal to acquire the center of k-space for T2 -weighted imaging. Bloch simulations and images from 10 healthy subjects were acquired to evaluate the performance of 3D T2 -TIDE compared to 3D FSE. RESULTS 3D T2 -TIDE images were acquired in 2:54 minutes compared to 7:02 minutes for 3D FSE with identical imaging parameters. The signal-to-noise ratio (SNR) efficiency was significantly higher for 3D T2 -TIDE compared to 3D FSE in nearly all tissues, including periprostatic fat (45 ± 12 vs. 31 ± 7, P < 0.01), gluteal fat (48 ± 8 vs. 41 ± 10, P = 0.12), right peripheral zone (20 ± 4 vs. 16 ± 8, P = 0.12), left peripheral zone (17 ± 2 vs. 12 ± 3, P < 0.01), and anterior fibromuscular stroma (12 ± 4 vs. 4 ± 2, P < 0.01). CONCLUSION 3D T2 -TIDE images of the prostate can be acquired quickly with SNR efficiency that exceeds that of 3D FSE.
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Affiliation(s)
- Subashini Srinivasan
- Department of Radiological Sciences, University of California, Los Angeles, California, USA.,Department of Bioengineering, University of California, Los Angeles, California, USA
| | - Holden H Wu
- Department of Radiological Sciences, University of California, Los Angeles, California, USA.,Department of Bioengineering, University of California, Los Angeles, California, USA.,Biomedical Physics Interdepartmental Program, University of California, Los Angeles, California, USA
| | - Kyunghyun Sung
- Department of Radiological Sciences, University of California, Los Angeles, California, USA.,Department of Bioengineering, University of California, Los Angeles, California, USA
| | - Daniel J A Margolis
- Department of Radiological Sciences, University of California, Los Angeles, California, USA
| | - Daniel B Ennis
- Department of Radiological Sciences, University of California, Los Angeles, California, USA.,Department of Bioengineering, University of California, Los Angeles, California, USA.,Biomedical Physics Interdepartmental Program, University of California, Los Angeles, California, USA
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Benkert T, Bartsch AJ, Blaimer M, Jakob PM, Breuer FA. Generating multiple contrasts using single-shot radial T1 sensitive and insensitive steady-state imaging. Magn Reson Med 2014; 73:2129-41. [PMID: 24975241 DOI: 10.1002/mrm.25337] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/07/2014] [Accepted: 06/05/2014] [Indexed: 11/11/2022]
Abstract
PURPOSE Recently, the (Resolution Enhanced-) T1 insensitive steady-state imaging (TOSSI) approach has been proposed for the fast acquisition of T2 -weighted images. This has been achieved by balanced steady-state free precession (bSSFP) imaging between unequally spaced inversion pulses. The purpose of this work is to present an extension of this technique, considerably increasing both the efficiency and possibilities of TOSSI. THEORY AND METHODS A radial trajectory in combination with an appropriate view-sharing reconstruction is used. Because each projection traverses the contrast defining k-space center, several different contrasts can be extracted from a single-shot measurement. These contrasts include various T2 -weightings and T2 /T1 -weighting if an even number of inversion pulses is used, while an odd number allow the generation of several images with predefined tissue types cancelled. RESULTS The approach is validated for brain and abdominal imaging at 3.0 Tesla. Results are compared with RE-TOSSI, bSSFP, and turbo spin-echo images and are shown to provide similar contrasts in a fraction of scan time. Furthermore, the potential utility of the approach is illustrated by images obtained from a brain tumor patient. CONCLUSION Radial T1 sensitive and insensitive steady-state imaging is able to generate multiple contrasts out of one single-shot measurement in a short scan time.
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Affiliation(s)
- Thomas Benkert
- Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany
| | - Andreas J Bartsch
- Department of Neuroradiology, University of Heidelberg, Heidelberg, Germany.,Department of Neuroradiology, University of Würzburg, Würzburg, Germany.,FMRIB Centre, University of Oxford, Oxford, United Kingdom
| | - Martin Blaimer
- Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany
| | - Peter M Jakob
- Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany.,Department of Experimental Physics 5, University of Würzburg, Würzburg, Germany
| | - Felix A Breuer
- Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany
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7
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Huang YCK, Huang TY, Chiu HC, Kuo TS, Hsueh CJ, Kao HW, Wang CW, Hsu HH, Juan CJ. Transition into driven equilibrium of the balanced steady-state free precession as an ultrafast multisection T2-weighted imaging of the brain. AJNR Am J Neuroradiol 2014; 35:1137-44. [PMID: 24722304 DOI: 10.3174/ajnr.a3863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Current T2-weighted imaging takes >3 minutes to perform, for which the ultrafast transition into driven equilibrium (TIDE) technique may be potentially helpful. This study qualitatively and quantitatively evaluates the imaging of transition into driven equilibrium of the balanced steady-state free precession (TIDE) compared with TSE and turbo gradient spin-echo on T2-weighted MR images. MATERIALS AND METHODS Thirty healthy volunteers were examined with T2-weighted images by using TIDE, TSE, and turbo gradient spin-echo sequences. Imaging was evaluated qualitatively by 2 independent observers on the basis of a 4-point rating scale regarding contrast characteristics and artifacts behavior. Image SNR and contrast-to-noise ratio were quantitatively assessed. RESULTS TIDE provided T2-weighted contrast similar to that in TSE and turbo gradient spin-echo with only one-eighth of the scan time. TIDE showed gray-white matter differentiation and iron-load sensitivity inferior that of TSE and turbo gradient spin-echo, but with improved motion artifacts reduction on qualitative scores. Nonmotion ghosting artifacts were uniquely found in TIDE images. The overall SNRs of TSE were 1.9-2.0 times those of turbo gradient spin-echo and 1.7-2.2 times of those of TIDE for brain tissue (P < .0001). TIDE had a higher contrast-to-noise ratio than TSE (P = .169) and turbo gradient spin-echo (P < .0001) regarding non-iron-containing gray matter versus white matter. TIDE had a lower contrast-to-noise ratio than turbo gradient spin-echo and TSE (P < .0001) between iron-containing gray matter and white matter. CONCLUSIONS TIDE provides T2-weighted images with reduced scan times and reduced motion artifacts compared with TSE and turbo gradient spin-echo with the trade-off of reduced SNR and poorer gray-white matter differentiation.
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Affiliation(s)
- Y-C K Huang
- From the Department of Electrical Engineering (Y.-C.K.H., T.-S.K.), National Taiwan University, Taipei, Taiwan, Republic of ChinaDepartment of Radiology (Y.-C.K.H., C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), Tri-Service General Hospital, Taipei, Taiwan, Republic of China
| | - T-Y Huang
- Department of Electrical Engineering (T.-Y.H.), National Taiwan University of Science and Technology, Taiwan, Republic of China
| | - H-C Chiu
- Graduate Institute of Design Science (H.-C.C.), Tatung University, Taipei, Taiwan, Republic of China
| | - T-S Kuo
- From the Department of Electrical Engineering (Y.-C.K.H., T.-S.K.), National Taiwan University, Taipei, Taiwan, Republic of China
| | - C-J Hsueh
- Department of Radiology (Y.-C.K.H., C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), Tri-Service General Hospital, Taipei, Taiwan, Republic of ChinaDepartment of Radiology (C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - H-W Kao
- Department of Radiology (Y.-C.K.H., C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), Tri-Service General Hospital, Taipei, Taiwan, Republic of ChinaDepartment of Radiology (C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - C-W Wang
- Department of Radiology (Y.-C.K.H., C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), Tri-Service General Hospital, Taipei, Taiwan, Republic of ChinaDepartment of Radiology (C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - H-H Hsu
- Department of Radiology (Y.-C.K.H., C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), Tri-Service General Hospital, Taipei, Taiwan, Republic of ChinaDepartment of Radiology (C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - C-J Juan
- Department of Radiology (Y.-C.K.H., C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), Tri-Service General Hospital, Taipei, Taiwan, Republic of ChinaDepartment of Radiology (C.-J.H., H.-W.K, C.-W.W., H.-H. H., C.-J.J.), National Defense Medical Center, Taipei, Taiwan, Republic of China.
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Corteville DMR, Kjørstad Å, Henzler T, Zöllner FG, Schad LR. Fourier decomposition pulmonary MRI using a variable flip angle balanced steady-state free precession technique. Magn Reson Med 2014; 73:1999-2004. [DOI: 10.1002/mrm.25293] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/10/2014] [Accepted: 04/24/2014] [Indexed: 11/08/2022]
Affiliation(s)
- D. M. R. Corteville
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim; Heidelberg University; Heidelberg Germany
| | - Å. Kjørstad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim; Heidelberg University; Heidelberg Germany
| | - T. Henzler
- Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim; Heidelberg University; Heidelberg Germany
| | - F. G. Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim; Heidelberg University; Heidelberg Germany
| | - L. R. Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim; Heidelberg University; Heidelberg Germany
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Xu D, Herzka DA, Gilson WD, McVeigh ER, Lewin JS, Weiss CR. MR-guided sclerotherapy of low-flow vascular malformations using T2 -weighted interrupted bSSFP (T2 W-iSSFP): comparison of pulse sequences for visualization and needle guidance. J Magn Reson Imaging 2014; 41:525-35. [PMID: 24395498 DOI: 10.1002/jmri.24552] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 11/22/2013] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Image-guided treatment of low-flow vascular (venous or lymphatic) malformations presents a challenging visualization problem, regardless of the imaging modality being used for guidance. The purpose of this study was to employ a new magnetic resonance imaging (MRI) sequence, T2 -weighted interrupted balanced steady-state free precession (T2 W-iSSFP), for real-time image guidance of needle insertion. MATERIALS AND METHODS T2 W-iSSFP uses variable flip angle balanced steady-state free precession (bSSFP, a.k.a. SSFP) to establish T2 -weighting and fat suppression. Swine (n = 3) and patients (n = 4, three female, all with venous malformations) were enrolled in the assessment. T2 -weighted turbo spin echo (T2 -TSE) with spectral adiabatic inversion recovery (SPAIR), SPAIR-T2 -TSE or T2 -TSE for short, was used as the reference. T2 -weighted half Fourier acquired single shot turbo spin echo (T2 -HASTE) with SPAIR (SPAIR-T2 -HASTE, T2 -HASTE for short), fat saturated bSSFP (FS-SSFP), and T2 W-iSSFP were imaged. Numeric metrics, namely, contrast-to-noise ratio (CNR) efficiency (CNR divided by the square root of acquisition time) and local sharpness (the reciprocal of edge width), were used to assess image quality. MR-guided sclerotherapy was performed on the same patients using real-time T2 W-iSSFP to guide needle insertion. RESULTS Comparing the visualization of needles in the images of swine, the local sharpness (mm(-1) ) was: 0.21 ± 0.06 (T2 -HASTE), 0.48 ± 0.02 (FS-SSFP), and 0.49 ± 0.03 (T2 W-iSSFP). T2 W-iSSFP is higher than T2 -HASTE (P < 0.001). For the patient images, their CNR efficiencies were: 797 ± 66 (T2 -HASTE), 281 ± 44 (FS-SSFP), and 860 ± 29 (T2 W-iSSFP). T2 W-iSSFP is higher than FS-SSFP (P < 0.02). The frame rate of T2 W-iSSFP was 2.5-3.5 frames per second. All MR-guided sclerotherapy procedures were successful, with all needles (six punctures) placed in the targets. CONCLUSION T2 W-iSSFP provides effective lesion identification and needle visualization. This new pulse sequence can be used for MR-guided sclerotherapy of low-flow vascular malformations. It may have potential use in other MR-guided procedures where heavily T2 -weighted real-time images are needed.
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Affiliation(s)
- Di Xu
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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10
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Bieri O, Scheffler K. Fundamentals of balanced steady state free precession MRI. J Magn Reson Imaging 2013; 38:2-11. [PMID: 23633246 DOI: 10.1002/jmri.24163] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 03/12/2013] [Indexed: 11/10/2022] Open
Affiliation(s)
- Oliver Bieri
- Division of Radiological Physics; Department of Radiology; University of Basel Hospital; Basel; Switzerland
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11
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Derakhshan JJ, Nour SG, Sunshine JL, Griswold MA, Duerk JL. Resolution enhanced T1-insensitive steady-state imaging. Magn Reson Med 2012; 68:421-9. [PMID: 22131264 PMCID: PMC3307911 DOI: 10.1002/mrm.23290] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 10/07/2011] [Accepted: 10/15/2011] [Indexed: 11/08/2022]
Abstract
Resolution enhanced T(1)-insensitive steady-state imaging (RE-TOSSI) is a new MRI pulse sequence for the generation of rapid T(2) contrast with high spatial resolution. TOSSI provides T(2) contrast by using nonequally spaced inversion pulses throughout a balanced steady-state free precession (SSFP) acquisition. In RE-TOSSI, these energy and time intensive adiabatic inversion pulses and associated magnetization preparation are removed from TOSSI after acquisition of the data around the center of k-space. Magnetization evolution simulations demonstrate T(2) contrast in TOSSI as well as reduction in the widening of the point spread function width (by up to a factor of 4) to a near ideal case for RE-TOSSI. Phantom experimentation is used to characterize and compare the contrast and spatial resolution properties of TOSSI, RE-TOSSI, balanced SSFP, Half-Fourier Acquisition Single-Shot Turbo Spin Echo (HASTE), and turbo spin echo and to optimize the fraction of k-space acquired using TOSSI. Comparison images in the abdomen and brain demonstrate similar contrast and improved spatial resolution in RE-TOSSI compared with TOSSI; comparison balanced SSFP, HASTE, and turbo spin echo images are provided. RE-TOSSI is capable of providing high spatial resolution T(2)-weighted images in 1 s or less per image.
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Affiliation(s)
- Jamal J. Derakhshan
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
- Department of Radiology, Case Western Reserve University/University Hospitals of Cleveland, Cleveland, Ohio
| | - Sherif G. Nour
- Department of Radiology, Emory University, Atlanta, Georgia (Current)
| | - Jeffrey L. Sunshine
- Department of Radiology, Case Western Reserve University/University Hospitals of Cleveland, Cleveland, Ohio
| | - Mark A. Griswold
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
- Department of Radiology, Case Western Reserve University/University Hospitals of Cleveland, Cleveland, Ohio
| | - Jeffrey L. Duerk
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
- Department of Radiology, Case Western Reserve University/University Hospitals of Cleveland, Cleveland, Ohio
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Schmitt P, Jakob PM, Kotas M, Flentje M, Haase A, Griswold MA. T-one insensitive steady state imaging: a framework for purely T2-weighted TrueFISP. Magn Reson Med 2011; 68:409-20. [PMID: 22131223 DOI: 10.1002/mrm.23239] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 08/18/2011] [Accepted: 09/08/2011] [Indexed: 01/17/2023]
Abstract
A new conceptual framework called T-one insensitive steady state imaging is proposed for fast generation of MR images with pure T(2) contrast. This is accomplished by imaging between nonequally spaced inversion pulses, with the magnetization vector alternatively residing in states parallel and antiparallel to B(0) for durations TP(i) and TA(i), respectively. With TP(i) and TA(i) adequately chosen, identical signal time evolution can be obtained for different T(1) values, i.e., T(1) contrast can efficiently be removed from resultant images. As a specific realization of this principle, T-one insensitive steady state imaging sequences are presented which use True free induction steady precession readout blocks between the inversion pulses. While the conventional True free induction steady precession signal time course would be determined by both T(2) and T(1), a pure T(2) dependence is realized with successfully suppressed influence of longitudinal relaxation, and images with essentially T(2) contrast alone are obtained. Analytical expressions are provided for the description of the ideal signal behavior, which help in creating pathways for sequence parameter optimization. The performance of the technique is analyzed with Bloch equation simulations. In vivo results obtained in healthy volunteers and brain tumor patients are presented.
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Affiliation(s)
- Peter Schmitt
- MR Application & Workflow Development, Siemens AG, Healthcare Sector, Erlangen, Germany
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13
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Deppe MH, Wild JM. Variable flip angle schedules in bSSFP imaging of hyperpolarized noble gases. Magn Reson Med 2011; 67:1656-64. [DOI: 10.1002/mrm.23155] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 06/13/2011] [Accepted: 07/25/2011] [Indexed: 11/12/2022]
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14
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Hoad CL, Cox EF, Gowland PA. Quantification of T
2
in the abdomen at 3.0 T using a T
2
-prepared balanced turbo field echo sequence. Magn Reson Med 2009; 63:356-64. [DOI: 10.1002/mrm.22203] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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15
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Improved SNR in linear reordered 2D bSSFP imaging using variable flip angles. Magn Reson Imaging 2009; 27:933-41. [DOI: 10.1016/j.mri.2009.01.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 12/15/2008] [Accepted: 01/29/2009] [Indexed: 11/18/2022]
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Abstract
Interest in advanced neuroimaging is growing and is certain to continue; new and faster sequences, better image quality, higher magnetic fields, and improved models of diffusion, perfusion, and functional connectivity are in constant development. The purpose of this article is to highlight recent advances in neuroimaging from two aspects: (1) those advances directly benefited by increases in field strength (increased T1, signal-to-noise ratio, magnetic susceptibility-sensitivity, and chemical shift) and how the increased signal-to-noise ratio can be used to trade off for other advantages and (2) those advances made in response to attempts to try to reduce the inherent artifacts encountered at higher field strengths (eg, reducing specific radiofrequency absorption in tissue and magnetic susceptibility).
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Affiliation(s)
- Michael E Moseley
- Radiological Sciences Laboratory, Lucas MRS Center, Department of Radiology, Stanford University Medical Center, 1201 Welch Road, Stanford, CA 94305, USA.
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Witschey WRT, Borthakur A, Elliott MA, Fenty M, Sochor MA, Wang C, Reddy R. T1rho-prepared balanced gradient echo for rapid 3D T1rho MRI. J Magn Reson Imaging 2008; 28:744-54. [PMID: 18777535 DOI: 10.1002/jmri.21444] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To develop a T1rho-prepared, balanced gradient echo (b-GRE) pulse sequence for rapid three-dimensional (3D) T1rho relaxation mapping within the time constraints of a clinical exam (<10 minutes), examine the effect of acquisition on the measured T1rho relaxation time and optimize 3D T1rho pulse sequences for the knee joint and spine. MATERIALS AND METHODS A pulse sequence consisting of inversion recovery-prepared, fat saturation, T1rho-preparation, and b-GRE image acquisition was used to obtain 3D volume coverage of the patellofemoral and tibiofemoral cartilage and lower lumbar spine. Multiple T1rho-weighted images at various contrast times (spin-lock pulse duration [TSL]) were used to construct a T1rho relaxation map in both phantoms and in the knee joint and spine in vivo. The transient signal decay during b-GRE image acquisition was corrected using a k-space filter. The T1rho-prepared b-GRE sequence was compared to a standard T1rho-prepared spin echo (SE) sequence and pulse sequence parameters were optimized numerically using the Bloch equations. RESULTS The b-GRE transient signal decay was found to depend on the initial T1rho-preparation and the corresponding T1rho map was altered by variations in the point spread function with TSL. In a two compartment phantom, the steady state response was found to elevate T1rho from 91.4+/-6.5 to 293.8+/-31 and 66.9+/-3.5 to 661+/-207 with no change in the goodness-of-fit parameter R2. Phase encoding along the longest cartilage dimension and a transient signal decay k-space filter retained T1rho contrast. Measurement of T1rho using the T1rho-prepared b-GRE sequence matches standard T1rho-prepared SE in the medial patellar and lateral patellar cartilage compartments. T1rho-preparedb-GRE T1rho was found to have low interscan variability between four separate scans. Mean patellar cartilage T1rho was elevated compared to femoral and tibial cartilage T1rho. CONCLUSION The T1rho-prepared b-GRE acquisition rapidly and reliably accelerates T1rho quantification of tissues offset partially by a TSL-dependent point spread function.
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Affiliation(s)
- Walter R T Witschey
- Metabolic Magnetic Resonance Research and Computing Center, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6100, USA.
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Bankson JA, Ji L, Ravoori M, Han L, Kundra V. Echo-planar imaging for MRI evaluation of intrathoracic tumors in murine models of lung cancer. J Magn Reson Imaging 2008; 27:57-62. [PMID: 18058933 DOI: 10.1002/jmri.21221] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To evaluate the efficacy of fast cardiac- and respiratory-gated MRI acquisition methods for noninvasive assessment of tumor volume in murine models of lung cancer. MATERIALS AND METHODS A total of 21 mice bearing either human small-cell (N417) or non-small-cell (H460) lung tumors were scanned using combinations of respiratory-gated computed tomography (CT) imaging, cardiac- and respiratory-gated multishot spin-echo echo-planar imaging (SE-EPI), and cardiac- and respiratory-gated spoiled gradient echo (SPGR). Tumor depiction at 4.7T was qualitatively and quantitatively compared with CT and tissue cross sections. MRI-based measures of tumor volume were compared with ex vivo measurement of tumor mass. RESULTS Tumors appeared hyperintense on T(2)-weighted EPI images, providing positive intrinsic contrast between tumors and surrounding tissues. Tumor boundaries were better distinguished by EPI and SPGR with T(1)-reducing contrast enhancement when tumor abutted other tissues than by CT or SPGR without contrast. Tumor volumes measured from EPI images correlate well with ex vivo measurements of tumor mass (P < 0.001, r(2) = 0.99) and volume (P < 0.01, r(2) = 0.98) over a wide range of tumor sizes. CONCLUSION Respiratory- and cardiac-gated multishot EPI enables accurate, noninvasive assessment of tumor in murine models of lung cancer using a sequence that requires approximately two minutes to complete.
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Affiliation(s)
- James A Bankson
- Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030-4009, USA.
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Pulse sequences and system interfaces for interventional and real-time MRI. J Magn Reson Imaging 2008; 27:267-75. [DOI: 10.1002/jmri.21268] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Aletras AH, Kellman P, Derbyshire JA, Arai AE. ACUT2E TSE-SSFP: A hybrid method for T2-weighted imaging of edema in the heart. Magn Reson Med 2008; 59:229-35. [DOI: 10.1002/mrm.21490] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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