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Saunders LC, Hughes PJC, Alabed S, Capener DJ, Marshall H, Vogel-Claussen J, van Beek EJR, Kiely DG, Swift AJ, Wild JM. Integrated Cardiopulmonary MRI Assessment of Pulmonary Hypertension. J Magn Reson Imaging 2022; 55:633-652. [PMID: 34350655 DOI: 10.1002/jmri.27849] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/21/2021] [Accepted: 05/24/2021] [Indexed: 11/12/2022] Open
Abstract
Pulmonary hypertension (PH) is a heterogeneous condition that can affect the lung parenchyma, pulmonary vasculature, and cardiac chambers. Accurate diagnosis often requires multiple complex assessments of the cardiac and pulmonary systems. MRI is able to comprehensively assess cardiac structure and function, as well as lung parenchymal, pulmonary vascular, and functional lung changes. Therefore, MRI has the potential to provide an integrated functional and structural assessment of the cardiopulmonary system in a single exam. Cardiac MRI is used in the assessment of PH in most large PH centers, whereas lung MRI is an emerging technique in patients with PH. This article reviews the current literature on cardiopulmonary MRI in PH, including cine MRI, black-blood imaging, late gadolinium enhancement, T1 mapping, myocardial strain analysis, contrast-enhanced perfusion imaging and contrast-enhanced MR angiography, and hyperpolarized gas functional lung imaging. This article also highlights recent developments in this field and areas of interest for future research including cardiac MRI-based diagnostic models, machine learning in cardiac MRI, oxygen-enhanced 1 H imaging, contrast-free 1 H perfusion and ventilation imaging, contrast-free angiography and UTE imaging. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 3.
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Affiliation(s)
- Laura C Saunders
- Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Paul J C Hughes
- Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Samer Alabed
- Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | | | - Helen Marshall
- Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Jens Vogel-Claussen
- Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany
| | | | - David G Kiely
- Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Andrew J Swift
- Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK.,Imaging, Sheffield Teaching Hospitals, Sheffield, UK
| | - Jim M Wild
- Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
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Park S, Kim EY, Sohn CH, Park J. Dynamic Contrast-Enhanced MR Angiography Exploiting Subspace Projection for Robust Angiogram Separation. IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:584-595. [PMID: 27810804 DOI: 10.1109/tmi.2016.2622715] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Dynamic contrast-enhanced magnetic resonance angiography (DCE MRA) has been widely used as a clinical routine for diagnostic assessment of vascular morphology and hemodynamics. It requires high spatial and temporal resolution to capture rapid variation of DCE signals within a limited imaging time. Subtraction-based approaches are typically employed to selectively delineate arteries while eliminating unwanted background signals. Nevertheless, in the presence of subject motion with time, conventional subtraction approaches suffer from incomplete background suppression that impairs the detectability of arteries. In this work, we propose a novel, DCE MRA method that exploits subspace projection (SP) based angiogram separation for robust background suppression. A new, SP-based DCE signal model is introduced, in which images are decomposed into stationary background tissues, motion-induced artifacts, and DCE angiograms of interest. Constrained image reconstruction with sparsity priors is performed to project motion-induced artifacts onto the predefined subspace while extracting DCE angiograms of interest. Simulations and experimental studies validate that the proposed method outperforms existing techniques with increasing reduction factors in suppressing artifacts and noise.
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Zhu Y, Guo Y, Lingala SG, Lebel RM, Law M, Nayak KS. GOCART: GOlden-angle CArtesian randomized time-resolved 3D MRI. Magn Reson Imaging 2015; 34:940-50. [PMID: 26707849 DOI: 10.1016/j.mri.2015.12.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 12/15/2015] [Accepted: 12/16/2015] [Indexed: 11/16/2022]
Abstract
PURPOSE To develop and evaluate a novel 3D Cartesian sampling scheme which is well suited for time-resolved 3D MRI using parallel imaging and compressed sensing. METHODS The proposed sampling scheme, termed GOlden-angle CArtesian Randomized Time-resolved (GOCART) 3D MRI, is based on golden angle (GA) Cartesian sampling, with random sampling of the ky-kz phase encode locations along each Cartesian radial spoke. This method was evaluated in conjunction with constrained reconstruction of retrospectively and prospectively undersampled in-vivo dynamic contrast enhanced (DCE) MRI data and simulated phantom data. RESULTS In in-vivo retrospective studies and phantom simulations, images reconstructed from phase encodes defined by GOCART were equal to or superior to those with Poisson disc or GA sampling schemes. Typical GOCART sampling tables were generated in <100ms. GOCART has also been successfully utilized prospectively to produce clinically valuable whole-brain DCE-MRI images. CONCLUSION GOCART is a practical and efficient sampling scheme for time-resolved 3D MRI. It shows great potential for highly accelerated DCE-MRI and is well suited to modern reconstruction methods such as parallel imaging and compressed sensing.
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Affiliation(s)
- Yinghua Zhu
- Ming Hsieh Department of Electrical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, USA.
| | - Yi Guo
- Ming Hsieh Department of Electrical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, USA
| | - Sajan Goud Lingala
- Ming Hsieh Department of Electrical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, USA
| | - R Marc Lebel
- Applied Science Laboratory, GE Healthcare, AB, Calgary, Canada; Foothills Medical Center, Calgary, Canada
| | - Meng Law
- Department of Radiology, Keck School of Medicine, University of Southern California Medical Center, Los Angeles, USA
| | - Krishna S Nayak
- Ming Hsieh Department of Electrical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, USA
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Wang K, Beatty PJ, Nagle SK, Reeder SB, Holmes JH, Rahimi MS, Bell LC, Korosec FR, Brittain JH. Application of direct virtual coil to dynamic contrast-enhanced MRI and MR angiography with data-driven parallel imaging. Magn Reson Med 2015; 71:783-9. [PMID: 23441013 DOI: 10.1002/mrm.24686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE To demonstrate the feasibility of direct virtual coil (DVC) in the setting of 4D dynamic imaging used in multiple clinical applications. THEORY AND METHODS Three dynamic imaging applications were chosen: pulmonary perfusion, liver perfusion, and peripheral MR angiography (MRA), with 18, 11, and 10 subjects, respectively. After view-sharing, the k-space data were reconstructed twice: once with channel-by-channel (CBC) followed by sum-of-squares coil combination and once with DVC. Images reconstructed using CBC and DVC were compared and scored based on overall image quality by two experienced radiologists using a five-point scale. RESULTS The CBC and DVC showed similar image quality in image domain. Time course measurements also showed good agreement in the temporal domain. CBC and DVC images were scored as equivalent for all pulmonary perfusion cases, all liver perfusion cases, and four of the 10 peripheral MRA cases. For the remaining six peripheral MRA cases, DVC were scored as slightly better (not clinically significant) than the CBC images by Radiologist A and as equivalent by Radiologist B. CONCLUSION For dynamic contrast-enhanced MR applications, it is clinically feasible to reduce image reconstruction time while maintaining image quality and time course measurement using the DVC technique.
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Affiliation(s)
- Kang Wang
- Global Applied Science Laboratory, GE Healthcare, Madison, Wisconsin, USA
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Cheng JY, Zhang T, Ruangwattanapaisarn N, Alley MT, Uecker M, Pauly JM, Lustig M, Vasanawala SS. Free-breathing pediatric MRI with nonrigid motion correction and acceleration. J Magn Reson Imaging 2014; 42:407-20. [PMID: 25329325 DOI: 10.1002/jmri.24785] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 10/06/2014] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To develop and assess motion correction techniques for high-resolution pediatric abdominal volumetric magnetic resonance images acquired free-breathing with high scan efficiency. MATERIALS AND METHODS First, variable-density sampling and radial-like phase-encode ordering were incorporated into the 3D Cartesian acquisition. Second, intrinsic multichannel butterfly navigators were used to measure respiratory motion. Lastly, these estimates are applied for both motion-weighted data-consistency in a compressed sensing and parallel imaging reconstruction, and for nonrigid motion correction using a localized autofocusing framework. With Institutional Review Board approval and informed consent/assent, studies were performed on 22 consecutive pediatric patients. Two radiologists independently scored the images for overall image quality, degree of motion artifacts, and sharpness of hepatic vessels and the diaphragm. The results were assessed using paired Wilcoxon test and weighted kappa coefficient for interobserver agreements. RESULTS The complete procedure yielded significantly better overall image quality (mean score of 4.7 out of 5) when compared to using no correction (mean score of 3.4, P < 0.05) and to using motion-weighted accelerated imaging (mean score of 3.9, P < 0.05). With an average scan time of 28 seconds, the proposed method resulted in comparable image quality to conventional prospective respiratory-triggered acquisitions with an average scan time of 91 seconds (mean score of 4.5). CONCLUSION With the proposed methods, diagnosable high-resolution abdominal volumetric scans can be obtained from free-breathing data acquisitions.
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Affiliation(s)
- Joseph Y Cheng
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA.,Department of Radiology, Stanford University, Stanford, California, USA
| | - Tao Zhang
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA.,Department of Radiology, Stanford University, Stanford, California, USA
| | | | - Marcus T Alley
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Martin Uecker
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA
| | - John M Pauly
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Michael Lustig
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA
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Okuaki T, Ishimoto T, Miyati T, Kobayashi S, Ishihara M, Kawakami M, Ogino T, Van Cauteren M. Separate pulmonary artery and vein magnetic resonance angiography by use of an arterial spin labeling method. Radiol Phys Technol 2014; 7:352-7. [PMID: 24906451 DOI: 10.1007/s12194-014-0272-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 05/18/2014] [Accepted: 05/18/2014] [Indexed: 12/01/2022]
Abstract
A separate pulmonary vein (PV) is difficult to depict with the commonly used bright-blood magnetic resonance angiography method. Until now, no study has described the depiction of peripheral PVs without the artery. Our purpose in this study was to develop an arterial spin labeling (ASL)-based magnetic resonance angiography sequence to depict the pulmonary artery (PA) and vein separately. We developed such a sequence by using two inversion recovery pulses. The first pulse was non-selective, and the second pulse was selective and was applied to the aorta and heart. All studies were conducted on a 1.5-T clinical magnetic resonance system with six different inversion times for seven healthy volunteers. For evaluation, we categorized the inversion times by using visual scoring. Then, we used the magnitude image to evaluate the PA, and we used the real image to evaluate the PV. For the PA, an inversion time of 300 ms had the lowest score (1.43), and the score changed with increasing times; an inversion time of 1,100 ms had the highest score (3.85). For the PV, an inversion time of 300 ms had the highest score (2.68), and the score decreased with increasing times. The results indicated that the PA and vein could be depicted separately by the use of an ASL-based magnetic resonance angiography method. The optimal inversion times for the PV and artery were 300 and 1,100 ms, respectively.
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Affiliation(s)
- Tomoyuki Okuaki
- Philips Healthcare, 2-13-37 Kohnan, Minato-ku, Tokyo, 108-8507, Japan,
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Liu J, Saloner D. Accelerated MRI with CIRcular Cartesian UnderSampling (CIRCUS): a variable density Cartesian sampling strategy for compressed sensing and parallel imaging. Quant Imaging Med Surg 2014; 4:57-67. [PMID: 24649436 DOI: 10.3978/j.issn.2223-4292.2014.02.01] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 02/12/2014] [Indexed: 11/14/2022]
Abstract
PURPOSE This study proposes and evaluates a novel method for generating efficient undersampling patterns for 3D Cartesian acquisition with compressed sensing (CS) and parallel imaging (PI). METHODS Image quality achieved with schemes that accelerate data acquisition, including CS and PI, are sensitive to the design of the specific undersampling scheme used. Ideally random sampling is required to recover MR images from undersampled data with CS. In practice, pseudo-random sampling schemes are usually applied. Radial or spiral sampling either for Cartesian or non-Cartesian acquisitions has been using because of its favorable features such as interleaving flexibility. In this study, we propose to undersample data on the ky-kz plane of the 3D Cartesian acquisition by circularly selecting sampling points in a way that maintains the features of both random and radial or spiral sampling. RESULTS The proposed sampling scheme is shown to outperform conventional random and radial or spiral samplings for 3D Cartesian acquisition and is found to be comparable to advanced variable-density Poisson-Disk sampling (vPDS) while retaining interleaving flexibility for dynamic imaging, based on the results with retrospective undersampling. Our preliminary results with the prospective implementation of the proposed undersampling strategy demonstrated its favorable features. CONCLUSIONS The proposed undersampling patterns for 3D Cartesian acquisition possess the desirable properties of randomization and radial or spiral trajectories. It provides easy implementation, flexible sampling, and high accuracy of image reconstruction with CS and PI.
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Affiliation(s)
- Jing Liu
- 1 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA ; 2 Radiology Service, VA Medical Center, San Francisco, California, USA
| | - David Saloner
- 1 Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA ; 2 Radiology Service, VA Medical Center, San Francisco, California, USA
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Wang K, Schiebler ML, Francois CJ, Del Rio AM, Cornejo MD, Bell LC, Korosec FR, Brittain JH, Holmes JH, Nagle SK. Pulmonary perfusion MRI using interleaved variable density sampling and HighlY constrained cartesian reconstruction (HYCR). J Magn Reson Imaging 2013; 38:751-6. [PMID: 23349079 DOI: 10.1002/jmri.24018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 12/05/2012] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To demonstrate the feasibility of performing single breathhold, noncardiac gated, ultrafast, high spatial-temporal resolution whole chest MR pulmonary perfusion imaging in humans. MATERIALS AND METHODS Eight subjects (five male, three female) were scanned with the proposed method on a 3 Tesla clinical scanner using a 32-channel phased-array coil. Seven (88%) were healthy volunteers, and one was a patient volunteer with sarcoidosis. The peak lung enhancement phase for each subject was scored for gravitational effect, peak parenchymal enhancement and severity of artifacts by three cardiothoracic radiologists independently. RESULTS All studies were successfully performed by MR technologists without any additional training. Mean parenchymal signal was very good, measuring 0.78 ± 0.13 (continuous scale, 0 = "none" → 1 = "excellent"). Mean level of motion artifacts was low, measuring 0.13 ± 0.08 (continuous scale, 0 = "none" → 1 = "severe"). CONCLUSION It is feasible to perform single breathhold, noncardiac gated, ultrafast, high spatial-temporal resolution whole chest MR pulmonary perfusion imaging in humans.
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Affiliation(s)
- Kang Wang
- Global Applied Science Laboratory, GE Healthcare, Madison, WI 53705, USA.
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Du J, Karimi A, Wu Y, Korosec FR, Grist TM, Mistretta CA. Automated vessel segmentation using cross-correlation and pooled covariance matrix analysis. Magn Reson Imaging 2011; 29:391-400. [DOI: 10.1016/j.mri.2010.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Revised: 03/17/2010] [Accepted: 09/03/2010] [Indexed: 10/18/2022]
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10
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Wang K, Busse RF, Holmes JH, Beatty PJ, Brittain JH, Francois CJ, Reeder SB, Du J, Korosec FR. Interleaved variable density sampling with a constrained parallel imaging reconstruction for dynamic contrast-enhanced MR angiography. Magn Reson Med 2011; 66:428-36. [PMID: 21360740 DOI: 10.1002/mrm.22814] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Revised: 12/13/2010] [Accepted: 12/14/2010] [Indexed: 11/09/2022]
Abstract
For MR applications such as contrast-enhanced MR angiography, it is desirable to achieve simultaneously high spatial and temporal resolution. The current clinical standard uses view-sharing methods combined with parallel imaging; however, this approach still provides limited spatial and temporal resolution. To improve on the clinical standard, we present an interleaved variable density (IVD) sampling method that pseudorandomly undersamples each individual frame of a 3D Cartesian ky-kz plane combined with parallel imaging acceleration. From this dataset, time-resolved images are reconstructed with a method that combines parallel imaging with a multiplicative constraint. Total acceleration factors on the order of 20 are achieved for contrast-enhanced MR angiography of the lower extremities, and improvements in temporal fidelity of the depiction of the contrast bolus passage are demonstrated relative to the clinical standard.
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Affiliation(s)
- Kang Wang
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705-2275, USA
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Boussel L, Cernicanu A, Geerts L, Gamondes D, Khouatra C, Cottin V, Revel D, Douek P. 4D time-resolved magnetic resonance angiography for noninvasive assessment of pulmonary arteriovenous malformations patency. J Magn Reson Imaging 2011; 32:1110-6. [PMID: 21031516 DOI: 10.1002/jmri.22384] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To assess the capability of four-dimensional (4D) time-resolved magnetic resonance angiography (MRA) to assess pulmonary arteriovenous malformations (PAVMs) patency by analyzing pulmonary arterial and venous enhancement kinetics. MATERIALS AND METHODS Seven patients with eight documented patent PAVMs underwent a 4D-MRA with keyhole and viewsharing compression at 3T with the following parameters: spatial resolution 0.87 × 0.87 × 1.4 mm(3); field of view 500 × 350 × 238 mm(3); dynamic scan time (temporal resolution) 1.2 seconds; total acquisition time 18.1 seconds for six dynamic datasets (6 × 1.2 sec + reference scan: 10.9 sec). All images were reviewed by two experienced radiologists. Image quality was rated on a qualitative 5-point scale (1: not assessable to 5: excellent). Signal value was measured on cross-sectional planes for the afferent arteries and efferent veins of the PAVM, and for normal reference healthy arteries and veins. The difference in time to peak for each coupled artery/vein (dTTPav) was calculated and compared with a Mann-Whitney test between PAVMs and reference vessels. RESULTS Mean image quality was 3.2 ± 0.9. dTTPav was significantly smaller in PAVMs (0.15 ± 0.76 sec) than in reference vessels (3.75 ± 1.62 sec), P < 0.001. CONCLUSION 4D-MRA is a promising tool for noninvasive assessment of PAVM patency.
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Affiliation(s)
- Loic Boussel
- Department of Radiology, Louis Pradel Hospital, CREATIS, UMR CNRS 5515, INSERM U630, Lyon, France.
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Kim KA, Herigault G, Kim MJ, Chung YE, Hong HS, Choi SY. Three-dimensional contrast-enhanced hepatic MR imaging: Comparison between a centric technique and a linear approach with partial Fourier along both slice and phase directions. J Magn Reson Imaging 2010; 33:160-6. [DOI: 10.1002/jmri.22436] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Jeong HJ, Eddleman CS, Shah S, Seiberlich N, Griswold MA, Batjer HH, Carr JC, Carroll TJ. Accelerating time-resolved MRA with multiecho acquisition. Magn Reson Med 2010; 63:1520-8. [PMID: 20512855 DOI: 10.1002/mrm.22373] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A new four-dimensional magnetic resonance angiography (MRA) technique called contrast-enhanced angiography with multiecho and radial k-space is introduced, which accelerates the acquisition using multiecho while maintaining a high spatial resolution and increasing the signal-to-noise ratio (SNR). An acceleration factor of approximately 2 is achieved without parallel imaging or undersampling by multiecho (i.e., echo-planar imaging) acquisition. SNR is gained from (1) longer pulse repetition times, which allow more time for T(1) regrowth; (2) decreased specific absorption rate, which allows use of flip angles that maximize contrast at high field; and (3) minimized effects of a transient contrast bolus signal with a shorter temporal footprint. Simulations, phantom studies, and in vivo scans were performed. Contrast-enhanced angiography with multiecho and radial k-space can be combined with parallel imaging techniques such as Generalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) to provide additional 2-fold acceleration in addition to higher SNR to trade off for parallel imaging. This technique can be useful in diagnosing vascular lesions where accurate dynamic information is necessary.
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Affiliation(s)
- Hyun J Jeong
- Biomedical Engineering, Northwestern University, Chicago, Illinois, USA
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Prieto C, Uribe S, Razavi R, Atkinson D, Schaeffter T. 3D undersampled golden‐radial phase encoding for DCE‐MRA using inherently regularized iterative SENSE. Magn Reson Med 2010; 64:514-26. [DOI: 10.1002/mrm.22446] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Claudia Prieto
- King's College London, Division of Imaging Sciences, NIHR Biomedical Research Centre at Guy's & St Thomas' Foundation Trust London, United Kingdom
| | - Sergio Uribe
- King's College London, Division of Imaging Sciences, NIHR Biomedical Research Centre at Guy's & St Thomas' Foundation Trust London, United Kingdom
- Pontificia Universidad Católica de Chile, Radiology Department, School of Medicine, Center for Biomedical Imaging, Santiago, Chile
| | - Reza Razavi
- King's College London, Division of Imaging Sciences, NIHR Biomedical Research Centre at Guy's & St Thomas' Foundation Trust London, United Kingdom
| | - David Atkinson
- Centre for Medical Image Computing, University College London, London, United Kingdom
| | - Tobias Schaeffter
- King's College London, Division of Imaging Sciences, NIHR Biomedical Research Centre at Guy's & St Thomas' Foundation Trust London, United Kingdom
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Shu Y, Bernstein MA, Huston J, Rettmann D. Contrast-enhanced intracranial magnetic resonance angiography with a spherical shells trajectory and online gridding reconstruction. J Magn Reson Imaging 2009; 30:1101-9. [PMID: 19856444 DOI: 10.1002/jmri.21938] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To evaluate the feasibility of applying the shells trajectory to single-phase contrast-enhanced magnetic resonance angiography. MATERIALS AND METHOD Several methods were developed to overcome the challenges of the clinical implementation of shells including off-resonance blurring (eg, from lipid signal), aliasing artifacts, and long reconstruction times. These methods included: 1) variable TR with variable readout length to reduce fat signal and off-resonance blurring; 2) variable sampling density to suppress aliasing artifacts while minimizing acquisition time penalty; and 3) an online 3D gridding algorithm that reconstructed an 8-channel, 240(3) image volume set. Both phantom and human studies were performed to establish the initial feasibility of the methods. RESULTS Phantom and human study results demonstrated the effectiveness of the proposed methods. Shells with variable TR and readout length further suppressed the fat signal compared to the fixed-TR shells acquisition. Reduced image aliasing was achieved with minimal scan time penalty when a variable sampling density technique was used. The fast online reconstruction algorithm completed in 2 minutes at the scanner console, providing a timely image display in a clinical setting. CONCLUSION It was demonstrated that the use of the shells trajectory is feasible in a clinical setting to acquire intracranial angiograms with high spatial resolution. Preliminary results demonstrate effective venous suppression in the cavernous sinuses and jugular vein region.
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Affiliation(s)
- Yunhong Shu
- Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905, USA.
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