1
|
Kollmeier JM, Tan Z, Joseph AA, Kalentev O, Voit D, Merboldt KD, Frahm J. Real-time multi-directional flow MRI using model-based reconstructions of undersampled radial FLASH - A feasibility study. NMR IN BIOMEDICINE 2019; 32:e4184. [PMID: 31580524 DOI: 10.1002/nbm.4184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 08/12/2019] [Accepted: 08/15/2019] [Indexed: 06/10/2023]
Abstract
The purpose of this work was to develop an acquisition and reconstruction technique for two- and three-directional (2d and 3d) phase-contrast flow MRI in real time. A previous real-time MRI technique for one-directional (1d) through-plane flow was extended to 2d and 3d flow MRI by introducing in-plane flow sensitivity. The method employs highly undersampled radial FLASH sequences with sequential acquisitions of two or three flow-encoding datasets and one flow-compensated dataset. Echo times are minimized by merging the waveforms of flow-encoding and radial imaging gradients. For each velocity direction individually, model-based reconstructions by regularized nonlinear inversion jointly estimate an anatomical image, a set of coil sensitivities and a phase-contrast velocity map directly. The reconstructions take advantage of a dynamic phase reference obtained by interpolating consecutive flow-compensated acquisitions. Validations include pulsatile flow phantoms as well as in vivo studies of the human aorta at 3 T. The proposed method offers cross-sectional 2d and 3d flow MRI of the human aortic arch at 53 and 67 ms resolution, respectively, without ECG synchronization and during free breathing. The in-plane resolution was 1.5 × 1.5 mm2 and the slice thickness 6 mm. In conclusion, real-time multi-directional flow MRI offers new opportunities to study complex human blood flow without the risk of combining differential phase (i.e., velocity) information from multiple heartbeats as for ECG-gated data. The method would benefit from a further reduction of acquisition time and accelerated computing to allow for extended clinical trials.
Collapse
Affiliation(s)
- Jost M Kollmeier
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Zhengguo Tan
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany
| | - Oleksandr Kalentev
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Dirk Voit
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - K Dietmar Merboldt
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany
| |
Collapse
|
2
|
Benkert T, Tian Y, Huang C, DiBella EVR, Chandarana H, Feng L. Optimization and validation of accelerated golden-angle radial sparse MRI reconstruction with self-calibrating GRAPPA operator gridding. Magn Reson Med 2017; 80:286-293. [PMID: 29193380 DOI: 10.1002/mrm.27030] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 11/02/2017] [Accepted: 11/10/2017] [Indexed: 12/24/2022]
Abstract
PURPOSE Golden-angle radial sparse parallel (GRASP) MRI reconstruction requires gridding and regridding to transform data between radial and Cartesian k-space. These operations are repeatedly performed in each iteration, which makes the reconstruction computationally demanding. This work aimed to accelerate GRASP reconstruction using self-calibrating GRAPPA operator gridding (GROG) and to validate its performance in clinical imaging. METHODS GROG is an alternative gridding approach based on parallel imaging, in which k-space data acquired on a non-Cartesian grid are shifted onto a Cartesian k-space grid using information from multicoil arrays. For iterative non-Cartesian image reconstruction, GROG is performed only once as a preprocessing step. Therefore, the subsequent iterative reconstruction can be performed directly in Cartesian space, which significantly reduces computational burden. Here, a framework combining GROG with GRASP (GROG-GRASP) is first optimized and then compared with standard GRASP reconstruction in 22 prostate patients. RESULTS GROG-GRASP achieved approximately 4.2-fold reduction in reconstruction time compared with GRASP (∼333 min versus ∼78 min) while maintaining image quality (structural similarity index ≈ 0.97 and root mean square error ≈ 0.007). Visual image quality assessment by two experienced radiologists did not show significant differences between the two reconstruction schemes. With a graphics processing unit implementation, image reconstruction time can be further reduced to approximately 14 min. CONCLUSION The GRASP reconstruction can be substantially accelerated using GROG. This framework is promising toward broader clinical application of GRASP and other iterative non-Cartesian reconstruction methods. Magn Reson Med 80:286-293, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Thomas Benkert
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Ye Tian
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA.,Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah, USA
| | - Chenchan Huang
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Edward V R DiBella
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Hersh Chandarana
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Li Feng
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| |
Collapse
|
3
|
K-space trajectory mapping and its application for ultrashort Echo time imaging. Magn Reson Imaging 2016; 36:68-76. [PMID: 27742433 DOI: 10.1016/j.mri.2016.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/22/2016] [Accepted: 10/05/2016] [Indexed: 11/21/2022]
Abstract
MR images are affected by system delays and gradient field imperfections which induce discrepancies between prescribed and actual k-space trajectories. This could be even more critical for non-Cartesian data acquisitions where even a small deviation from the assumed k-space trajectory results in severe image degradation and artifacts. Knowledge of the actual k-space trajectories is therefore crucial and can be incorporated in the reconstruction of high quality non-Cartesian images. A novel MR method for the calibration of actual gradient waveforms was developed using a combination of phase encoding increments and subsequent detection of the exact time point at which the corresponding trajectory is crossing the k-space origin. The measured sets of points were fitted to a parametrical model to calculate the complete actual acquisition trajectory. Measurements performed on phantoms and volunteers, positioned both in- and off-isocenter of the magnet, clearly demonstrate the improvement in reconstructed ultrashort echo time (UTE) images, when information from calibration of k-space sampling trajectories is employed in the MR image reconstruction procedure. The unique feature of the proposed method is its robustness and simple experimental setup, making it suitable for quick acquisition trajectory calibration procedures e.g. for non-Cartesian radial fast imaging.
Collapse
|
4
|
Nayak KS, Nielsen JF, Bernstein MA, Markl M, D Gatehouse P, M Botnar R, Saloner D, Lorenz C, Wen H, S Hu B, Epstein FH, N Oshinski J, Raman SV. Cardiovascular magnetic resonance phase contrast imaging. J Cardiovasc Magn Reson 2015; 17:71. [PMID: 26254979 PMCID: PMC4529988 DOI: 10.1186/s12968-015-0172-7] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/16/2015] [Indexed: 11/10/2022] Open
Abstract
Cardiovascular magnetic resonance (CMR) phase contrast imaging has undergone a wide range of changes with the development and availability of improved calibration procedures, visualization tools, and analysis methods. This article provides a comprehensive review of the current state-of-the-art in CMR phase contrast imaging methodology, clinical applications including summaries of past clinical performance, and emerging research and clinical applications that utilize today's latest technology.
Collapse
Affiliation(s)
- Krishna S Nayak
- Ming Hsieh Department of Electrical Engineering, University of Southern California, 3740 McClintock Ave, EEB 406, Los Angeles, California, 90089-2564, USA.
| | - Jon-Fredrik Nielsen
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
| | | | - Michael Markl
- Department of Radiology, Northwestern University, Chicago, IL, USA.
| | - Peter D Gatehouse
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.
| | - Rene M Botnar
- Cardiovascular Imaging, Imaging Sciences Division, Kings's College London, London, UK.
| | - David Saloner
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
| | - Christine Lorenz
- Center for Applied Medical Imaging, Siemens Corporation, Baltimore, MD, USA.
| | - Han Wen
- Imaging Physics Laboratory, National Heart Lung and Blood Institute, Bethesda, MD, USA.
| | - Bob S Hu
- Palo Alto Medical Foundation, Palo Alto, CA, USA.
| | - Frederick H Epstein
- Departments of Radiology and Biomedical Engineering, University of Virginia, Charlottesville, VA, USA.
| | - John N Oshinski
- Departments of Radiology and Biomedical Engineering, Emory University School of Medicine, Atlanta, GA, USA.
| | - Subha V Raman
- Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH, USA.
| |
Collapse
|
5
|
Körperich H, Barth P, Gieseke J, Müller K, Burchert W, Esdorn H, Kececioglu D, Beerbaum P, Laser KT. Impact of respiration on stroke volumes in paediatric controls and in patients after Fontan procedure assessed by MR real-time phase-velocity mapping. Eur Heart J Cardiovasc Imaging 2014; 16:198-209. [PMID: 25246504 DOI: 10.1093/ehjci/jeu179] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
AIMS Blood flow rate quantification using two-dimensional phase-contrast MRI (PC-MRI) results in averaging of flow information due to long acquisition times precluding the examination of short-term effects. The aim of this study was to determine respiration-related flow rate variations by non-electrocardiographic triggered real-time phase-contrast MRI (PC-MRI). METHODS AND RESULTS Real-time PC-MRI was applied to study respiration-driven blood flow fluctuations in the ascending aorta (AAo), superior vena cava (SVC), and inferior vena cava (IVC) under normal and forced breathing in 33 healthy children and 10 Fontan patients. Respiration-dependent flow rates were virtually generated by dividing the respiration curve into four segments: expiration, end-expiration, inspiration, and end-inspiration. Whereas in volunteers aortic flow rate was elevated during end-expiration (5.6 ± 3.0%) and decreased during end-inspiration (-5.8 ± 3.5%) in relation to mean blood flow (P < 0.05), highest flow was detected during inspiration in SVC (10.5 ± 14.1%) and IVC (22.5 ± 12.1%) and lowest flow during expiration (-11.6 ± 13.5%, -13.2 ± 14.1%, P < 0.05). Differences were increased under forced breathing in AAo (10.4 ± 5.5%, -7.4 ± 6.5%, P < 0.05) and SVC (40.0 ± 30.3%, -30.0 ± 19.2%, P < 0.05), whereas were unchanged in IVC (16.5 ± 23.6%, -13.7 ± 21.6%, P = n.s.). Regarding patients, respiratory-dependent flow rate variability was increased and had to be related to the patient's individual quality of Fontan circulation. CONCLUSION Real-time PC-MRI allows a physiological assessment of respiratory-related flow rate fluctuations in healthy subjects as well as in Fontan patients. Its capability for detection of short-term effects in clinical routine was demonstrated.
Collapse
Affiliation(s)
- Hermann Körperich
- Institute for Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstraße 11, D-32545 Bad Oeynhausen, Germany
| | - Peter Barth
- Institute for Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstraße 11, D-32545 Bad Oeynhausen, Germany
| | | | - Katja Müller
- Center for Congenital Heart Defects, Heart and Diabetes Centre Northrhine-Westfalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany
| | - Wolfgang Burchert
- Institute for Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstraße 11, D-32545 Bad Oeynhausen, Germany
| | - Hermann Esdorn
- Institute for Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstraße 11, D-32545 Bad Oeynhausen, Germany
| | - Deniz Kececioglu
- Center for Congenital Heart Defects, Heart and Diabetes Centre Northrhine-Westfalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany
| | - Philipp Beerbaum
- Medizinische Hochschule Hannover, Kinderheilkunde, Pädiatrische Kardiologie und Pädiatrische Intensivmedizin, Hannover, Germany
| | - Kai Thorsten Laser
- Center for Congenital Heart Defects, Heart and Diabetes Centre Northrhine-Westfalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany
| |
Collapse
|
6
|
Trotier AJ, Lefrançois W, Ribot EJ, Thiaudiere E, Franconi JM, Miraux S. Time-resolved TOF MR angiography in mice using a prospective 3D radial double golden angle approach. Magn Reson Med 2014; 73:984-94. [DOI: 10.1002/mrm.25201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 02/11/2014] [Accepted: 02/11/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Aurelien J. Trotier
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université Bordeaux Segalen; Bordeaux Cedex France
| | - William Lefrançois
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université Bordeaux Segalen; Bordeaux Cedex France
| | - Emeline J. Ribot
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université Bordeaux Segalen; Bordeaux Cedex France
| | - Eric Thiaudiere
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université Bordeaux Segalen; Bordeaux Cedex France
| | - Jean-Michel Franconi
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université Bordeaux Segalen; Bordeaux Cedex France
| | - Sylvain Miraux
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université Bordeaux Segalen; Bordeaux Cedex France
| |
Collapse
|
7
|
Santelli C, Schaeffter T, Kozerke S. Radial k-t SPIRiT: autocalibrated parallel imaging for generalized phase-contrast MRI. Magn Reson Med 2013; 72:1233-45. [PMID: 24258701 DOI: 10.1002/mrm.25030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 09/20/2013] [Accepted: 10/12/2013] [Indexed: 11/06/2022]
Abstract
PURPOSE To extend SPIRiT to additionally exploit temporal correlations for highly accelerated generalized phase-contrast MRI and to compare the performance of the proposed radial k-t SPIRiT method relative to frame-by-frame SPIRiT and radial k-t GRAPPA reconstruction for velocity and turbulence mapping in the aortic arch. THEORY AND METHODS Free-breathing navigator-gated two-dimensional radial cine imaging with three-directional multi-point velocity encoding was implemented and fully sampled data were obtained in the aortic arch of healthy volunteers. Velocities were encoded with three different first gradient moments per axis to permit quantification of mean velocity and turbulent kinetic energy. Velocity and turbulent kinetic energy maps from up to 14-fold undersampled data were compared for k-t SPIRiT, frame-by-frame SPIRiT, and k-t GRAPPA relative to the fully sampled reference. RESULTS Using k-t SPIRiT, improvements in magnitude and velocity reconstruction accuracy were found. Temporally resolved magnitude profiles revealed a reduction in spatial blurring with k-t SPIRiT compared with frame-by-frame SPIRiT and k-t GRAPPA for all velocity encodings, leading to improved estimates of turbulent kinetic energy. CONCLUSION k-t SPIRiT offers improved reconstruction accuracy at high radial undersampling factors and hence facilitates the use of generalized phase-contrast MRI for routine use.
Collapse
Affiliation(s)
- Claudio Santelli
- Imaging Sciences and Biomedical Engineering, King's College, London, United Kingdom; Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | | | | |
Collapse
|