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Vučić D, Bijelić N, Rođak E, Rajc J, Dumenčić B, Belovari T, Mihić D, Selthofer-Relatić K. Right Heart Morphology and Its Association With Excessive and Deficient Cardiac Visceral Adipose Tissue. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2021; 15:11795468211041330. [PMID: 34602829 PMCID: PMC8485260 DOI: 10.1177/11795468211041330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 07/11/2021] [Indexed: 11/21/2022]
Abstract
Visceral adipose tissue is an independent risk factor for the development of atherosclerotic coronary disease, arterial hypertension, diabetes and metabolic syndrome. Right heart morphology often involves the presence of adipose tissue, which can be quantified by non-invasive imaging methods. The last decade brought a wealth of new insights into the function and morphology of adipose tissue, with great emphasis on its role in the pathogenesis of heart disease. Cardiac adipose tissue is involved in thermogenesis, mechanical protection of the heart and energy storage. However, it can also be an endocrine organ that synthesises numerous pro-inflammatory and anti-inflammatory cytokines, the effect of which is accomplished by paracrine and vasocrine mechanisms. Visceral adipose tissue has several compartments that differ in their embryological origin and vascularisation. Deficiency of cardiac adipose tissue, often due to chronic pathological conditions such as oncological diseases or chronic infectious diseases, predicts increased mortality and morbidity. To date, knowledge about the influence of visceral adipose tissue on cardiac morphology is limited, especially the effect on the morphology of the right heart in a state of excess or deficient visceral adipose tissue.
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Affiliation(s)
- Domagoj Vučić
- Department for Internal Medicine, Division of Cardiology, General Hospital Doctor Josip Benčević, Slavonski Brod, Croatia
| | - Nikola Bijelić
- Department for Histology and Embriology, Faculty of Medicine, University Josip Juraj Strossmayer in Osijek, Osijek, Croatia
| | - Edi Rođak
- Department for Histology and Embriology, Faculty of Medicine, University Josip Juraj Strossmayer in Osijek, Osijek, Croatia
| | - Jasmina Rajc
- Department for Pathology and Forensic Medicine, University Hospital Center Osijek, Osijek, Croatia.,Department for Pathology, Faculty of Medicine, University Josip Juraj Strossmayer in Osijek, Osijek, Croatia
| | - Boris Dumenčić
- Department for Pathology and Forensic Medicine, University Hospital Center Osijek, Osijek, Croatia.,Department for Pathology, Faculty of Medicine, University Josip Juraj Strossmayer in Osijek, Osijek, Croatia
| | - Tatjana Belovari
- Department for Histology and Embriology, Faculty of Medicine, University Josip Juraj Strossmayer in Osijek, Osijek, Croatia
| | - Damir Mihić
- Department of Intensive Care Medicine, University Center Hospital Osijek, Osijek, Croatia.,Department for Internal Medicine, Faculty of Medicine, University Josip Juraj Strossmayer in Osijek, Osijek, Croatia
| | - Kristina Selthofer-Relatić
- Department for Internal Medicine, Faculty of Medicine, University Josip Juraj Strossmayer in Osijek, Osijek, Croatia.,Department for Heart and Vascular Diseases, University Center Hospital Osijek, Osijek, Croatia
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2
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Montalt-Tordera J, Kowalik G, Gotschy A, Steeden J, Muthurangu V. Rapid 3D whole-heart cine imaging using golden ratio stack of spirals. Magn Reson Imaging 2020; 72:1-7. [PMID: 32562742 DOI: 10.1016/j.mri.2020.06.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/14/2020] [Accepted: 06/11/2020] [Indexed: 11/16/2022]
Abstract
Three-dimensional cine imaging provides a wealth of information about cardiac anatomy and function, but its use in the clinical environment is limited because data acquisition is very time consuming. In this work, a free-breathing 3D whole-heart cine imaging framework was developed using a time-efficient stack of spirals trajectory and accelerated reconstruction. Two suitable view ordering methods are considered with different spacing between k-space readouts in the partition dimension: uniform and tiny golden ratio based. A simulation study suggested the latter did not present any benefits in terms of similarity to the true image. The proposed method was subsequently tested on 10 prospective subjects and compared with conventional multi-slice breath-hold imaging. Image quality was evaluated using objective and subjective scores and ventricular measurements were compared to assess clinical accuracy. Image quality was lower in the proposed technique than in breath-hold images but good agreement was found in clinically relevant ventricular measurements. In addition, the proposed method was fast to acquire, required minimal planning and provided full anatomical coverage with isotropic resolution.
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Affiliation(s)
| | | | - Alexander Gotschy
- Great Ormond Street Hospital, London, UK; Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.
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3
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Topping GJ, Hundshammer C, Nagel L, Grashei M, Aigner M, Skinner JG, Schulte RF, Schilling F. Acquisition strategies for spatially resolved magnetic resonance detection of hyperpolarized nuclei. MAGMA (NEW YORK, N.Y.) 2020; 33:221-256. [PMID: 31811491 PMCID: PMC7109201 DOI: 10.1007/s10334-019-00807-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 10/08/2019] [Accepted: 11/21/2019] [Indexed: 12/13/2022]
Abstract
Hyperpolarization is an emerging method in magnetic resonance imaging that allows nuclear spin polarization of gases or liquids to be temporarily enhanced by up to five or six orders of magnitude at clinically relevant field strengths and administered at high concentration to a subject at the time of measurement. This transient gain in signal has enabled the non-invasive detection and imaging of gas ventilation and diffusion in the lungs, perfusion in blood vessels and tissues, and metabolic conversion in cells, animals, and patients. The rapid development of this method is based on advances in polarizer technology, the availability of suitable probe isotopes and molecules, improved MRI hardware and pulse sequence development. Acquisition strategies for hyperpolarized nuclei are not yet standardized and are set up individually at most sites depending on the specific requirements of the probe, the object of interest, and the MRI hardware. This review provides a detailed introduction to spatially resolved detection of hyperpolarized nuclei and summarizes novel and previously established acquisition strategies for different key areas of application.
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Affiliation(s)
- Geoffrey J Topping
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Christian Hundshammer
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Luca Nagel
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Martin Grashei
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Maximilian Aigner
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Jason G Skinner
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | | | - Franz Schilling
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.
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Nomura T, Niwa T, Ozawa S, Oguma J, Shibukawa S, Imai Y. The Visibility of the Terminal Thoracic Duct Into the Venous System Using MR Thoracic Ductography with Balanced Turbo Field Echo Sequence. Acad Radiol 2019; 26:550-554. [PMID: 29748046 DOI: 10.1016/j.acra.2018.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 04/17/2018] [Accepted: 04/17/2018] [Indexed: 12/30/2022]
Abstract
RATIONALE AND OBJECTIVES Magnetic resonance thoracic ductography (MRTD) with balanced turbo field echo (bTFE) can visualize both the thoracic duct and its surrounding vessels. This study aimed to investigate the visibility of the terminal thoracic duct into the venous system in the subclavian region using MRTD with bTFE. MATERIALS AND METHODS MRTD was performed with bTFE as a preoperative workup comprising respiratory gating on a 1.5-T magnetic resonance system for patients with esophageal cancer. The portion and the number of terminal thoracic ducts into the venous system and preterminal branching in the left subclavian region were assessed using MRTD in 132 patients. The confidence level of the visibility using MRTD was also evaluated. RESULTS The most frequent terminal portion of the thoracic duct was the jugulovenous angle (92 patients, 69.7%), followed by the subclavian vein (27 patients, 20.5%) and the internal jugular vein (8 patients, 6.1%). Four patients also exhibited double entry of the thoracic duct into the venous system. The preterminal branching was single in 96 patients (72.7%) and multiple in 36 patients (27.3%). The confidence level of the visibility of the thoracic duct using MRTD was absolutely certain in 112 patients (84.8%) and was somewhat certain in 20 patients (15.2%). CONCLUSIONS MRTD with bTFE is a robust imaging modality to visualize the terminal portion of the thoracic duct into the venous system in the subclavian region.
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Affiliation(s)
- Takakiyo Nomura
- Department of Diagnostic Radiology, Tokai University School of Medicine, 143 Shimokasuya, Isehara, 259-1193, Japan
| | - Tetsu Niwa
- Department of Diagnostic Radiology, Tokai University School of Medicine, 143 Shimokasuya, Isehara, 259-1193, Japan.
| | - Soji Ozawa
- Department of Gastroenterological Surgery, Tokai University School of Medicine, Isehara, Japan
| | - Junya Oguma
- Department of Gastroenterological Surgery, Tokai University School of Medicine, Isehara, Japan
| | - Shuhei Shibukawa
- Department of Radiology, Tokai University Hospital, Isehara, Japan
| | - Yutaka Imai
- Department of Diagnostic Radiology, Tokai University School of Medicine, 143 Shimokasuya, Isehara, 259-1193, Japan
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Slawig A, Wech T, Ratz V, Neubauer H, Bley T, Köstler H. Frequency-modulated bSSFP for phase-sensitive separation of water and fat. Magn Reson Imaging 2018; 53:82-88. [PMID: 29902564 DOI: 10.1016/j.mri.2018.06.005] [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: 12/05/2017] [Revised: 04/27/2018] [Accepted: 06/10/2018] [Indexed: 10/28/2022]
Abstract
Our study proposes the use of a frequency-modulated acquisition which suppresses banding artefacts in combination with a phase-sensitive water-fat separation algorithm. The performance of the phase-sensitive separation for standard bSSFP, complex sum combination thereof, and frequency-modulated bSSFP were compared in in vivo measurements of the upper and lower legs at 1.5 and 3 T. It is shown, that the standard acquisition suffered from banding artefacts and major swaps between tissues. The dual-acquisition bSSFP could alleviate banding artefacts and only minor swaps occurred, but it comes at the expense of a doubled acquisition. In the frequency-modulated acquisitions all banding artefacts and the associated phase jumps were eliminated and no swaps between tissues occurred. It therefore provides a means to robustly separate water and fat, in one single radial bSSFP scan, using the phase-sensitive approach, even in the presence of high field inhomogeneities.
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Affiliation(s)
- Anne Slawig
- University of Würzburg, Department of Diagnostic and Interventional Radiology, Oberdürrbacher Str. 6, 97080 Würzburg, Germany.
| | - Tobias Wech
- University of Würzburg, Department of Diagnostic and Interventional Radiology, Oberdürrbacher Str. 6, 97080 Würzburg, Germany
| | - Valentin Ratz
- University of Würzburg, Department of Diagnostic and Interventional Radiology, Oberdürrbacher Str. 6, 97080 Würzburg, Germany
| | - Henning Neubauer
- University of Würzburg, Department of Diagnostic and Interventional Radiology, Oberdürrbacher Str. 6, 97080 Würzburg, Germany; SRH Clinic of Radiology, Albert-Schweitzer-Str. 2, 98527 Suhl, Germany
| | - Thorsten Bley
- University of Würzburg, Department of Diagnostic and Interventional Radiology, Oberdürrbacher Str. 6, 97080 Würzburg, Germany
| | - Herbert Köstler
- University of Würzburg, Department of Diagnostic and Interventional Radiology, Oberdürrbacher Str. 6, 97080 Würzburg, Germany
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Fatty Images of the Heart: Spectrum of Normal and Pathological Findings by Computed Tomography and Cardiac Magnetic Resonance Imaging. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5610347. [PMID: 29503824 PMCID: PMC5818975 DOI: 10.1155/2018/5610347] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 12/05/2017] [Indexed: 01/07/2023]
Abstract
Ectopic cardiac fatty images are not rarely detected incidentally by computed tomography and cardiac magnetic resonance, or by exams focused on the heart as in general thoracic imaging evaluations. A correct interpretation of these findings is essential in order to recognize their normal or pathological meaning, focusing on the eventually associated clinical implications. The development of techniques such as computed tomography and cardiac magnetic resonance allowed a detailed detection and evaluation of adipose tissue within the heart. This pictorial review illustrates the most common characteristics of cardiac fatty images by computed tomography and cardiac magnetic resonance, in a spectrum of normal and pathological conditions ranging from physiological adipose images to diseases presenting with cardiac fatty foci. Physiologic intramyocardial adipose tissue may normally be present in healthy adults, being not related to cardiac affections and without any clinical consequence. However cardiac fatty images may also be the expression of various diseases, comprehending arrhythmogenic right ventricular dysplasia, postmyocardial infarction lipomatous metaplasia, dilated cardiomyopathy, and lipomatous hypertrophy of the interatrial septum. Fatty neoplasms of the heart as lipoma and liposarcoma are also described.
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7
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Nomura T, Niwa T, Koizumi J, Shibukawa S, Ono S, Imai Y. Magnetic resonance thoracic ductography assessment of serial changes in the thoracic duct after the intake of a fatty meal. J Anat 2017; 232:509-514. [PMID: 29226328 DOI: 10.1111/joa.12761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2017] [Indexed: 11/28/2022] Open
Abstract
The thoracic duct, a terminal lymph vessel, is thought to dilate after the intake of a fatty meal. However, this physiological change has not been well explored in vivo. Therefore, the present study aimed to assess serial changes in the thoracic duct after the intake of a fatty meal using magnetic resonance thoracic ductography (MRTD). Eight healthy volunteers were subjected to one MRTD scan before a fatty meal and eight serial MRTD scans every hour thereafter. The cross-sectional areas of the thoracic duct were estimated using MRTD measurements of the diameters of the thoracic duct at the upper edge of the aortic arch, the tracheal bifurcation, the mid-point between the tracheal bifurcation and the left part of the diaphragm and the left part of the diaphragm. The change-rates in these areas were calculated before and after the fatty meal intake, and the maximal change-rate and timing of its achievement were determined for each subject. The summed change-rates in the four portions of the thoracic duct ranged from -40.1 to 81.3%, with maximal change-rates for each subject ranging from 22.8 to 81.3% (mean, 50.4%). Although individual variations were observed, most subjects (88.9%) exhibited a maximal change-rate at 4-6 h after meal intake, with subsequent decreases at 7-8 h. In conclusion, MRTD revealed a tendency toward thoracic duct enlargement at 4-6 h after the intake of a fatty meal, followed by contraction.
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Affiliation(s)
- Takakiyo Nomura
- Department of Diagnostic Radiology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Tetsu Niwa
- Department of Diagnostic Radiology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Jun Koizumi
- Department of Diagnostic Radiology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
| | - Shuhei Shibukawa
- Department of Radiology, Tokai University Hospital, Isehara, Kanagawa, Japan
| | - Shun Ono
- Department of Diagnostic Radiology, Tokai University School of Medicine, Isehara, Kanagawa, Japan.,Department of Surgery, Yale School of Medicine, New Haven, CT, USA
| | - Yutaka Imai
- Department of Diagnostic Radiology, Tokai University School of Medicine, Isehara, Kanagawa, Japan
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8
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Koktzoglou I, Edelman RR. Radial fast interrupted steady-state (FISS) magnetic resonance imaging. Magn Reson Med 2017; 79:2077-2086. [PMID: 28856788 DOI: 10.1002/mrm.26881] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 07/28/2017] [Accepted: 07/31/2017] [Indexed: 11/06/2022]
Abstract
PURPOSE To report a highly interrupted radial variant of balanced steady-state free precession (bSSFP) imaging, termed fast interrupted steady-state (FISS), for decreasing flow artifact as well as fat signal conspicuity with respect to bSSFP, and saturation effects vis-à-vis fast low-angle shot (FLASH) imaging. METHODS Numerical simulations, phantom studies, and human studies were conducted to examine the imaging contrast, off-resonance behavior, and flow properties of FISS. Human studies applied FISS for cine cardiac imaging and ungated nonenhanced MR angiography (MRA) of the legs, neck, and brain. Comparisons were made with bSSFP and FLASH imaging. RESULTS Simulations revealed that FISS retains the high signal levels of bSSFP for stationary on-resonant spins, while reducing undesirable signal heterogeneity from flowing spins. Phantom studies agreed with the simulations, and showed that FISS reduces fat signal and flow artifact with respect to bSSFP imaging. FISS imaging in human subjects agreed with the simulations and phantom studies, and showed reduced saturation artifact compared with FLASH imaging. CONCLUSION FISS imaging reduces flow artifact and fat signal conspicuity with respect to bSSFP imaging, and ameliorates arterial signal saturation observed with FLASH imaging. Potential clinical applications include fat-suppressed cine imaging and ungated nonenhanced MRA. Magn Reson Med 79:2077-2086, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Ioannis Koktzoglou
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,The University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
| | - Robert R Edelman
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.,Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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Shang H, Sukumar S, von Morze C, Bok RA, Marco-Rius I, Kerr A, Reed GD, Milshteyn E, Ohliger MA, Kurhanewicz J, Larson PEZ, Pauly JM, Vigneron DB. Spectrally selective three-dimensional dynamic balanced steady-state free precession for hyperpolarized C-13 metabolic imaging with spectrally selective radiofrequency pulses. Magn Reson Med 2016; 78:963-975. [PMID: 27770458 DOI: 10.1002/mrm.26480] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 08/30/2016] [Accepted: 09/02/2016] [Indexed: 12/12/2022]
Abstract
PURPOSE Balanced steady-state free precession (bSSFP) sequences can provide superior signal-to-noise ratio efficiency for hyperpolarized (HP) carbon-13 (13 C) magnetic resonance imaging by efficiently utilizing the nonrecoverable magnetization, but managing their spectral response is challenging in the context of metabolic imaging. A new spectrally selective bSSFP sequence was developed for fast imaging of multiple HP 13 C metabolites with high spatiotemporal resolution. THEORY AND METHODS This novel approach for bSSFP spectral selectivity incorporates optimized short-duration spectrally selective radiofrequency pulses within a bSSFP pulse train and a carefully chosen repetition time to avoid banding artifacts. RESULTS The sequence enabled subsecond 3D dynamic spectrally selective imaging of 13 C metabolites of copolarized [1-13 C]pyruvate and [13 C]urea at 2-mm isotropic resolution, with excellent spectral selectivity (∼100:1). The sequence was successfully tested in phantom studies and in vivo studies with normal mice. CONCLUSION This sequence is expected to benefit applications requiring dynamic volumetric imaging of metabolically active 13 C compounds at high spatiotemporal resolution, including preclinical studies at high field and, potentially, clinical studies. Magn Reson Med 78:963-975, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Hong Shang
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.,UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA
| | - Subramaniam Sukumar
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Cornelius von Morze
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Robert A Bok
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Irene Marco-Rius
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Adam Kerr
- Electrical Engineering, Stanford University, Stanford, California, USA
| | | | - Eugene Milshteyn
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.,UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA
| | - Michael A Ohliger
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - John Kurhanewicz
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.,UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA
| | - Peder E Z Larson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.,UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA
| | - John M Pauly
- Electrical Engineering, Stanford University, Stanford, California, USA
| | - Daniel B Vigneron
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.,UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, California, USA
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10
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Revisiting the Potential of Alternating Repetition Time Balanced Steady-State Free Precession Imaging of the Abdomen at 3 T. Invest Radiol 2016; 51:560-8. [DOI: 10.1097/rli.0000000000000275] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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11
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Mazzoli V, Nederveen AJ, Oudeman J, Sprengers A, Nicolay K, Strijkers GJ, Verdonschot N. Water and fat separation in real-time MRI of joint movement with phase-sensitive bSSFP. Magn Reson Med 2016; 78:58-68. [DOI: 10.1002/mrm.26341] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 06/20/2016] [Accepted: 06/20/2016] [Indexed: 01/04/2023]
Affiliation(s)
- Valentina Mazzoli
- Biomedical NMR, Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven The Netherlands
- Department of Radiology; Academic Medical Center; Amsterdam The Netherlands
- Orthopaedic Research Lab; Radboud University Medical Center; Nijmegen The Netherlands
| | - Aart J. Nederveen
- Department of Radiology; Academic Medical Center; Amsterdam The Netherlands
| | - Jos Oudeman
- Department of Radiology; Academic Medical Center; Amsterdam The Netherlands
| | - Andre Sprengers
- Orthopaedic Research Lab; Radboud University Medical Center; Nijmegen The Netherlands
- Laboratory of Biomechanical Engineering; University of Twente; Enschede The Netherlands
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven The Netherlands
| | - Gustav J. Strijkers
- Biomedical NMR, Department of Biomedical Engineering; Eindhoven University of Technology; Eindhoven The Netherlands
- Biomedical Engineering and Physics; Academic Medical Center; Amsterdam The Netherlands
| | - Nico Verdonschot
- Orthopaedic Research Lab; Radboud University Medical Center; Nijmegen The Netherlands
- Laboratory of Biomechanical Engineering; University of Twente; Enschede The Netherlands
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12
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Mozes FE, Tunnicliffe EM, Pavlides M, Robson MD. Influence of fat on liver T1 measurements using modified Look-Locker inversion recovery (MOLLI) methods at 3T. J Magn Reson Imaging 2016; 44:105-11. [PMID: 26762615 PMCID: PMC4982078 DOI: 10.1002/jmri.25146] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 12/21/2015] [Indexed: 01/23/2023] Open
Abstract
PURPOSE To characterize the effect of fat on modified Look-Locker inversion recovery (MOLLI) T1 maps of the liver. The balanced steady-state free precession (bSSFP) sequence causes water and fat signals to have opposite phase when repetition time (TR) = 2.3 msec at 3T. In voxels that contain both fat and water, the MOLLI T1 measurement is influenced by the choice of TR. MATERIALS AND METHODS MOLLI T1 measurements of the liver were simulated using the Bloch equations while varying the hepatic lipid content (HLC). Phantom scans were performed on margarine phantoms, using both MOLLI and spin echo inversion recovery sequences. MOLLI T1 at 3T and HLC were determined in patients (n = 8) before and after bariatric surgery. RESULTS At 3T, with HLC in the 0-35% range, higher fat fraction values lead to longer MOLLI T1 values when TR = 2.3 msec. Patients were found to have higher MOLLI T1 at elevated HLC (T1 = 929 ± 97 msec) than at low HLC (T1 = 870 ± 44 msec). CONCLUSION At 3T, MOLLI T1 values are affected by HLC, substantially changing MOLLI T1 in a clinically relevant range of fat content. J. Magn. Reson. Imaging 2016;44:105-111.
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Affiliation(s)
- Ferenc E Mozes
- University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Elizabeth M Tunnicliffe
- University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Michael Pavlides
- University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, John Radcliffe Hospital, Oxford, UK
- Translational Gastroenterology Unit, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Matthew D Robson
- University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, John Radcliffe Hospital, Oxford, UK
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13
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Nomura T, Niwa T, Kazama T, Sekiguchi T, Okazaki T, Shibukawa S, Nishio H, Obara M, Imai Y. Balanced Turbo Field Echo with Extended k-space Sampling: A Fast Technique for the Thoracic Ductography. Magn Reson Med Sci 2016; 15:405-410. [PMID: 27001397 PMCID: PMC5608115 DOI: 10.2463/mrms.tn.2015-0111] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We evaluated the visibility of the thoracic duct by fast balanced turbo field echo with extended k-space sampling (bTFEe). The thoracic duct of 10 healthy volunteers was scanned by bTFEe using a 1.5-T magnetic resonance imaging (MRI), which was acquired in approximately 2 minutes. Three-dimensional (3D) turbo spin-echo (TSE) was obtained for comparison. The thoracic duct including draining location of the venous system was overall well visualized on bTFEe, compared to TSE.
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Affiliation(s)
- Takakiyo Nomura
- Department of Radiology, Tokai University School of Medicine
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14
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Ding X, Pang J, Ren Z, Diaz-Zamudio M, Jiang C, Fan Z, Berman DS, Li D, Terzopoulos D, Slomka PJ, Dey D. Automated pericardial fat quantification from coronary magnetic resonance angiography: feasibility study. J Med Imaging (Bellingham) 2016; 3:014002. [PMID: 26958578 PMCID: PMC4757750 DOI: 10.1117/1.jmi.3.1.014002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 01/22/2016] [Indexed: 11/14/2022] Open
Abstract
Pericardial fat volume (PFV) is emerging as an important parameter for cardiovascular risk stratification. We propose a hybrid approach for automated PFV quantification from water/fat-resolved whole-heart noncontrast coronary magnetic resonance angiography (MRA). Ten coronary MRA datasets were acquired. Image reconstruction and phase-based water-fat separation were conducted offline. Our proposed algorithm first roughly segments the heart region on the original image using a simplified atlas-based segmentation with four cases in the atlas. To get exact boundaries of pericardial fat, a three-dimensional graph-based segmentation is used to generate fat and nonfat components on the fat-only image. The algorithm then selects the components that represent pericardial fat. We validated the quantification results on the remaining six subjects and compared them with manual quantifications by an expert reader. The PFV quantified by our algorithm was [Formula: see text], compared to [Formula: see text] by the expert reader, which were not significantly different ([Formula: see text]) and showed excellent correlation ([Formula: see text],[Formula: see text]). The mean absolute difference in PFV between the algorithm and the expert reader was [Formula: see text]. The mean value of the paired differences was [Formula: see text] (95% confidence interval: [Formula: see text] to 6.21). The mean Dice coefficient of pericardial fat voxels was [Formula: see text]. Our approach may potentially be applied in a clinical setting, allowing for accurate magnetic resonance imaging (MRI)-based PFV quantification without tedious manual tracing.
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Affiliation(s)
- Xiaowei Ding
- Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Department of Biomedical Sciences, 8700 Beverly Boulevard, Los Angeles, California 90048, United States
- University of California–Los Angeles, Computer Science Department, Computer Graphics & Vision Laboratory, 580 Portola Plaza, Los Angeles, California 90095, United States
| | - Jianing Pang
- Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Department of Biomedical Sciences, 8700 Beverly Boulevard, Los Angeles, California 90048, United States
| | - Zhou Ren
- University of California–Los Angeles, Computer Science Department, Computer Graphics & Vision Laboratory, 580 Portola Plaza, Los Angeles, California 90095, United States
| | - Mariana Diaz-Zamudio
- Cedars-Sinai Medical Center, Departments of Imaging and Medicine, 8700 Beverly Boulevard, Los Angeles, California 90048, United States
| | - Chenfanfu Jiang
- University of California–Los Angeles, Computer Science Department, Computer Graphics & Vision Laboratory, 580 Portola Plaza, Los Angeles, California 90095, United States
| | - Zhaoyang Fan
- Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Department of Biomedical Sciences, 8700 Beverly Boulevard, Los Angeles, California 90048, United States
| | - Daniel S. Berman
- Cedars-Sinai Medical Center, Departments of Imaging and Medicine, 8700 Beverly Boulevard, Los Angeles, California 90048, United States
- University of California–Los Angeles, Department of Medicine, David-Geffen School of Medicine, 10833 Le Conte Avenue, Los Angeles, California 90095, United States
| | - Debiao Li
- Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Department of Biomedical Sciences, 8700 Beverly Boulevard, Los Angeles, California 90048, United States
- University of California–Los Angeles, Department of Medicine, David-Geffen School of Medicine, 10833 Le Conte Avenue, Los Angeles, California 90095, United States
| | - Demetri Terzopoulos
- University of California–Los Angeles, Computer Science Department, Computer Graphics & Vision Laboratory, 580 Portola Plaza, Los Angeles, California 90095, United States
| | - Piotr J. Slomka
- Cedars-Sinai Medical Center, Departments of Imaging and Medicine, 8700 Beverly Boulevard, Los Angeles, California 90048, United States
- University of California–Los Angeles, Department of Medicine, David-Geffen School of Medicine, 10833 Le Conte Avenue, Los Angeles, California 90095, United States
| | - Damini Dey
- Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Department of Biomedical Sciences, 8700 Beverly Boulevard, Los Angeles, California 90048, United States
- University of California–Los Angeles, Department of Medicine, David-Geffen School of Medicine, 10833 Le Conte Avenue, Los Angeles, California 90095, United States
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15
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Yilmaz O, Saritas EU, Çukur T. Enhanced phase-sensitive SSFP reconstruction for fat-water separation in phased-array acquisitions. J Magn Reson Imaging 2015; 44:148-57. [PMID: 26696005 DOI: 10.1002/jmri.25138] [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: 10/08/2015] [Accepted: 12/08/2015] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To propose and assess a method to improve the reliability of phase-sensitive fat-water separation for phased-array balanced steady-state free precession (bSSFP) acquisitions. Phase-sensitive steady-state free precession (PS-SSFP) is an efficient fat-water separation technique that detects the phase difference between neighboring bands in the bSSFP magnetization profile. However, large spatial variations in the sensitivity profiles of phased-array coils can lead to noisy phase estimates away from the coil centers, compromising tissue classification. MATERIALS AND METHODS We first perform region-growing phase correction in individual coil images via unsupervised selection of a fat-voxel seed near the peak of each coil's sensitivity profile. We then use an optimal linear combination of phase-corrected images to segregate fat and water signals. The proposed method was demonstrated on noncontrast-enhanced SSFP angiograms of the thigh, lower leg, and foot acquired at 1.5T using an 8-channel coil. Individual coil PS-SSFP with a common seed selection for all coils, individual coil PS-SSFP with coil-wise seed selection, PS-SSFP after coil combination, and IDEAL reconstructions were also performed. Water images reconstructed via PS-SSFP methods were compared in terms of the level of fat suppression and the similarity to reference IDEAL images (signed-rank test). RESULTS While tissue misclassification was broadly evident across regular PS-SSFP images, the proposed method achieved significantly higher levels of fat suppression (P < 0.005) and increased similarity to reference IDEAL images (P < 0.005). CONCLUSION The proposed method enhances fat-water separation in phased-array acquisitions by producing improved phase estimates across the imaging volume. J. Magn. Reson. Imaging 2016;44:148-157.
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Affiliation(s)
- Ozgur Yilmaz
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey.,National Magnetic Resonance Research Center, Bilkent University, Ankara, Turkey
| | - Emine Ulku Saritas
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey.,National Magnetic Resonance Research Center, Bilkent University, Ankara, Turkey.,Neuroscience Program, Bilkent University, Ankara, Turkey
| | - Tolga Çukur
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey.,National Magnetic Resonance Research Center, Bilkent University, Ankara, Turkey.,Neuroscience Program, Bilkent University, Ankara, Turkey
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16
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Ribot EJ, Wecker D, Trotier AJ, Dallaudière B, Lefrançois W, Thiaudière E, Franconi JM, Miraux S. Water Selective Imaging and bSSFP Banding Artifact Correction in Humans and Small Animals at 3T and 7T, Respectively. PLoS One 2015; 10:e0139249. [PMID: 26426849 PMCID: PMC4591352 DOI: 10.1371/journal.pone.0139249] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 09/09/2015] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION The purpose of this paper is to develop an easy method to generate both fat signal and banding artifact free 3D balanced Steady State Free Precession (bSSFP) images at high magnetic field. METHODS In order to suppress fat signal and bSSFP banding artifacts, two or four images were acquired with the excitation frequency of the water-selective binomial radiofrequency pulse set On Resonance or shifted by a maximum of 3/4TR. Mice and human volunteers were imaged at 7 T and 3 T, respectively to perform whole-body and musculoskeletal imaging. "Sum-Of-Square" reconstruction was performed and combined or not with parallel imaging. RESULTS The frequency selectivity of 1-2-3-2-1 or 1-3-3-1 binomial pulses was preserved after (3/4TR) frequency shifting. Consequently, whole body small animal 3D imaging was performed at 7 T and enabled visualization of small structures within adipose tissue like lymph nodes. In parallel, this method allowed 3D musculoskeletal imaging in humans with high spatial resolution at 3 T. The combination with parallel imaging allowed the acquisition of knee images with ~500 μm resolution images in less than 2 min. In addition, ankles, full head coverage and legs of volunteers were imaged, demonstrating the possible application of the method also for large FOV. CONCLUSION In conclusion, this robust method can be applied in small animals and humans at high magnetic fields. The high SNR and tissue contrast obtained in short acquisition times allows to prescribe bSSFP sequence for several preclinical and clinical applications.
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Affiliation(s)
- Emeline J. Ribot
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, CNRS/University Bordeaux, Bordeaux, France
- * E-mail:
| | | | - Aurélien J. Trotier
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, CNRS/University Bordeaux, Bordeaux, France
| | - Benjamin Dallaudière
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, CNRS/University Bordeaux, Bordeaux, France
| | - William Lefrançois
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, CNRS/University Bordeaux, Bordeaux, France
| | - Eric Thiaudière
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, CNRS/University Bordeaux, Bordeaux, France
| | - Jean-Michel Franconi
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, CNRS/University Bordeaux, Bordeaux, France
| | - Sylvain Miraux
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, CNRS/University Bordeaux, Bordeaux, France
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17
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Kellman P, Bandettini WP, Mancini C, Hammer-Hansen S, Hansen MS, Arai AE. Characterization of myocardial T1-mapping bias caused by intramyocardial fat in inversion recovery and saturation recovery techniques. J Cardiovasc Magn Reson 2015; 17:33. [PMID: 25958014 PMCID: PMC4425910 DOI: 10.1186/s12968-015-0136-y] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 04/24/2015] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Quantitative measurement of T1 in the myocardium may be used to detect both focal and diffuse disease processes such as interstitial fibrosis or edema. A partial volume problem exists when a voxel in the myocardium also contains fat. Partial volume with fat occurs at tissue boundaries or within the myocardium in the case of lipomatous metaplasia of replacement fibrosis, which is commonly seen in chronic myocardial infarction. The presence of fat leads to a bias in T1 measurement. The mechanism for this artifact for widely used T1 mapping protocols using balanced steady state free precession readout and the dependence on off-resonance frequency are described in this paper. METHODS Simulations were performed to illustrate the behavior of mono-exponential fitting to bi-exponential mixtures of myocardium and fat with varying fat fractions. Both inversion recovery and saturation recovery imaging protocols using balanced steady state free precession are considered. In-vivo imaging with T1-mapping, water/fat separated imaging, and late enhancement imaging was performed on subjects with chronic myocardial infarction. RESULTS In n = 17 subjects with chronic myocardial infarction, lipomatous metaplasia is evident in 8 patients (47%). Fat fractions as low as 5% caused approximately 6% T1 elevation for the out-of-phase condition, and approximately 5% reduction of T1 for the in-phase condition. T1 bias in excess of 1000 ms was observed in lipomatous metaplasia with fat fraction of 38% in close agreement with simulation of the specific imaging protocols. CONCLUSIONS Measurement of the myocardial T1 by widely used balanced steady state free precession mapping methods is subject to bias when there is a mixture of water and fat in the myocardium. Intramyocardial fat is frequently present in myocardial scar tissue due lipomatous metaplasia, a process affecting myocardial infarction and some non-ischemic cardiomyopathies. In cases of lipomatous metaplasia, the T1 biases will be additive or subtractive depending on whether the center frequency corresponds to the myocardium and fat being in-phase or out-of-phase, respectively. It is important to understand this mechanism, which may otherwise lead to erroneous interpretation.
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Affiliation(s)
- Peter Kellman
- National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD, 20892, USA.
| | - W Patricia Bandettini
- National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD, 20892, USA.
| | - Christine Mancini
- National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD, 20892, USA.
| | - Sophia Hammer-Hansen
- National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD, 20892, USA.
| | - Michael S Hansen
- National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD, 20892, USA.
| | - Andrew E Arai
- National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD, 20892, USA.
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18
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Feng X, Salerno M, Kramer CM, Meyer CH. Non-Cartesian balanced steady-state free precession pulse sequences for real-time cardiac MRI. Magn Reson Med 2015; 75:1546-55. [PMID: 25960254 DOI: 10.1002/mrm.25738] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 02/19/2015] [Accepted: 03/26/2015] [Indexed: 11/09/2022]
Abstract
PURPOSE To develop a new spiral-in/out balanced steady-state free precession (bSSFP) pulse sequence for real-time cardiac MRI and compare it with radial and spiral-out techniques. METHODS Non-Cartesian sampling strategies are efficient and robust to motion and thus have important advantages for real-time bSSFP cine imaging. This study describes a new symmetric spiral-in/out sequence with intrinsic gradient moment compensation and SSFP refocusing at TE = TR/2. In vivo real-time cardiac imaging studies were performed to compare radial, spiral-out, and spiral-in/out bSSFP pulse sequences. Furthermore, phase-based fat/water separation taking advantage of the refocusing mechanism of the spiral-in/out bSSFP sequence was also studied. RESULTS The image quality of the spiral-out and spiral-in/out bSSFP sequences was improved with off-resonance and k-space trajectory correction. The spiral-in/out bSSFP sequence had the highest signal-to-noise ratio (SNR), contrast-to-noise ratio, and image quality ratings, with spiral-out bSSFP sequence second in each category and the radial bSSFP sequence third. The spiral-in/out bSSFP sequence provides separated fat and water images with no additional scan time. CONCLUSIONS In this study, a new spiral-in/out bSSFP sequence was developed and tested. The superiority of spiral bSSFP sequences over the radial bSSFP sequence in terms of SNR and reduced artifacts was demonstrated in real-time MRI of cardiac function without image acceleration.
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Affiliation(s)
- Xue Feng
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Michael Salerno
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA.,Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, USA.,Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Christopher M Kramer
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, USA.,Department of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Craig H Meyer
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA.,Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, USA
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19
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Henze Bancroft LC, Strigel RM, Hernando D, Johnson KM, Kelcz F, Kijowski R, Block WF. Utilization of a balanced steady state free precession signal model for improved fat/water decomposition. Magn Reson Med 2015; 75:1269-77. [PMID: 25946145 DOI: 10.1002/mrm.25728] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 03/10/2015] [Accepted: 03/20/2015] [Indexed: 12/21/2022]
Abstract
PURPOSE Chemical shift based fat/water decomposition methods such as IDEAL are frequently used in challenging imaging environments with large B0 inhomogeneity. However, they do not account for the signal modulations introduced by a balanced steady state free precession (bSSFP) acquisition. Here we demonstrate improved performance when the bSSFP frequency response is properly incorporated into the multipeak spectral fat model used in the decomposition process. THEORY AND METHODS Balanced SSFP allows for rapid imaging but also introduces a characteristic frequency response featuring periodic nulls and pass bands. Fat spectral components in adjacent pass bands will experience bulk phase offsets and magnitude modulations that change the expected constructive and destructive interference between the fat spectral components. A bSSFP signal model was incorporated into the fat/water decomposition process and used to generate images of a fat phantom, and bilateral breast and knee images in four normal volunteers at 1.5 Tesla. RESULTS Incorporation of the bSSFP signal model into the decomposition process improved the performance of the fat/water decomposition. CONCLUSION Incorporation of this model allows rapid bSSFP imaging sequences to use robust fat/water decomposition methods such as IDEAL. While only one set of imaging parameters were presented, the method is compatible with any field strength or repetition time.
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Affiliation(s)
- Leah C Henze Bancroft
- University of Wisconsin-Madison, Department of Medical Physics, Wisconsin Institutes for Medical Research, Madison, Wisconsin, USA
| | - Roberta M Strigel
- University of Wisconsin-Madison, Department of Medical Physics, Wisconsin Institutes for Medical Research, Madison, Wisconsin, USA.,University of Wisconsin School of Medicine and Public health, Department of Radiology, Madison, Wisconsin, USA.,University of Wisconsin Carbone Cancer Center, Wisconsin Institutes for Medical Research, Madison, Wisconsin, USA
| | - Diego Hernando
- University of Wisconsin-Madison, Department of Radiology, Wisconsin Institutes for Medical Research, Madison, Wisconsin, USA
| | - Kevin M Johnson
- University of Wisconsin-Madison, Department of Medical Physics, Wisconsin Institutes for Medical Research, Madison, Wisconsin, USA
| | - Frederick Kelcz
- University of Wisconsin School of Medicine and Public health, Department of Radiology, Madison, Wisconsin, USA
| | - Richard Kijowski
- University of Wisconsin School of Medicine and Public health, Department of Radiology, Madison, Wisconsin, USA
| | - Walter F Block
- University of Wisconsin-Madison, Department of Medical Physics, Wisconsin Institutes for Medical Research, Madison, Wisconsin, USA.,University of Wisconsin-Madison, Department of Radiology, Wisconsin Institutes for Medical Research, Madison, Wisconsin, USA.,University of Wisconsin-Madison, Department of Biomedical Engineering, Wisconsin Institutes for Medical Research, Madison, Wisconsin
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20
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Çukur T. Spectrally selective imaging with wideband balanced steady-state free precession MRI. Magn Reson Med 2015; 75:1132-41. [PMID: 25846631 DOI: 10.1002/mrm.25700] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 01/26/2015] [Accepted: 02/25/2015] [Indexed: 11/10/2022]
Abstract
PURPOSE Unwanted, bright fat signals in balanced steady-state free precession sequences are commonly suppressed using spectral shaping. Here, a new spectral-shaping method is proposed to significantly improve the uniformity of stopband suppression without compromising the level of passband signals. METHODS The proposed method combines binomial-pattern excitation pulses with a wideband balanced steady-state free precession sequence kernel. It thereby increases the frequency separation between the centers of pass and stopbands by π radians, enabling improved water-fat contrast. Simulations were performed to find the optimal flip angles and subpulse spacing for the binomial pulses that maximize contrast and signal efficiency. RESULTS Comparisons with a conventional binomial balanced steady-state free precession sequence were performed in simulations as well as phantom and in vivo experiments at 1.5 T and 3 T. Enhanced fat suppression is demonstrated in vivo with an average improvement of 58% in blood-fat and 68% in muscle-fat contrast (P < 0.001, Wilcoxon signed-rank test). CONCLUSION The proposed binomial wideband balanced steady-state free precession method is a promising candidate for spectrally selective imaging with enhanced reliability against field inhomogeneities.
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Affiliation(s)
- Tolga Çukur
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey.,National Magnetic Resonance Research Center, Bilkent University, Ankara, Turkey
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21
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Edelman RR, Giri S, Murphy IG, Flanagan O, Speier P, Koktzoglou I. Ungated radial quiescent-inflow single-shot (UnQISS) magnetic resonance angiography using optimized azimuthal equidistant projections. Magn Reson Med 2014; 72:1522-9. [PMID: 25257379 DOI: 10.1002/mrm.25477] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 08/22/2014] [Accepted: 09/04/2014] [Indexed: 11/07/2022]
Abstract
PURPOSE We hypothesized that non-contrast-enhanced MR angiography (NEMRA) could be performed without cardiac gating by using a variant of the quiescent-inflow single-shot (QISS) technique. METHODS Ungated QISS (UnQISS) MRA was evaluated in eight patients with peripheral arterial disease at 1.5T. The radial acquisition used optimized azimuthal equidistant projections, a long quiescent inflow time (1200 ms) to ensure replenishment of saturated in-plane spins irrespective of the cardiac phase, and a lengthy readout (1200 ms) so that a complete cardiac cycle was sampled for each slice. Venous and background tissue suppression was obtained using frequency-offset-corrected inversion radiofrequency pulses. RESULTS Scan time for UnQISS was 15.4 min for an eight-station whole-leg acquisition. The appearance of UnQISS MRA acquired using the body coil was comparable to electrocardiographic-gated QISS MRA using phased array coils. A small radial view angle increment minimized eddy current-related artifacts, whereas image quality was inferior with a golden view angle radial increment or Cartesian trajectory. In patient studies, ≥50% stenoses were consistently detected. CONCLUSION Using UnQISS, peripheral NEMRA can be performed without the need for cardiac gating. The use of fixed imaging parameters and body coil for signal reception further simplifies the scan procedure.
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Affiliation(s)
- Robert R Edelman
- NorthShore University HealthSystem, Evanston, Illinois, USA; Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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22
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Quist B, Hargreaves BA, Daniel BL, Saranathan M. Balanced SSFP Dixon imaging with banding-artifact reduction at 3 Tesla. Magn Reson Med 2014; 74:706-15. [PMID: 25227766 DOI: 10.1002/mrm.25449] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 08/20/2014] [Accepted: 08/21/2014] [Indexed: 01/10/2023]
Abstract
PURPOSE To develop a three-dimensional (3D) balanced steady-state free-precession (bSSFP) two-point Dixon method with banding-artifact suppression to offer robust high-resolution 3D bright-fluid imaging. METHODS A complex sum reconstruction that combines phase-cycled bSSFP images acquired at specific echo times for robust fat/water separation without banding was investigated and compared with a magnitude-based method. Bloch simulations using both single-peak and multiple-peak fat models were performed to predict the performance of these methods for a wide range of echo times and repetition times. The quality and degree of fat/water separation was evaluated in both simulations and using in vivo imaging. RESULTS Simulations predicted that both effective banding-artifact suppression and substantial improvements in fat/water separation are possible at echo times that are different from conventional echo times, enabling improved spatial resolution. Comparisons between various echo times and repetition times in vivo validated the improved fat/water separation and effective banding-artifact removal predicted by the simulations. CONCLUSION The proposed complex sum Dixon 3D bSSFP method is able to effectively separate fat and water at different sets of echo times, while removing banding-artifacts, providing a fast, high-resolution, T2 -like sequence without blurring.
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Affiliation(s)
- Brady Quist
- Department of Radiology, Stanford University, Stanford, California, USA.,Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | | | - Bruce L Daniel
- Department of Radiology, Stanford University, Stanford, California, USA
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23
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Koktzoglou I, Mistretta CA, Giri S, Dunkle EE, Amin P, Edelman RR. Simultaneous static and cine nonenhanced MR angiography using radial sampling and highly constrained back projection reconstruction. Magn Reson Med 2013; 72:1079-86. [PMID: 24407879 DOI: 10.1002/mrm.25008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Revised: 09/12/2013] [Accepted: 09/28/2013] [Indexed: 11/06/2022]
Abstract
PURPOSE To describe a pulse sequence for simultaneous static and cine nonenhanced magnetic resonance angiography (NEMRA) of the peripheral arteries. METHODS The peripheral arteries of 10 volunteers and 6 patients with peripheral arterial disease (PAD) were imaged with the proposed cine NEMRA sequence on a 1.5 Tesla (T) system. The impact of multi-shot imaging and highly constrained back projection (HYPR) reconstruction was examined. The propagation rate of signal along the length of the arterial tree in the cine nonenhanced MR angiograms was quantified. RESULTS The cine NEMRA sequence simultaneously provided a static MR angiogram showing vascular anatomy as well as a cine display of arterial pulse wave propagation along the entire length of the peripheral arteries. Multi-shot cine NEMRA improved temporal resolution and reduced image artifacts. HYPR reconstruction improved image quality when temporal reconstruction footprints shorter than 100 ms were used (P < 0.001). Pulse wave propagation within the arterial tree as displayed by cine NEMRA was slower in patients with PAD than in volunteers. CONCLUSION Simultaneous static and cine NEMRA of the peripheral arteries is feasible. Multi-shot acquisition and HYPR reconstruction can be used to improve arterial conspicuity and temporal resolution.
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Affiliation(s)
- Ioannis Koktzoglou
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA; The University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
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24
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Aquaro GD, Todiere G, Strata E, Barison A, Di Bella G, Lombardi M. Usefulness of India ink artifact in steady-state free precession pulse sequences for detection and quantification of intramyocardial fat. J Magn Reson Imaging 2013; 40:126-32. [PMID: 24127127 DOI: 10.1002/jmri.24335] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 07/10/2013] [Indexed: 11/12/2022] Open
Abstract
PURPOSE In steady state free precession (SSFP) images acquired with a repetition time/echo time (TR/TE) ≈ 2, fat is surrounded by a black boundary, called "India Ink" artifact. Indian Ink artifact may improve detection of intramyocardial fat. Aims of this study were: (i) to assess the accuracy of SSFP technique for the detection of fat metaplasia in remote myocardial infarction (RMI); (ii) to evaluate the inter- and intraobserver reproducibility for the quantification of intramyocardial fat using SSFP and fast spin echo/short TI inversion recovery (FSE/STIR) techniques. MATERIALS AND METHODS A total of 200 patients (age 64 ± 10 years) with RMI (>1000 days) underwent MRI using a 1.5 Tesla (T) scanner. SSFP images (with a TR/TE ≈2), FSE and STIR images were acquired in short and long axis views. Fat was detected in FSE/STIR and SSFP images and its extent manually measured . The inter- and intraobserver agreement for the quantification of fat metaplasia using both the SSFP image and the FSE images was evaluated. RESULTS Left ventricle intramyocardial fat was detected in SSFP images of 95 patients (47.5%) and in FSE/STIR images of 84 patients (42%). A very good agreement was found using the SSFP technique between investigators. CONCLUSION SSFP sequence with TR/TE=2 is a valuable technique for identifying and quantifying the presence of fat tissue within the left ventricle myocardium in RMI.
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25
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Goldfarb JW, Arnold-Anteraper S. Water-fat separation imaging of the heart with standard magnetic resonance bSSFP CINE imaging. Magn Reson Med 2013; 71:2096-104. [PMID: 23904254 DOI: 10.1002/mrm.24879] [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: 04/17/2013] [Revised: 06/18/2013] [Accepted: 06/18/2013] [Indexed: 12/19/2022]
Abstract
PURPOSE To study balanced steady-state free precession CINE phase-sensitive water-fat separation imaging in four cardiac imaging planes to determine the necessary phase correction and image artifacts particular to this technique. METHODS Ten healthy volunteers and two subjects with known heart pathologies were studied with standard balanced steady-state free precession CINE imaging. Water-only and fat-only images were calculated using sign detection of the real part of the complex image after phase correction with constant and linear terms. Phase correction values were determined using both manual and automated methods. Differences in phase correction values between imaging planes, cardiac phases, coil elements, automated image reconstruction parameters as well as artifact scores between the automated and manual methods were studied with statistical tests. RESULTS Water-fat separation performed well in the heart after constant and linear phase correction. Both constant (p = 0.8) and linear x (p = 1) and y (p = 1) phase correction values did not vary significantly across cardiac phases, but varied significantly among the coils (p < 0.001) and imaging planes (p < 0.001). False water-fat separation artifacts were most frequent in the chest/back and also were present at the mitral and aortic valves. CONCLUSION Constant and linear phase correction is necessary to provide consistent results in standard imaging planes using a balanced steady-state free precession water-fat separation postprocessing algorithm applied to standard cardiac CINE imaging.
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Affiliation(s)
- James W Goldfarb
- Department of Research and Education, Saint Francis Hospital, Roslyn, New York, USA; Program in Biomedical Engineering, SUNY Stony Brook, Stony Brook, New York, USA
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Edelman RR, Giri S, Dunkle E, Galizia M, Amin P, Koktzoglou I. Quiescent-inflow single-shot magnetic resonance angiography using a highly undersampled radial k-space trajectory. Magn Reson Med 2013; 70:1662-8. [PMID: 23348595 DOI: 10.1002/mrm.24596] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 11/01/2012] [Accepted: 11/26/2012] [Indexed: 11/09/2022]
Abstract
PURPOSE We hypothesized that high undersampling factors could be used in conjunction with radial quiescent-inflow single-shot magnetic resonance angiography (MRA) to accelerate the data acquisition and enable multislice acquisitions. METHODS Seven subjects were imaged on a 1.5 T MRI system. For multislice quiescent-inflow single-shot MRA, the venous saturation radiofrequency pulse, in-plane saturation radiofrequency pulse, and quiescent interval were applied only once before the first slice. RESULTS The mean (standard deviation) measurements for the intra-arterial signal-to-noise ratio were as follows: Cartesian 1 slice-29.3 (5.5); radial 1 slice, 92 views-22.3 (3.6); radial 1 slice, 46 views-18.5 (2.0); radial 2 slices, 46 views-18.3 (3.2); and radial 3 slices, 32 views-21.7 (3.9), normalized for pixel size to 15.8. Horizontal striping was present with multislice radial quiescent-inflow single-shot MRA (especially with the three-slice acquisition) due to variable T1 relaxation between the concurrently acquired slices, but the image quality remained diagnostic. Vascular pathology in patients with peripheral arterial disease was well shown by all techniques. CONCLUSION Very high undersampling factors in excess of 18 have been demonstrated for nonenhanced MRA using a radial quiescent-inflow single-shot technique, enabling the acquisition of two to three slices per cardiac cycle. Scan time for a complete peripheral MRA could be shortened to 2 min or less.
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Affiliation(s)
- R R Edelman
- NorthShore University HealthSystem, Evanston, Illinois, USA; Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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Hargreaves BA. Rapid gradient-echo imaging. J Magn Reson Imaging 2012; 36:1300-13. [PMID: 23097185 DOI: 10.1002/jmri.23742] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 05/24/2012] [Indexed: 11/07/2022] Open
Abstract
Gradient-echo sequences are widely used in magnetic resonance imaging (MRI) for numerous applications ranging from angiography to perfusion to functional MRI. Compared with spin-echo techniques, the very short repetition times of gradient-echo methods enable very rapid 2D and 3D imaging, but also lead to complicated "steady states." Signal and contrast behavior can be described graphically and mathematically, and depends strongly on the type of spoiling: fully balanced (no spoiling), gradient spoiling, or radiofrequency (RF)-spoiling. These spoiling options trade off between high signal and pure T(1) contrast, while the flip angle also affects image contrast in all cases, both of which can be demonstrated theoretically and in image examples. As with spin-echo sequences, magnetization preparation can be added to gradient-echo sequences to alter image contrast. Gradient-echo sequences are widely used for numerous applications such as 3D perfusion imaging, functional MRI, cardiac imaging, and MR angiography.
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Affiliation(s)
- Brian A Hargreaves
- Department of Radiology, Stanford University, Stanford, California, USA.
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von Morze C, Sukumar S, Reed GD, Larson PEZ, Bok RA, Kurhanewicz J, Vigneron DB. Frequency-specific SSFP for hyperpolarized ¹³C metabolic imaging at 14.1 T. Magn Reson Imaging 2012; 31:163-70. [PMID: 22898680 DOI: 10.1016/j.mri.2012.06.037] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 06/22/2012] [Accepted: 06/28/2012] [Indexed: 11/18/2022]
Abstract
Metabolic imaging of hyperpolarized [1-(13)C] pyruvate co-polarized with [(13)C]urea by dynamic nuclear polarization with rapid dissolution is a promising new method for assessing tumor metabolism and perfusion simultaneously in vivo. Novel pulse sequences are required to enable dynamic imaging of multiple (13)C spectral lines with high spatiotemporal resolution. The goal of this study was to investigate a new frequency-specific approach for rapid metabolic imaging of multiple (13)C resonances using the spectral selectivity of steady-state free precession pulse (SSFP) trains. Methods developed in simulations were implemented in a dynamic frequency-cycled balanced SSFP pulse sequence on a 14.1-T animal magnetic resonance imaging scanner. This acquisition was tested in thermal and hyperpolarized phantom imaging studies and in a transgenic mouse with prostate cancer.
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Affiliation(s)
- Cornelius von Morze
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA.
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Hu HH, Börnert P, Hernando D, Kellman P, Ma J, Reeder S, Sirlin C. ISMRM workshop on fat-water separation: insights, applications and progress in MRI. Magn Reson Med 2012; 68:378-88. [PMID: 22693111 PMCID: PMC3575097 DOI: 10.1002/mrm.24369] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 05/14/2012] [Accepted: 05/16/2012] [Indexed: 12/12/2022]
Abstract
Approximately 130 attendees convened on February 19-22, 2012 for the first ISMRM-sponsored workshop on water-fat imaging. The motivation to host this meeting was driven by the increasing number of research publications on this topic over the past decade. The scientific program included an historical perspective and a discussion of the clinical relevance of water-fat MRI, a technical description of multiecho pulse sequences, a review of data acquisition and reconstruction algorithms, a summary of the confounding factors that influence quantitative fat measurements and the importance of MRI-based biomarkers, a description of applications in the heart, liver, pancreas, abdomen, spine, pelvis, and muscles, an overview of the implications of fat in diabetes and obesity, a discussion on MR spectroscopy, a review of childhood obesity, the efficacy of lifestyle interventional studies, and the role of brown adipose tissue, and an outlook on federal funding opportunities from the National Institutes of Health.
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Affiliation(s)
- Houchun Harry Hu
- Departments of Radiology and Electrical Engineering, Children's Hospital Los Angeles, University of Southern California, Los Angeles, California 90027, USA.
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Gonçalves SI, Ziech MLW, Lamerichs R, Stoker J, Nederveen AJ. Optimization of alternating TR-SSFP for fat-suppression in abdominal images at 3T. Magn Reson Med 2011; 67:595-600. [DOI: 10.1002/mrm.23215] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 08/02/2011] [Accepted: 08/22/2011] [Indexed: 12/12/2022]
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Quist B, Hargreaves BA, Cukur T, Morrell GR, Gold GE, Bangerter NK. Simultaneous fat suppression and band reduction with large-angle multiple-acquisition balanced steady-state free precession. Magn Reson Med 2011; 67:1004-12. [PMID: 22038883 DOI: 10.1002/mrm.23076] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 05/01/2011] [Accepted: 06/08/2011] [Indexed: 01/13/2023]
Abstract
Balanced steady-state free precession (bSSFP) MRI is a rapid and signal-to-noise ratio-efficient imaging method, but suffers from characteristic bands of signal loss in regions of large field inhomogeneity. Several methods have been developed to reduce the severity of these banding artifacts, typically involving the acquisition of multiple bSSFP datasets (and the accompanying increase in scan time). Fat suppression with bSSFP is also challenging; most existing methods require an additional increase in scan time, and some are incompatible with bSSFP band-reduction techniques. This work was motivated by the need for both robust fat suppression and band reduction in the presence of field inhomogeneity when using bSSFP for flow-independent peripheral angiography. The large flip angles used in this application to improve vessel conspicuity and contrast lead to specific absorption rate considerations, longer repetition times, and increased severity of banding artifacts. In this work, a novel method that simultaneously suppresses fat and reduces bSSFP banding artifact with the acquisition of only two phase-cycled bSSFP datasets is presented. A weighted sum of the two bSSFP acquisitions is taken on a voxel-by-voxel basis, effectively synthesizing an off-resonance profile at each voxel that puts fat in the stop band while keeping water in the pass band. The technique exploits the near-sinusoidal shape of the bSSFP off-resonance spectrum for many tissues at large (>50°) flip angles.
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Affiliation(s)
- Brady Quist
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT, USA
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32
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Bangerter NK, Cukur T, Hargreaves BA, Hu BS, Brittain JH, Park D, Gold GE, Nishimura DG. Three-dimensional fluid-suppressed T2-prep flow-independent peripheral angiography using balanced SSFP. Magn Reson Imaging 2011; 29:1119-24. [PMID: 21705166 DOI: 10.1016/j.mri.2011.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2010] [Revised: 03/29/2011] [Accepted: 04/04/2011] [Indexed: 10/18/2022]
Abstract
Accurate depiction of the vessels of the lower leg, foot or hand benefits from suppression of bright MR signal from lipid (such as bone marrow) and long-T1 fluid (such as synovial fluid and edema). Signal independence of blood flow velocities, good arterial/muscle contrast and arterial/venous separation are also desirable. The high SNR, short scan times and flow properties of balanced steady-state free precession (SSFP) make it an excellent candidate for flow-independent angiography. In this work, a new magnetization-prepared 3D SSFP sequence for flow-independent peripheral angiography is presented. The technique combines a number of component techniques (phase-sensitive fat detection, inversion recovery, T2-preparation and square-spiral phase-encode ordering) to achieve high-contrast peripheral angiograms at only a modest scan time penalty over simple 3D SSFP. The technique is described in detail, a parameter optimization performed and preliminary results presented achieving high contrast and 1-mm isotropic resolution in a normal foot.
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Affiliation(s)
- Neal K Bangerter
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA.
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Aquaro GD, Nucifora G, Pederzoli L, Strata E, De Marchi D, Todiere G, Andrea B, Pingitore A, Lombardi M. Fat in left ventricular myocardium assessed by steady-state free precession pulse sequences. Int J Cardiovasc Imaging 2011; 28:813-21. [DOI: 10.1007/s10554-011-9886-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 05/03/2011] [Indexed: 10/18/2022]
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Kimura F, Matsuo Y, Nakajima T, Nishikawa T, Kawamura S, Sannohe S, Hagiwara N, Sakai F. Myocardial fat at cardiac imaging: how can we differentiate pathologic from physiologic fatty infiltration? Radiographics 2011; 30:1587-602. [PMID: 21071377 DOI: 10.1148/rg.306105519] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Myocardial fat is often seen at cardiac computed tomography (CT) and magnetic resonance (MR) imaging of healthy adults and patients with myocardial diseases. Physiologic myocardial fat develops with aging and is commonly seen at CT in the anterolateral right ventricular (RV) free wall and RV outflow tract with normal or thickened RV myocardium and a normal-sized RV in elderly patients. Pathologic conditions with myocardial fat include healed myocardial infarction (MI); arrhythmogenic RV cardiomyopathy or dysplasia (ARVC); and others, such as cardiac lipoma, lipomatous hypertrophy of the interatrial septum, tuberous sclerosis complex, dilated cardiomyopathy, and cardiomyopathy with muscular dystrophy. In patients with healed MI, CT and MR imaging show fat in left ventricular myocardium that is of normal thickness or thin and follows the distribution of the coronary artery; CT often depicts fat in mostly subendocardial regions. In patients with ARVC, characteristic CT and MR imaging findings include a thin RV outflow tract and free wall caused by subepicardial fatty infiltration; fat in the RV moderator band, trabeculae, and ventricular septum; and RV enlargement and wall motion abnormality. Recognition of patient age, characteristic locations of myocardial fat, myocardial thickness, and ventricular size helps in differentiating physiologic and pathologic myocardial fat at cardiac imaging; findings of wall motion abnormality and late gadolinium enhancement at MR imaging help narrow the diagnosis.
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Affiliation(s)
- Fumiko Kimura
- Department of Diagnostic Radiology, Saitama Medical University International Medical Center, Hidaka-shi, Saitama, Japan.
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Ababneh R, Yuan J, Madore B. Fat-water separation in dynamic objects using an UNFOLD-like temporal processing. J Magn Reson Imaging 2011; 32:962-70. [PMID: 20882627 DOI: 10.1002/jmri.22321] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To separate fat and water signals in dynamic imaging. Because important features may be embedded in fat, and because fat may take part in disease processes, separating fat and water signals may be of great importance in a number of clinical applications. This work aims to achieve such separation at nearly no loss in temporal resolution compared to usual, nonseparated acquisitions. In contrast, the well-known 3-point Dixon method may cause as much as a 3-fold reduction in temporal resolution. MATERIALS AND METHODS The proposed approach involves modulating the echo time TE from frame to frame, to force fat signals to behave in a conspicuous manner through time, so they can be readily identified and separated from water signals. The strategy is inspired from the "unaliasing by Fourier encoding the overlaps in the temporal direction" (UNFOLD) method, although UNFOLD involves changes in the sampling function rather than TE, and aims at suppressing aliased material rather than fat. RESULTS The method was implemented at 1.5 T and 3 T, on cardiac cine and multiframe steady-state free precession sequences. In addition to phantom results, in vivo results from volunteers are presented. CONCLUSION Good separation of fat and water signals was achieved in all cases.
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Affiliation(s)
- Riad Ababneh
- Physics Department, Yarmouk University, Irbid, Jordan
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36
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Yuan J, Madore B, Panych LP. Fat-water selective excitation in balanced steady-state free precession using short spatial-spectral RF pulses. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 208:219-224. [PMID: 21134770 PMCID: PMC3034310 DOI: 10.1016/j.jmr.2010.11.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 11/09/2010] [Accepted: 11/09/2010] [Indexed: 05/30/2023]
Abstract
Fat suppression is important but challenging in balanced steady-state free precession (bSSFP) acquisitions, for a number of clinical applications. In the present work, the practicality of performing fat-water selective excitations using spatial-spectral (SPSP) RF pulses in bSSFP sequence is examined. With careful pulse design, the overall duration of these SPSP pulses was kept short to minimize detrimental effects on TR, scan time and banding artifact content. Fat-water selective excitation using SPSP pulses was demonstrated in both phantom and human bSSFP imaging at 3T, and compared to results obtained using a two-point Dixon method. The sequence with SPSP pulses performed better than the two-point Dixon method, in terms of scan time and suppression performance. Overall, it is concluded here that SPSP RF pulses do represent a viable option for fat-suppressed bSSFP imaging.
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Affiliation(s)
- Jing Yuan
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
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37
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Radlbauer R, Salomonowitz E, van der Riet W, Stadlbauer A. Triggered non-contrast enhanced MR angiography of peripheral arteries: optimization of systolic and diastolic time delays for electrocardiographic triggering. Eur J Radiol 2010; 80:331-5. [PMID: 21030171 DOI: 10.1016/j.ejrad.2010.09.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Accepted: 09/23/2010] [Indexed: 11/16/2022]
Abstract
The purpose of this study was to determine the optimal systolic and diastolic time delays for electrocardiographic triggering of a non-contrast media enhanced MR angiography using a 3-dimensional fast spin echo sequence in patients suffering from peripheral arterial disease. 12 patients with suspected peripheral arterial disease were examined on a 1.5 T Philips Achieva MR scanner. A cardiac-triggered Volumetric Isotropic T2-weighted fast spin echo sequence was performed using variable trigger delays for systolic and diastolic phase. The signal in the popliteal arteries and anterior tibial arteries of the systolic and diastolic images was measured and optimal delay times for systolic and diastolic phase were determined. Minimum signal to noise ratio (SNR) appears at the time difference ΔT=-21 ms on systolic images of the popliteal arteries. In the anterior tibial arteries the minimum SNR is significantly higher and appears at the time difference ΔT=-14 ms. Diastolic delay times must be chosen as long or as short as possible depending on heart rate. In peripheral vessels triggered non-contrast MR angiography can yield results which are comparable with contrast enhanced MRA techniques. It is crucial to optimize timing parameters.
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Affiliation(s)
- Rudolf Radlbauer
- MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, 3100 St. Poelten, Austria.
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Goldfarb JW. Magnetic resonance separation imaging using a divided inversion recovery technique (DIRT). Magn Reson Med 2010; 63:1007-14. [PMID: 20373401 DOI: 10.1002/mrm.22281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The divided inversion recovery technique is an MRI separation method based on tissue T(1) relaxation differences. When tissue T(1) relaxation times are longer than the time between inversion pulses in a segmented inversion recovery pulse sequence, longitudinal magnetization does not pass through the null point. Prior to additional inversion pulses, longitudinal magnetization may have an opposite polarity. Spatial displacement of tissues in inversion recovery balanced steady-state free-precession imaging has been shown to be due to this magnetization phase change resulting from incomplete magnetization recovery. In this paper, it is shown how this phase change can be used to provide image separation. A pulse sequence parameter, the time between inversion pulses (T180), can be adjusted to provide water-fat or fluid separation. Example water-fat and fluid separation images of the head, heart, and abdomen are presented. The water-fat separation performance was investigated by comparing image intensities in short-axis divided inversion recovery technique images of the heart. Fat, blood, and fluid signal was suppressed to the background noise level. Additionally, the separation performance was not affected by main magnetic field inhomogeneities.
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Affiliation(s)
- James W Goldfarb
- Department of Research and Education, Saint Francis Hospital, Roslyn, NewYork, USA.
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MacKenzie JD, Vasanawala SS. State-of-the-art in pediatric body and musculoskeletal magnetic resonance imaging. Semin Ultrasound CT MR 2010; 31:86-99. [PMID: 20304318 DOI: 10.1053/j.sult.2010.01.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Pediatric body and musculoskeletal MRI has seen tremendous advances over the past few years. These advances have enabled high-quality imaging in even the smallest children and expanded the range of clinical problems amenable to MRI. In this review, we highlight some advances: transition to 3 Tesla, parallel imaging, motion compensation, and new contrast agents. Given the increasing saliency of concerns regarding ionizing radiation from computed tomography, these advances could not be more welcome.
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Affiliation(s)
- John D MacKenzie
- Division of Pediatric Radiology, Lucile Packard Children's Hospital, Stanford University, Palo Alto, CA 94304, USA
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Klaers J, Jashnani Y, Jung Y, Brodsky E, Jacobson J, Kijowski R, Block WF. Dual half-echo phase correction for implementation of 3D radial SSFP at 3.0 T. Magn Reson Med 2010; 63:282-9. [PMID: 20099322 DOI: 10.1002/mrm.22284] [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]
Abstract
Fat/water separation methods such as fluctuating equilibrium magnetic resonance and linear combination steady-state free precession have not yet been successfully implemented at 3.0 T due to extreme limitations on the time available for spatial encoding with the increase in magnetic field strength. We present a method to utilize a three-dimensional radial sequence combined with linear combination steady-state free precession at 3.0 T to take advantage of the increased signal levels over 1.5 T and demonstrate high spatial resolution compared to Cartesian techniques. We exploit information from the two half-echoes within each pulse repetition time to correct the accumulated phase on a point-by-point basis, thereby fully aligning the phase of both half-echoes. The correction provides reduced sensitivity to static field (B(0)) inhomogeneity and robust fat/water separation. Resultant images in the knee joint demonstrate the necessity of such a correction, as well as the increased isotropic spatial resolution attainable at 3.0 T. Results of a clinical study comparing this sequence to conventional joint imaging sequences are included.
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Affiliation(s)
- Jessica Klaers
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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Miller KL, Smith SM, Jezzard P. Asymmetries of the balanced SSFP profile. Part II: white matter. Magn Reson Med 2010; 63:396-406. [PMID: 20099329 DOI: 10.1002/mrm.22249] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The signal profile measured in balanced steady-state free precession has been shown to exhibit tissue-dependent asymmetries that were hypothesized to relate to properties of the tissue microenvironment. It was proposed that balanced steady-state free precession asymmetry may reflect subtle features of the frequency distribution in tissue. The present work investigates the large balanced steady-state free precession asymmetries observed in white matter. First, maps quantifying the asymmetry are presented, which demonstrate considerable heterogeneity within white matter, with some tracts exhibiting significant asymmetry and others having a nearly symmetric profile. These maps are compared with a diffusion-tensor atlas and indicate that the highest asymmetry is found in tracts oriented perpendicular to the main magnetic field. Measurements conducted at multiple repetition times suggest that the asymmetries are characterized by relatively small frequency shifts. These results are discussed in the context of previous work studying gradient-recalled echo (GRE) signal behavior in white matter, and it is suggested that these two techniques are detecting closely related phenomena.
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Affiliation(s)
- Karla L Miller
- Centre for Functional MRI of the Brain, University of Oxford, Oxford, UK.
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Enden T, Storås TH, Negård A, Haig Y, Sandvik L, Gjesdal KI, Sandset PM, Kløw NE. Visualization of deep veins and detection of deep vein thrombosis (DVT) with balanced turbo field echo (b-TFE) and contrast-enhanced T1 fast field echo (CE-FFE) using a blood pool agent (BPA). J Magn Reson Imaging 2010; 31:416-24. [DOI: 10.1002/jmri.22046] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Jung KJ. Synthesis methods of multiple phase-cycled SSFP images to reduce the band artifact and noise more reliably. Magn Reson Imaging 2010; 28:103-18. [DOI: 10.1016/j.mri.2009.05.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 05/19/2009] [Accepted: 05/19/2009] [Indexed: 10/20/2022]
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Bley TA, Wieben O, François CJ, Brittain JH, Reeder SB. Fat and water magnetic resonance imaging. J Magn Reson Imaging 2009; 31:4-18. [DOI: 10.1002/jmri.21895] [Citation(s) in RCA: 249] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Cukur T, Nishimura DG. Multiple repetition time balanced steady-state free precession imaging. Magn Reson Med 2009; 62:193-204. [PMID: 19449384 DOI: 10.1002/mrm.21990] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although balanced steady-state free precession (bSSFP) imaging yields high signal-to-noise ratio (SNR) efficiency, the bright lipid signal is often undesirable. The bSSFP spectrum can be shaped to suppress the fat signal with scan-efficient alternating repetition time (ATR) bSSFP. However, the level of suppression is limited, and the pass-band is narrow due to its nonuniform shape. A multiple repetition time (TR) bSSFP scheme is proposed that creates a broad stop-band with a scan efficiency comparable with ATR-SSFP. Furthermore, the pass-band signal uniformity is improved, resulting in fewer shading/banding artifacts. When data acquisition occurs in more than a single TR within the multiple-TR period, the echoes can be combined to significantly improve the level of suppression. The signal characteristics of the proposed technique were compared with bSSFP and ATR-SSFP. The multiple-TR method generates identical contrast to bSSFP, and achieves up to an order of magnitude higher stop-band suppression than ATR-SSFP. In vivo studies at 1.5 T and 3 T demonstrate the superior fat-suppression performance of multiple-TR bSSFP.
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Affiliation(s)
- Tolga Cukur
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305-9510, USA.
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Cukur T, Lee JH, Bangerter NK, Hargreaves BA, Nishimura DG. Non-contrast-enhanced flow-independent peripheral MR angiography with balanced SSFP. Magn Reson Med 2009; 61:1533-9. [PMID: 19365850 DOI: 10.1002/mrm.21921] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Flow-independent angiography is a non-contrast-enhanced technique that can generate vessel contrast even with reduced blood flow in the lower extremities. A method is presented for producing these angiograms with magnetization-prepared balanced steady-state free precession (bSSFP). Because bSSFP yields bright fat signal, robust fat suppression is essential for detailed depiction of the vasculature. Therefore, several strategies have been investigated to improve the reliability of fat suppression within short scan times. Phase-sensitive SSFP can efficiently suppress fat; however, partial volume effects due to fat and water occupying the same voxel can lead to the loss of blood signal. In contrast, alternating repetition time (ATR) SSFP minimizes this loss; however, the level of suppression is compromised by field inhomogeneity. Finally, a new double-acquisition ATR-SSFP technique reduces this sensitivity to off-resonance. In vivo results indicate that the two ATR-based techniques provide more reliable contrast when partial volume effects are significant.
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Affiliation(s)
- Tolga Cukur
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA.
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Cukur T, Lustig M, Nishimura DG. Improving non-contrast-enhanced steady-state free precession angiography with compressed sensing. Magn Reson Med 2009; 61:1122-31. [PMID: 19230013 DOI: 10.1002/mrm.21907] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Flow-independent angiography offers the ability to produce vessel images without contrast agents. Angiograms are acquired with magnetization-prepared three-dimensional balanced steady-state free precession sequences, where the phase encodes are interleaved and the preparation is repeated before each interleaf. The frequent repetition of the preparation significantly decreases the scan efficiency. The number of excitations can instead be reduced with compressed sensing by exploiting the compressibility of the angiograms. Hence, the phase encodes can be undersampled to save scan time without significantly degrading image quality. These savings can be allotted for preparing the magnetization more often, or alternatively, improving resolution. The enhanced resolution and contrast achieved with the proposed method are demonstrated with lower leg angiograms. Depiction of the vasculature is significantly improved with the increased resolution in the phase-encode plane and higher blood-to-background contrast.
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Affiliation(s)
- Tolga Cukur
- Department of Electrical Engineering, Stanford University, Stanford, California 94305-9510, USA.
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48
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Kijowski R, Blankenbaker DG, Davis KW, Shinki K, Kaplan LD, De Smet AA. Comparison of 1.5- and 3.0-T MR Imaging for Evaluating the Articular Cartilage of the Knee Joint. Radiology 2009; 250:839-48. [DOI: 10.1148/radiol.2503080822] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Cukur T, Nishimura DG. Fat-water separation with alternating repetition time balanced SSFP. Magn Reson Med 2008; 60:479-84. [PMID: 18666114 DOI: 10.1002/mrm.21692] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Balanced SSFP achieves high SNR efficiency, but suffers from bright fat signal. In this work, a multiple-acquisition fat-water separation technique using alternating repetition time (ATR) balanced SSFP is proposed. The SSFP profile can be modified using alternating repetition times and appropriate phase cycling to yield two spectra where fat and water are in-phase and out-of-phase, respectively. The signal homogeneity and the broad width of the created in-phase and out-of-phase profiles lead to signal cancellation over a broad stop-band. The stop-band suppression is achieved for a wide range of flip angles and tissue parameters. This property, coupled with the inherent flexibility of ATR SSFP in repetition time selection, makes the method a good candidate for fat-suppressed SSFP imaging. The proposed method can be tailored to achieve a smaller residual stop-band signal or a decreased sensitivity to field inhomogeneity depending on application-specific needs.
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Affiliation(s)
- Tolga Cukur
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA.
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50
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Lai P, Larson AC, Park J, Carr JC, Li D. Respiratory self-gated four-dimensional coronary MR angiography: a feasibility study. Magn Reson Med 2008; 59:1378-85. [PMID: 18506786 DOI: 10.1002/mrm.21617] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The four-dimensional (4D) coronary MR angiography (MRA) approach has been developed to eliminate the need for accurate determination of the acquisition window and trigger delay time. Diaphragm navigator (NAV) has been the conventional respiratory gating method for free-breathing coronary MRA. However, NAV echo acquisition interrupts the continuous radiofrequency pulse application required for 4D steady-state free precession coronary MRA. The objective of this work was to investigate the feasibility of a respiratory self-gating (RSG) technique for 4D coronary MRA and its effectiveness by comparing with retrospective NAV gating. Data were acquired continuously throughout the cardiac cycle and retrospectively remapped to cardiac phases based on the electrocardiogram signal simultaneously recorded. An RSG signal extracted from a direct measurement of the heart position was used for retrospective respiratory gating and motion correction. In seven healthy volunteers, 4D MRA images were reconstructed, allowing retrospective assessment of the cardiac motion of the coronary artery and selection of the images with the best vessel delineation. Statistical analysis shows that 4D RSG provides coronary artery delineation comparable to mid-diastole images acquired using NAV. Respiratory self-gating is an effective method for eliminating respiratory motion artifacts and allows 4D coronary MRA during free breathing.
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Affiliation(s)
- Peng Lai
- Department of Radiology, Northwestern University, Chicago, Illinois 60611, USA
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