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Rauch J, Laun FB, Bachert P, Ladd ME, Kuder TA. Compensation of concomitant field effects in double diffusion encoding by means of added oscillating gradients. Magn Reson Imaging 2024; 105:133-141. [PMID: 37939973 DOI: 10.1016/j.mri.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/04/2023] [Indexed: 11/10/2023]
Abstract
Maxwell or concomitant fields imprint additional phases on the transverse magnetization. This concomitant phase may cause severe image artifacts like signal voids or distort the quantitative parameters due to the induced intravoxel dephasing. In particular, double diffusion encoding (DDE) schemes with two pairs of bipolar diffusion-weighting gradients separated by a refocusing radiofrequency (RF) pulse are prone to concomitant field-induced artifacts. In this work, a method for reducing concomitant field effects in these DDE sequences based on additional oscillating gradients is presented. These oscillating gradient pulses obtained by constrained optimization were added to the original gradient waveforms. The modified sequences reduced the accumulated concomitant phase without significant changes in the original sequence characteristics. The proposed method was applied to a DDE acquisition scheme consisting of 60 pairs of diffusion wave vectors. For phantom as well as for in vivo experiments, a considerable increase in the signal-to-noise ratio (SNR) was obtained. For phantom measurements with a diffusion weighting of b = 2000 s/mm2 for each of the gradient pairs, an SNR increase of up to 40% was observed for a transversal slice that had a distance of 5 cm from the isocenter. For equivalent slice parameters, in vivo measurements in the brain of a healthy volunteer exhibited an increase in SNR of up to 35% for b = 750 s/mm2 for each weighting. These findings are supported by corresponding simulations, which also predict a positive effect on the SNR. In summary, the presented method leads to an SNR gain without additional RF refocusing pulses.
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Affiliation(s)
- Julian Rauch
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; MPI for Nuclear Physics, Max-Planck-Society, Saupfercheckweg 1, 69117 Heidelberg, Germany; Faculty of Physics and Astronomy, Heidelberg University, Im Neuenheimer Feld 226, 69120 Heidelberg, Germany
| | - Frederik B Laun
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Maximiliansplatz 3, 91054 Erlangen, Germany
| | - Peter Bachert
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Faculty of Physics and Astronomy, Heidelberg University, Im Neuenheimer Feld 226, 69120 Heidelberg, Germany
| | - Mark E Ladd
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Faculty of Physics and Astronomy, Heidelberg University, Im Neuenheimer Feld 226, 69120 Heidelberg, Germany; Faculty of Medicine, Heidelberg University, Im Neuenheimer Feld 672, 69120 Heidelberg, Germany
| | - Tristan A Kuder
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Faculty of Physics and Astronomy, Heidelberg University, Im Neuenheimer Feld 226, 69120 Heidelberg, Germany.
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Buonincontri G, Biagi L, Retico A, Cecchi P, Cosottini M, Gallagher FA, Gómez PA, Graves MJ, McLean MA, Riemer F, Schulte RF, Tosetti M, Zaccagna F, Kaggie JD. Multi-site repeatability and reproducibility of MR fingerprinting of the healthy brain at 1.5 and 3.0 T. Neuroimage 2019; 195:362-372. [PMID: 30923028 DOI: 10.1016/j.neuroimage.2019.03.047] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 03/08/2019] [Accepted: 03/20/2019] [Indexed: 12/19/2022] Open
Abstract
Fully-quantitative MR imaging methods are useful for longitudinal characterization of disease and assessment of treatment efficacy. However, current quantitative MRI protocols have not been widely adopted in the clinic, mostly due to lengthy scan times. Magnetic Resonance Fingerprinting (MRF) is a new technique that can reconstruct multiple parametric maps from a single fast acquisition in the transient state of the MR signal. Due to the relative novelty of this technique, the repeatability and reproducibility of quantitative measurements obtained using MRF has not been extensively studied. Our study acquired test/retest data from the brains of nine healthy volunteers, each scanned on five MRI systems (two at 3.0 T and three at 1.5 T, all from a single vendor) located at two different centers. The pulse sequence and reconstruction algorithm were the same for all acquisitions. After registration of the MRF-derived M0, T1 and T2 maps to an anatomical atlas, coefficients-of-variation (CVs) were computed to assess test/retest repeatability and inter-site reproducibility in each voxel, while a General Linear Model (GLM) was used to determine the voxel-wise variability between all confounders, which included test/retest, subject, field strength and site. Our analysis demonstrated an excellent repeatability (CVs of 2-3% for T1, 5-8% for T2, 3% for normalized-M0) and a good reproducibility (CVs of 3-8% for T1, 8-14% for T2, 5% for normalized-M0) in grey and white matter.
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Affiliation(s)
- Guido Buonincontri
- IMAGO7 Foundation, Pisa, Italy; IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Laura Biagi
- IMAGO7 Foundation, Pisa, Italy; IRCCS Fondazione Stella Maris, Pisa, Italy
| | | | - Paolo Cecchi
- Department of Radiology, University of Pisa, Italy
| | | | | | - Pedro A Gómez
- Munich School of Bioengineering, Technical University of Munich, Germany
| | - Martin J Graves
- Department of Radiology, University of Cambridge, United Kingdom
| | - Mary A McLean
- Cancer Research UK Cambridge Institute, University of Cambridge, United Kingdom
| | - Frank Riemer
- Department of Radiology, University of Cambridge, United Kingdom
| | | | - Michela Tosetti
- IMAGO7 Foundation, Pisa, Italy; IRCCS Fondazione Stella Maris, Pisa, Italy.
| | - Fulvio Zaccagna
- Department of Radiology, University of Cambridge, United Kingdom
| | - Joshua D Kaggie
- Department of Radiology, University of Cambridge, United Kingdom
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Ryu K, Shin J, Lee H, Kim JH, Kim DH. Multi-echo GRE-based conductivity imaging using Kalman phase estimation method. Magn Reson Med 2018; 81:702-710. [DOI: 10.1002/mrm.27376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 04/18/2018] [Accepted: 05/04/2018] [Indexed: 01/26/2023]
Affiliation(s)
- Kanghyun Ryu
- Department of Electrical and Electronic Engineering; Yonsei University; Seoul Korea
| | - Jaewook Shin
- Department of Electrical and Electronic Engineering; Yonsei University; Seoul Korea
| | - Hongpyo Lee
- Department of Electrical and Electronic Engineering; Yonsei University; Seoul Korea
| | - Jun-Hyeong Kim
- Department of Electrical and Electronic Engineering; Yonsei University; Seoul Korea
| | - Dong-Hyun Kim
- Department of Electrical and Electronic Engineering; Yonsei University; Seoul Korea
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Development of Correction for Signal-to-Noise Ratio Using a T2* With Improved Phase Method. J Comput Assist Tomogr 2018; 42:117-123. [DOI: 10.1097/rct.0000000000000644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ruschke S, Eggers H, Kooijman H, Diefenbach MN, Baum T, Haase A, Rummeny EJ, Hu HH, Karampinos DC. Correction of phase errors in quantitative water-fat imaging using a monopolar time-interleaved multi-echo gradient echo sequence. Magn Reson Med 2016; 78:984-996. [PMID: 27797100 DOI: 10.1002/mrm.26485] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/06/2016] [Accepted: 09/08/2016] [Indexed: 12/11/2022]
Abstract
PURPOSE To propose a phase error correction scheme for monopolar time-interleaved multi-echo gradient echo water-fat imaging that allows accurate and robust complex-based quantification of the proton density fat fraction (PDFF). METHODS A three-step phase correction scheme is proposed to address a) a phase term induced by echo misalignments that can be measured with a reference scan using reversed readout polarity, b) a phase term induced by the concomitant gradient field that can be predicted from the gradient waveforms, and c) a phase offset between time-interleaved echo trains. Simulations were carried out to characterize the concomitant gradient field-induced PDFF bias and the performance estimating the phase offset between time-interleaved echo trains. Phantom experiments and in vivo liver and thigh imaging were performed to study the relevance of each of the three phase correction steps on PDFF accuracy and robustness. RESULTS The simulation, phantom, and in vivo results showed in agreement with the theory an echo time-dependent PDFF bias introduced by the three phase error sources. The proposed phase correction scheme was found to provide accurate PDFF estimation independent of the employed echo time combination. CONCLUSION Complex-based time-interleaved water-fat imaging was found to give accurate and robust PDFF measurements after applying the proposed phase error correction scheme. Magn Reson Med 78:984-996, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Stefan Ruschke
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | | | | | - Maximilian N Diefenbach
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Thomas Baum
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Axel Haase
- Institute of Medical Engineering, Technical University of Munich, Garching, Germany
| | - Ernst J Rummeny
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Houchun H Hu
- Radiology, Phoenix Children's Hospital, Phoenix, Arizona, USA
| | - Dimitrios C Karampinos
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
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Colgan TJ, Hernando D, Sharma SD, Reeder SB. The effects of concomitant gradients on chemical shift encoded MRI. Magn Reson Med 2016; 78:730-738. [PMID: 27650137 DOI: 10.1002/mrm.26461] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/19/2016] [Accepted: 08/22/2016] [Indexed: 01/07/2023]
Abstract
PURPOSE The purpose of this work was to characterize the effects of concomitant gradients (CGs) on chemical shift encoded (CSE)-based estimation of B0 field map, proton density fat fraction (PDFF), and R2*. THEORY A theoretical framework was used to determine the effects of CG-induced phase errors on CSE-MRI data. METHODS Simulations, phantom experiments, and in vivo experiments were conducted at 3 Tesla to assess the effects of CGs on quantitative CSE-MRI techniques. Correction of phase errors attributable to CGs was also investigated to determine whether these effects could be removed. RESULTS Phase errors attributed to CGs introduce errors in the estimation of B0 field map, PDFF, and R2*. Phantom and in vivo experiments demonstrated that CGs can introduce estimation errors greater than 30 Hz in the B0 field map, 10% in PDFF, and 16 s-1 in R2*, 16 cm off isocenter. However, CG phase correction before parameter estimation was able to reduce estimation errors to less than 10 Hz in the B0 field map, 1% in PDFF, and 2 s-1 in R2*. CONCLUSION CG effects can impact CSE-MRI, leading to inaccurate estimation of B0 field map, PDFF, and R2*. However, correction for phase errors caused by CGs improve the accuracy of quantitative parameters estimated from CSE-MRI acquisitions. Magn Reson Med 78:730-738, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Timothy J Colgan
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.,Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Diego Hernando
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.,Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA
| | - Samir D Sharma
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
| | - Scott B Reeder
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.,Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA.,Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, USA.,Department of Medicine, University of Wisconsin, Madison, Wisconsin, USA.,Department of Emergency Medicine, University of Wisconsin, Madison, Wisconsin, USA
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