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Hugon G, Adriaensen H, Wintrebert M, Arnould L, Serfaty JM, Robert P. Evaluation of the Contrast Enhancement Performance of Gadopiclenol for Magnetic Resonance Angiography in Healthy Rabbits and Pigs. Invest Radiol 2024; 59:614-621. [PMID: 38709660 DOI: 10.1097/rli.0000000000001083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
OBJECTIVES Unexpected accumulations of gadolinium in various organs were reported after the administration of gadolinium-based contrast agents, making desirable to reduce the dose while maintaining equivalent diagnostic performance. The aim of this study was to evaluate the contrast enhancement performance of high relaxivity gadopiclenol compared with gadoterate meglumine in abdominal contrast-enhanced magnetic resonance angiography (CE-MRA). MATERIALS AND METHODS In a first study in healthy rabbits, axial 3D gradient echo sequences were applied at 4.7 T to study arterial enhancement as a function of gadopiclenol dose (0.025, 0.05, 0.075, and 0.1 mmol Gd/kg) or gadoterate meglumine at 0.1 mmol Gd/kg (n = 5-6/group). The increase in signal-to-noise ratio (ΔSNR) in the aorta at the first pass was measured and compared. In a second, crossover study in 6 healthy pigs, abdominal CE-MRA sequences were acquired at 3 T with gadopiclenol at 0.05 mmol Gd/kg or gadoterate meglumine at 0.1 mmol Gd/kg at a 1-week interval. Quantitatively on the maximum intensity projection (MIP) images, the mean MIP SNR within the aorta of both groups was compared. Qualitatively, a blinded comparison of the angiograms was performed by an experienced radiologist to determine the preferred contrast agent. RESULTS In the rabbit, ∆SNR is linearly correlated with the gadopiclenol dose ( P = 0.0010). Compared with gadoterate meglumine 0.1 mmol Gd/kg, an increase in the ∆SNR is observed after 0.05, 0.075, and 0.1 mmol Gd/kg of gadopiclenol (+63% P = 0.0731, +78% P = 0.0081, and +72% P = 0.0773, respectively), whereas at 0.025 mmol Gd/kg, ∆SNR is in the same range as with gadoterate meglumine 0.1 mmol Gd/kg (+15% P > 0.9999). In pigs, contrast enhancement after gadopiclenol at 0.05 mmol/kg is +22% superior to MIP SNR after gadoterate meglumine at 0.1 mmol Gd/kg ( P = 0.3095). Qualitatively, a preference was shown for gadopiclenol images (3/6) over the gadoterate meglumine examinations (1/6), with no preference being shown for the remainder (2/6). CONCLUSIONS First-pass CE-MRA is feasible with gadopiclenol at 0.05 mmol Gd/kg with at least the same arterial signal enhancement and image quality as gadoterate meglumine at 0.1 mmol Gd/kg.
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Affiliation(s)
- Gaëlle Hugon
- From the Guerbet Research and Innovation, Guerbet, Roissy CdG, France (G.H., M.W., P.R.); INRAE, CNRS, Université de Tours, PRC, 37380, Nouzilly, France (H.A.); INRAE, Université de Tours, CHU de Tours, PIXANIM, 37380, Nouzilly, France (H.A.); Siemens Healthineers, Courbevoie-La Défense, France (L.A.); and Hôpital Guillaume et René Laennec, Department of Cardiovascular Radiology, Unité d'Imagerie Cardiaque et Vasculaire Diagnostique, Institut du Thorax-Clinique Cardiologique, Nantes, France (J.-M.S.)
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Bustamante M, Viola F, Carlhäll CJ, Ebbers T. Using Deep Learning to Emulate the Use of an External Contrast Agent in Cardiovascular 4D Flow MRI. J Magn Reson Imaging 2021; 54:777-786. [PMID: 33629795 DOI: 10.1002/jmri.27578] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/04/2021] [Accepted: 02/13/2021] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Although contrast agents would be beneficial, they are seldom used in four-dimensional (4D) flow magnetic resonance imaging (MRI) due to potential side effects and contraindications. PURPOSE To develop and evaluate a deep learning architecture to generate high blood-tissue contrast in noncontrast 4D flow MRI by emulating the use of an external contrast agent. STUDY TYPE Retrospective. SUBJECTS Of 222 data sets, 141 were used for neural network (NN) training (69 with and 72 without contrast agent). Evaluation was performed on the remaining 81 noncontrast data sets. FIELD STRENGTH/SEQUENCES Gradient echo or echo-planar 4D flow MRI at 1.5 T and 3 T. ASSESSMENT A cyclic generative adversarial NN was trained to perform image translation between noncontrast and contrast data. Evaluation was performed quantitatively using contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), structural similarity index (SSIM), mean squared error (MSE) of edges, and Dice coefficient of segmentations. Three observers performed a qualitative assessment of blood-tissue contrast, noise, presence of artifacts, and image structure visualization. STATISTICAL TESTS The Wilcoxon rank-sum test evaluated statistical significance. Kendall's concordance coefficient assessed interobserver agreement. RESULTS Contrast in the regions of interest (ROIs) in the NN enhanced images increased by 88%, CNR increased by 63%, and SNR improved by 48% (all P < 0.001). The SSIM was 0.82 ± 0.01, and the MSE of edges was 0.09 ± 0.01 (range [0,1]). Segmentations based on the generated images resulted in a Dice similarity increase of 15.25%. The observers managed to differentiate between contrast MR images and our results; however, they preferred the NN enhanced images in 76.7% of cases. This percentage increased to 93.3% for phase-contrast MR angiograms created from the NN enhanced data. Visual grading scores were blood-tissue contrast = 4.30 ± 0.74, noise = 3.12 ± 0.98, and presence of artifacts = 3.63 ± 0.76. Image structures within and without the ROIs resulted in scores of 3.42 ± 0.59 and 3.07 ± 0.71, respectively (P < 0.001). DATA CONCLUSION The proposed approach improves blood-tissue contrast in MR images and could be used to improve data quality, visualization, and postprocessing of cardiovascular 4D flow data. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 1.
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Affiliation(s)
- Mariana Bustamante
- Division of Diagnostics and Specialist Medicine, Department of Health Medicine and Caring Sciences, Linköping University, Linköping, Sweden.,Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Federica Viola
- Division of Diagnostics and Specialist Medicine, Department of Health Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Carl-Johan Carlhäll
- Division of Diagnostics and Specialist Medicine, Department of Health Medicine and Caring Sciences, Linköping University, Linköping, Sweden.,Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.,Department of Clinical Physiology in Linköping and Department of Health Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Tino Ebbers
- Division of Diagnostics and Specialist Medicine, Department of Health Medicine and Caring Sciences, Linköping University, Linköping, Sweden.,Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
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Srinivasan S, Hargreaves BA, Daniel BL. Fat-based registration of breast dynamic contrast enhanced water images. Magn Reson Med 2017; 79:2408-2414. [PMID: 28745402 DOI: 10.1002/mrm.26851] [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: 12/07/2016] [Revised: 06/25/2017] [Accepted: 07/04/2017] [Indexed: 12/17/2022]
Abstract
PURPOSE In this study, a 3D fat-based deformable registration algorithm was developed for registering dynamic contrast-enhanced breast images. METHODS The mutual information similarity measure with free-form deformation motion correction in rapidly enhancing lesions can introduce motion. However, in Dixon-based fat-water separated acquisitions, the nonenhancing fat signal can directly be used to estimate deformable motion, which can be later used to deform the water images. Qualitative comparison of the fat-based registration method to a water-based registration method, and to the unregistered images, was performed by two experienced readers. Quantitative analysis of the registration was evaluated by estimating the mean-squared signal difference on the fat images. RESULTS Using a scale of 0 (no motion) to 2 ( > 4 voxels of motion), the average image quality score of the fat-based registered images was 0.5 ± 0.6, water-based registration was 0.8 ± 0.8, and the unregistered dataset was 1.6 ± 0.6. The mean-squared-signal-difference metric on the fat images was significantly lower for fat-based registered images compared with both water-based registered and unregistered images. CONCLUSIONS Fat-based registration of breast dynamic contrast-enhanced images is a promising technique for performing deformable motion correction of breast without introducing new motion. Magn Reson Med 79:2408-2414, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
| | | | - Bruce L Daniel
- Department of Radiology, Stanford University, Stanford, California, USA
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Jost G, Endrikat J, Pietsch H. The Impact of Injector-Based Contrast Agent Administration on Bolus Shape and Magnetic Resonance Angiography Image Quality. MAGNETIC RESONANCE INSIGHTS 2017; 10:1178623X17705894. [PMID: 28579796 PMCID: PMC5428122 DOI: 10.1177/1178623x17705894] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 01/25/2017] [Indexed: 11/23/2022]
Abstract
Objective: To compare injector-based contrast agent (CA) administration with hand injection in magnetic resonance angiography (MRA). Methods: Gadobutrol was administered in 6 minipigs with 3 protocols: (a) hand injection (one senior technician), (b) hand injection (6 less-experienced technicians), and (c) power injector administration. The arterial bolus shape was quantified by test bolus measurements. A head and neck MRA was performed for quantitative and qualitative comparison of signal enhancement. Results: A significantly shorter time to peak was observed for protocol C, whereas no significant differences between protocols were found for peak height and bolus width. However, for protocol C, these parameters showed a much lower variation. The MRA revealed a significantly higher signal-to-noise ratio for injector-based administration. A superimposed strong contrast of the jugular vein was found in 50% of the hand injections. Conclusions: Injector-based CA administration results in a more standardized bolus shape, a higher vascular contrast, and a more robust visualization of target vessels.
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Affiliation(s)
- Gregor Jost
- MR and CT Contrast Media Research, Bayer AG, Berlin, Germany
| | - Jan Endrikat
- Global Medical & Clinical Affairs Radiology, Bayer AG, Berlin, Germany.,Department of Gynecology, Obstetrics and Reproductive Medicine, University Medical School of Saarland, Homburg, Germany
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Zhou Z, Han F, Rapacchi S, Nguyen KL, Brunengraber DZ, Kim GHJ, Finn JP, Hu P. Accelerated ferumoxytol-enhanced 4D multiphase, steady-state imaging with contrast enhancement (MUSIC) cardiovascular MRI: validation in pediatric congenital heart disease. NMR IN BIOMEDICINE 2017; 30:10.1002/nbm.3663. [PMID: 27862507 PMCID: PMC5298926 DOI: 10.1002/nbm.3663] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 10/04/2016] [Accepted: 10/05/2016] [Indexed: 05/09/2023]
Abstract
The purpose of this work was to validate a parallel imaging (PI) and compressed sensing (CS) combined reconstruction method for a recently proposed 4D non-breath-held, multiphase, steady-state imaging technique (MUSIC) cardiovascular MRI in a cohort of pediatric congenital heart disease patients. We implemented a graphics processing unit accelerated CS-PI combined reconstruction method and applied it in 13 pediatric patients who underwent cardiovascular MRI after ferumoxytol administration. Conventional breath-held contrast-enhanced magnetic resonance angiography (CE-MRA) was first performed during the first pass of ferumoxytol injection, followed by the original MUSIC and the proposed CS-PI MUSIC during the steady-state distribution phase of ferumoxytol. Qualities of acquired images were then evaluated using a four-point scale. Left ventricular volumes and ejection fractions calculated from the original MUSIC and the CS-PI MUSIC were also compared with conventional multi-slice 2D cardiac cine MRI. The proposed CS-PI MUSIC reduced the imaging time of the MUSIC acquisition to 4.6 ± 0.4 min from 8.9 ± 1.2 min. Computationally intensive image reconstruction was completed within 5 min without interruption of sequential clinical scans. The proposed method (mean 3.3-4.0) provided image quality comparable to that of the original MUSIC (3.2-4.0) (all P ≥ 0.42), and better than conventional breath-held first-pass CE-MRA (1.1-3.3) for 13 anatomical structures (all P ≤ 0.0014) with good inter-observer agreement (κ > 0.46). The calculated ventricular volumes and ejection fractions from both original MUSIC (r > 0.90) and CS-PI MUSIC (r > 0.85) correlated well with 2D cine imaging. In conclusion, PI and CS were successfully incorporated into the 4D MUSIC acquisition to further reduce scan time by approximately 50% while maintaining highly comparable image quality in a clinically practical reconstruction time.
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Affiliation(s)
- Ziwu Zhou
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Department of Bioengineering, University of California, Los Angeles, CA, USA
| | - Fei Han
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Department of Bioengineering, University of California, Los Angeles, CA, USA
| | - Stanislas Rapacchi
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Kim-Lien Nguyen
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Division of Cardiology, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Daniel Z Brunengraber
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Grace-Hyun J. Kim
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - J. Paul Finn
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, CA, USA
| | - Peng Hu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Department of Bioengineering, University of California, Los Angeles, CA, USA
- Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, CA, USA
- Correspondence to: Peng Hu, PhD, Department of Radiological Sciences, 300 UCLA Medical Plaza Suite B119, Los Angeles, CA 90095.
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Sofka CM. Technical Considerations: Best Practices for MR Imaging of the Foot and Ankle. Magn Reson Imaging Clin N Am 2016; 25:1-10. [PMID: 27888842 DOI: 10.1016/j.mric.2016.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
There are many challenges involved in obtaining diagnostic MR images of the foot and ankle. The complex anatomy and morphology, with curved and angular structures localized to the periphery of the body, make for an inherent challenge, let alone if an added level of complexity, such as orthopedic instrumentation, is added. This review outlines the technical considerations best designed to produce diagnostic images of the foot and ankle, with an emphasis on the postoperative state, including imaging in the presence of metal.
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Affiliation(s)
- Carolyn M Sofka
- Department of Radiology and Imaging, Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th Street, New York, NY 10021, USA.
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Lohrke J, Frenzel T, Endrikat J, Alves FC, Grist TM, Law M, Lee JM, Leiner T, Li KC, Nikolaou K, Prince MR, Schild HH, Weinreb JC, Yoshikawa K, Pietsch H. 25 Years of Contrast-Enhanced MRI: Developments, Current Challenges and Future Perspectives. Adv Ther 2016; 33:1-28. [PMID: 26809251 PMCID: PMC4735235 DOI: 10.1007/s12325-015-0275-4] [Citation(s) in RCA: 220] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Indexed: 12/17/2022]
Abstract
UNLABELLED In 1988, the first contrast agent specifically designed for magnetic resonance imaging (MRI), gadopentetate dimeglumine (Magnevist(®)), became available for clinical use. Since then, a plethora of studies have investigated the potential of MRI contrast agents for diagnostic imaging across the body, including the central nervous system, heart and circulation, breast, lungs, the gastrointestinal, genitourinary, musculoskeletal and lymphatic systems, and even the skin. Today, after 25 years of contrast-enhanced (CE-) MRI in clinical practice, the utility of this diagnostic imaging modality has expanded beyond initial expectations to become an essential tool for disease diagnosis and management worldwide. CE-MRI continues to evolve, with new techniques, advanced technologies, and novel contrast agents bringing exciting opportunities for more sensitive, targeted imaging and improved patient management, along with associated clinical challenges. This review aims to provide an overview on the history of MRI and contrast media development, to highlight certain key advances in the clinical development of CE-MRI, to outline current technical trends and clinical challenges, and to suggest some important future perspectives. FUNDING Bayer HealthCare.
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Affiliation(s)
- Jessica Lohrke
- MR and CT Contrast Media Research, Bayer HealthCare, Berlin, Germany
| | - Thomas Frenzel
- MR and CT Contrast Media Research, Bayer HealthCare, Berlin, Germany
| | - Jan Endrikat
- Global Medical Affairs Radiology, Bayer HealthCare, Berlin, Germany
- Saarland University Hospital, Homburg, Germany
| | | | - Thomas M Grist
- Radiology, Medical Physics and Biomedical Engineering, University of Wisconsin, Madison, WI, USA
| | - Meng Law
- Radiology and Neurological Surgery, University of South California, Keck School of Medicine, USC University Hospital, Los Angeles, CA, USA
| | - Jeong Min Lee
- College of Medicine, Seoul National University Hospital, Seoul, South Korea
| | - Tim Leiner
- Radiology, Utrecht University Medical Center, Utrecht, The Netherlands
| | - Kun-Cheng Li
- Radiology, Xuan Wu Hospital, Capital Medical University, Beijing, People's Republic of China
| | - Konstantin Nikolaou
- Radiology, Ludwig-Maximilians University, University Hospitals, Munich, Germany
| | - Martin R Prince
- Radiology, Weill Cornell Medical College, New York, NY, USA
- Columbia College of Physicians and Surgeons, New York, NY, USA
| | | | | | - Kohki Yoshikawa
- Graduate Division of Medical Health Sciences, Graduate School of Komazawa University, Tokyo, Japan
| | - Hubertus Pietsch
- MR and CT Contrast Media Research, Bayer HealthCare, Berlin, Germany.
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Homsi R, Gieseke J, Kukuk GM, Träber F, Willinek WA, Schild HH, Hadizadeh DR. Dixon-based fat-free MR-angiography compared to first pass and steady-state high-resolution MR-angiography using a blood pool contrast agent. Magn Reson Imaging 2015. [PMID: 26220860 DOI: 10.1016/j.mri.2015.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Compared to standard arterial-only first-pass MR-angiography (FPMRA), imaging during the equilibrium phase of a blood pool contrast agent (steady state) has been shown to provide higher image quality and better stenosis grading. Homogenous Dixon fat-suppression promises to increase contrast by suppression of fat adjacent to vessels. This study was performed to compare diagnostic image quality and vessel-to-background contrasts in equilibrium phase Dixon-based fat-free MRA (DFSMRA) of run-off vessels to FPMRA imaging and equilibrium phase T1-weighted non-fat-suppressed ultra-high resolution MRA (SSMRA). MATERIAL AND METHODS In a prospective, intra-individual comparative study, 17 patients with known or suspected peripheral arterial occlusive disease (PAOD; 11 men, mean age 65.6±18.1 [23-89] years) received FPMRA, DFSMRA, and SSMRA at 1.5 Tesla using a clinical whole body MRI scanner. All sequences were performed within the same session applying a single dose of a blood pool contrast agent (gadofosveset trisodium) that was injected during acquisition of FPMRA. The diagnostic image quality of the run-off vessels was evaluated on a 3-point scale. Quantitative analysis consisted of contrast-ratio (CR) measurements of vascular lumen signals compared to signals of adjacent muscle and fat. RESULTS The average image quality of vessel visualization was rated highest in SSMRA (mean 1.34±0.41), followed by standard FPMRA (mean 1.15±0.33) and DFSMRA (mean 0.99±0.61). Image quality was rated similarly high in the thighs and pelvic region, whereas small vessels in the lower legs and in the feet were best visualized by SSMRA. CR of vascular lumen compared to adjacent fatty tissue was 2.7 times higher in DFSMRA compared to SSMRA, whereas CR of vascular lumen to muscle was 1.3 times higher in SSMRA. CONCLUSION Vessel to fat contrast is strongly increased in DFSMRA compared to T1-weighted ultra-high resolution non-fat suppressed SSMRA, whereas vessel to muscle contrast is decreased in DFSMRA. Given the current technical limitations of DFSMRA, possible benefits are outweighed by advantages of first-pass imaging regarding arterial selectivity as well as advantages of SSMRA with respect to spatial resolution.
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Affiliation(s)
- Rami Homsi
- Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany
| | - Jürgen Gieseke
- Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany; Phillips Healthcare, Veenpluis 4, 5684 PC Best, Netherlands
| | - Guido M Kukuk
- Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany
| | - Frank Träber
- Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany
| | - Winfried A Willinek
- Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany; Center for Radiology, Neuroradiology, Sonography and Nuclear Medicine, Krankenhaus der Barmherzigen Brueder, Nordallee 1, 54292 Trier, Germany
| | - Hans H Schild
- Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany
| | - Dariusch R Hadizadeh
- Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany.
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Stinson EG, Trzasko JD, Weavers PT, Riederer SJ. Dixon-type and subtraction-type contrast-enhanced magnetic resonance angiography: A theoretical and experimental comparison of SNR and CNR. Magn Reson Med 2015; 74:81-92. [PMID: 25043453 PMCID: PMC4298483 DOI: 10.1002/mrm.25374] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 06/12/2014] [Accepted: 06/27/2014] [Indexed: 11/09/2022]
Abstract
PURPOSE The purpose of this work is to compare the behavior of the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in contrast-enhanced MR angiography with background suppression performed by either a Dixon-type or subtraction-type method. THEORY AND METHODS Theoretical expressions for the SNR and CNR for both background suppression techniques were derived. The theoretical Dixon:subtraction SNR and CNR ratios were compared to empirical ratios measured from phantom and in vivo studies for Dixon techniques utilizing one, two, and three echoes. Specifically, the SNR and CNR ratios were compared as the concentration of contrast material in the blood changed. RESULTS Empirical measurements of the SNR and CNR ratios compared favorably with the ratios predicted by theory. As the contrast concentration was reduced, the SNR advantage of the Dixon techniques increased asymptotically. In the ideal case, the SNR improvement over subtraction contrast-enhanced MR angiography was at least twofold for one- and two-echo Dixon techniques and at least a factor of 6 for the three-echo Dixon technique. CONCLUSION Expressions showing a contrast concentration-dependent SNR and CNR improvement of at least a factor of two when Dixon-type contrast-enhanced MR angiography is used in place of subtraction-type contrast-enhanced MR angiography were derived and validated with phantom and in vivo experiments. Magn Reson Med 74:81-92, 2015. © 2014 Wiley Periodicals, Inc.
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Affiliation(s)
- Eric G. Stinson
- Department of Radiology, Mayo Clinic, MR Research Laboratory, Rochester, Minnesota, USA
| | - Joshua D. Trzasko
- Department of Radiology, Mayo Clinic, MR Research Laboratory, Rochester, Minnesota, USA
| | - Paul T. Weavers
- Department of Radiology, Mayo Clinic, MR Research Laboratory, Rochester, Minnesota, USA
| | - Stephen J. Riederer
- Department of Radiology, Mayo Clinic, MR Research Laboratory, Rochester, Minnesota, USA
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Osting S, Bennett A, Power S, Wackett J, Hurley SA, Alexander AL, Agbandje-Mckena M, Burger C. Differential effects of two MRI contrast agents on the integrity and distribution of rAAV2 and rAAV5 in the rat striatum. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2014; 1:4. [PMID: 26015943 PMCID: PMC4365861 DOI: 10.1038/mtm.2013.4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 10/30/2013] [Indexed: 11/10/2022]
Abstract
Intraoperative magnetic resonance imaging (MRI) has been proposed as a method to optimize intracerebral targeting and for tracking infusate distribution in gene therapy trials for nervous system disorders. We thus investigated possible effects of two MRI contrast agents, gadoteridol (Gd) and galbumin (Gab), on the distribution and levels of transgene expression in the rat striatum and their effect on integrity and stability of recombinant adeno-associated virus (rAAV) particles. MRI studies showed that contrast agent distribution did not predict rAAV distribution. However, green fluorescent protein (GFP) immunoreactivity revealed an increase in distribution of rAAV5-GFP, but not rAAV2-GFP, in the presence of Gd when compared with viral vector injected alone. In contrast, Gab increased the distribution of rAAV2-GFP not rAAV5-GFP. These observations pointed to a direct effect of infused contrast agent on the rAAV particles. Negative-stain electron microscopy (EM), DNAase treatment, and differential scanning calorimetry (DSC) were used to monitor rAAV2 and rAAV5 particle integrity and stability following contrast agent incubation. EMs of rAAV2-GFP and rAAV5-GFP particles pretreated with Gd appear morphologically similar to the untreated sample; however, Gab treatment resulted in surface morphology changes and aggregation. A compromise of particle integrity was suggested by sensitivity of the packaged genome to DNAase treatment following Gab incubation but not Gd for both vectors. However, neither agent significantly affected particle stability when analyzed by DSC. An increase in T m was observed for AAV2 in lactated Ringer's buffer. These results thus highlight potential interactions between MRI contrast agents and AAV that might affect vector distribution and stability, as well as the stabilizing effect of lactated Ringer's solution on AAV2.
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Affiliation(s)
- Sue Osting
- Department of Neurology, University of Wisconsin , Madison, Wisconsin, USA
| | - Antonette Bennett
- Department of Biochemistry, University of Florida , Gainesville, Florida, USA
| | - Shelby Power
- Department of Neurology, University of Wisconsin , Madison, Wisconsin, USA
| | - Jordan Wackett
- Department of Neurology, University of Wisconsin , Madison, Wisconsin, USA
| | - Samuel A Hurley
- Department of Medical Physics, University of Wisconsin , Madison, Wisconsin, USA
| | - Andrew L Alexander
- Department of Medical Physics, University of Wisconsin , Madison, Wisconsin, USA ; Department of Psychiatry, University of Wisconsin , Madison, Wisconsin, USA ; Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin , Madison, Wisconsin, USA
| | | | - Corinna Burger
- Department of Neurology, University of Wisconsin , Madison, Wisconsin, USA
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Siegelman ES. Noncontrast-enhanced magnetic resonance imaging for evaluation of living renal donors. Acad Radiol 2013; 20:391-2. [PMID: 23498977 DOI: 10.1016/j.acra.2013.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 12/31/2012] [Accepted: 01/09/2013] [Indexed: 10/27/2022]
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Young PM, Mostardi PM, Glockner JF, Vrtiska TR, Macedo T, Haider CR, Riederer SJ. Prospective comparison of cartesian acquisition with projection-like reconstruction magnetic resonance angiography with computed tomography angiography for evaluation of below-the-knee runoff. J Vasc Interv Radiol 2013; 24:392-9. [PMID: 23433414 PMCID: PMC3593305 DOI: 10.1016/j.jvir.2012.11.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 11/05/2012] [Accepted: 11/08/2012] [Indexed: 11/19/2022] Open
Abstract
PURPOSE To compare prospectively the assessment of stenosis and radiologist confidence in the evaluation of below-the-knee lower extremity runoff vessels between computed tomography (CT) angiography and contrast-enhanced magnetic resonance (MR) angiography in a cohort of 19 clinical patients. MATERIALS AND METHODS The study was compliant with the Health Insurance Portability and Accountability Act of 1996 and approved by the institutional review board. Imaging was performed in 19 consecutive patients with known or suspected peripheral arterial disease; both CT angiography and a more recently developed MR angiography technique were performed within 24 hours of each other and before any therapeutic intervention. Resulting images were randomized and interpreted in blinded fashion by four board-certified radiologists with expertise in CT angiography and MR angiography. Vasculature of the lower leg was apportioned into 22 segments, 11 for each leg. For each segment, degree of stenosis and confidence of diagnosis were determined using a 3-point scale. Differences between CT angiography and MR angiography were assessed for significance using pooled histograms that were analyzed using the Wilcoxon signed rank test. RESULTS For assessment of stenosis, there was no difference in CT angiography compared with MR angiography for 20 of 22 segments. For confidence of diagnosis, assessment of popliteal arteries was superior on CT angiography compared with MR angiography (P<.05). Confidence in assessment of both tibioperoneal trunks and the left proximal anterior tibial artery was not significantly different between CT angiography and MR angiography. Confidence in assessment of all other 17 segments was superior with MR angiography compared with CT angiography (P<.02). CONCLUSIONS MR angiography using the method described here is a promising technique for evaluating lower extremity arterial runoff. MR angiography had an overall superior performance in radiologist confidence compared with CT angiography for imaging runoff vessels below the knee.
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Affiliation(s)
- Phillip M Young
- Department of Radiology, Mayo Clinic, Mayo 2, 200 First Street SW, Rochester, MN 55905, USA.
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15
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Wright KL, Seiberlich N, Jesberger JA, Nakamoto DA, Muzic RF, Griswold MA, Gulani V. Simultaneous magnetic resonance angiography and perfusion (MRAP) measurement: initial application in lower extremity skeletal muscle. J Magn Reson Imaging 2013; 38:1237-44. [PMID: 23389970 DOI: 10.1002/jmri.24020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 12/07/2012] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To obtain a simultaneous 3D magnetic resonance angiography and perfusion (MRAP) using a single acquisition and to demonstrate MRAP in the lower extremities. A time-resolved contrast-enhanced exam was used in MRAP to simultaneously acquire a contrast-enhanced MR angiography (MRA) and dynamic contrast-enhanced (DCE) perfusion, which currently requires separate acquisitions and thus two contrast doses. MRAP can be used to assess large and small vessels in vascular pathologies such as peripheral arterial disease. MATERIALS AND METHODS MRAP was performed on 10 volunteers following unilateral plantar flexion exercise (one leg exercised and one rested) on two separate days. Data were acquired after administration of a single dose of contrast agent using an optimized sampling strategy, parallel imaging, and partial-Fourier acquisition to obtain a high spatial resolution, 3D-MRAP frame every 4 seconds. Two radiologists assessed MRAs for image quality, a signal-to-noise ratio (SNR) analysis was performed, and pharmacokinetic modeling yielded perfusion (K(trans) ). RESULTS MRA images had high SNR and radiologist-assessed diagnostic quality. Mean K(trans) ± standard error were 0.136 ± 0.009, 0.146 ± 0.012, and 0.191 ± 0.012 min(-1) in the resting tibialis anterior, gastrocnemius, and soleus, respectively, which significantly increased with exercise to 0.291 ± 0.018, 0.270 ± 0.019, and 0.338 ± 0.022 min(-1) . Bland-Altman analysis showed good repeatability. CONCLUSION MRAP provides simultaneous high-resolution MRA and quantitative DCE exams to assess large and small vessels with a single contrast dose. Application in skeletal muscle shows quantitative, repeatable perfusion measurements, and the ability to measure physiological differences.
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Affiliation(s)
- Katherine L Wright
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA; Case Center for Imaging Research, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, USA
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Biglands JD, Radjenovic A, Ridgway JP. Cardiovascular magnetic resonance physics for clinicians: Part II. J Cardiovasc Magn Reson 2012; 14:66. [PMID: 22995744 PMCID: PMC3533879 DOI: 10.1186/1532-429x-14-66] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 09/13/2012] [Indexed: 01/08/2023] Open
Abstract
This is the second of two reviews that is intended to cover the essential aspects of cardiovascular magnetic resonance (CMR) physics in a way that is understandable and relevant to clinicians using CMR in their daily practice. Starting with the basic pulse sequences and contrast mechanisms described in part I, it briefly discusses further approaches to accelerate image acquisition. It then continues by showing in detail how the contrast behaviour of black blood fast spin echo and bright blood cine gradient echo techniques can be modified by adding rf preparation pulses to derive a number of more specialised pulse sequences. The simplest examples described include T2-weighted oedema imaging, fat suppression and myocardial tagging cine pulse sequences. Two further important derivatives of the gradient echo pulse sequence, obtained by adding preparation pulses, are used in combination with the administration of a gadolinium-based contrast agent for myocardial perfusion imaging and the assessment of myocardial tissue viability using a late gadolinium enhancement (LGE) technique. These two imaging techniques are discussed in more detail, outlining the basic principles of each pulse sequence, the practical steps required to achieve the best results in a clinical setting and, in the case of perfusion, explaining some of the factors that influence current approaches to perfusion image analysis. The key principles of contrast-enhanced magnetic resonance angiography (CE-MRA) are also explained in detail, especially focusing on timing of the acquisition following contrast agent bolus administration, and current approaches to achieving time resolved MRA. Alternative MRA techniques that do not require the use of an endogenous contrast agent are summarised, and the specialised pulse sequence used to image the coronary arteries, using respiratory navigator gating, is described in detail. The article concludes by explaining the principle behind phase contrast imaging techniques which create images that represent the phase of the MR signal rather than the magnitude. It is shown how this principle can be used to generate velocity maps by designing gradient waveforms that give rise to a relative phase change that is proportional to velocity. Choice of velocity encoding range and key pitfalls in the use of this technique are discussed.
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Affiliation(s)
- John D Biglands
- Division of Medical Physics, University of Leeds, Leeds, UK
- Department of Medical Physics and Engineering, Leeds Teaching Hospitals NHS Trust, 1st Floor, Bexley Wing, St James's University Hospital, Leeds, LS9 7TF, UK
- Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UK
| | - Aleksandra Radjenovic
- NIHR-Leeds Musculoskeletal Biomedical Research Unit and Leeds Institute of Molecular Medicine, University of Leeds, Leeds, UK
- Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UK
| | - John P Ridgway
- Department of Medical Physics and Engineering, Leeds Teaching Hospitals NHS Trust, 1st Floor, Bexley Wing, St James's University Hospital, Leeds, LS9 7TF, UK
- Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UK
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Nielsen YW, Thomsen HS. Contrast-enhanced peripheral MRA: technique and contrast agents. Acta Radiol 2012; 53:769-77. [PMID: 22843836 DOI: 10.1258/ar.2012.120008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast agents. Peripheral CE-MRA is defined as an MR angiogram of the arteries from the aortic bifurcation to the feet. Advantages of CE-MRA include minimal invasiveness and lack of ionizing radiation. The basic technique employed for peripheral CE-MRA is the bolus-chase method. With this method a paramagnetic MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic field strength of the MRI system, receiver coil configuration, use of parallel imaging, contrast bolus timing technique, and k-space filling strategies. Furthermore, it is possible to optimize peripheral CE-MRA using venous compression techniques, hybrid scan protocols, time-resolved imaging, and steady-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal insufficiency. Using optimized technique and a stable MRI contrast agent, peripheral CE-MRA is a safe procedure with diagnostic accuracy close to that of conventional catheter X-ray angiography.
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Affiliation(s)
- Yousef W Nielsen
- Deparment of Radiology, Copenhagen University Hospital Bispebjerg, Bispebjerg
| | - Henrik S Thomsen
- Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, Denmark
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Grist TM, Mistretta CA, Strother CM, Turski PA. Time‐resolved angiography: Past, present, and future. J Magn Reson Imaging 2012; 36:1273-86. [DOI: 10.1002/jmri.23646] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 02/17/2012] [Indexed: 11/08/2022] Open
Affiliation(s)
- Thomas M. Grist
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Charles A. Mistretta
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Charles M. Strother
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Patrick A. Turski
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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20
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Xu B, Spincemaille P, Chen G, Agrawal M, Nguyen TD, Prince MR, Wang Y. Fast 3D contrast enhanced MRI of the liver using temporal resolution acceleration with constrained evolution reconstruction. Magn Reson Med 2012; 69:370-81. [PMID: 22442108 DOI: 10.1002/mrm.24253] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 02/01/2012] [Accepted: 02/24/2012] [Indexed: 01/26/2023]
Abstract
Time-resolved imaging is crucial for the accurate diagnosis of liver lesions. Current contrast enhanced liver magnetic resonance imaging acquires a few phases in sequential breath-holds. The image quality is susceptible to bolus timing errors, which could result in missing the critical arterial phase. This impairs the detection of malignant tumors that are supplied primarily by the hepatic artery. In addition, the temporal resolution may be too low to reliably separate the arterial phase from the portal venous phase. In this study, a method called temporal resolution acceleration with constrained evolution reconstruction was developed with three-dimensional volume coverage and high-temporal frame rate. Data is acquired using a stack of spirals sampling trajectory combined with a golden ratio view order using an eight-channel coil array. Temporal frames are reconstructed from vastly undersampled data sets using a nonlinear inverse algorithm assuming that the temporal changes are small at short time intervals. Numerical and phantom experimental validation is presented. Preliminary in vivo results demonstrated high spatial resolution dynamic three-dimensional images of the whole liver with high frame rates, from which numerous subarterial phases could be easily identified retrospectively.
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Affiliation(s)
- Bo Xu
- Department of Radiology, Weill Cornell Medical College, New York, NY, USA
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22
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Nakamura M, Yoneyama M, Tabuchi T, Takemura A, Obara M, Sawano S. [Non-contrast time-resolved magnetic resonance angiography combining high resolution multiple phase echo planar imaging based signal targeting and alternating radiofrequency contrast inherent inflow enhanced multi phase angiography combining spatial resolution echo planar imaging based signal targeting and alternating radiofrequency in intracranial arteries]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2012; 68:1525-1532. [PMID: 23171775 DOI: 10.6009/jjrt.2012_jsrt_68.11.1525] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Detailed information on anatomy and hemodynamics in cerebrovascular disorders such as AVM and Moyamoya disease is mandatory for defined diagnosis and treatment planning. Arterial spin labeling technique has come to be applied to magnetic resonance angiography (MRA) and perfusion imaging in recent years. However, those non-contrast techniques are mostly limited to single frame images. Recently we have proposed a non-contrast time-resolved MRA technique termed contrast inherent inflow enhanced multi phase angiography combining spatial resolution echo planar imaging based signal targeting and alternating radiofrequency (CINEMA-STAR). CINEMA-STAR can extract the blood flow in the major intracranial arteries at an interval of 70 ms and thus permits us to observe vascular construction in full by preparing MIP images of axial acquisitions with high spatial resolution. This preliminary study demonstrates the usefulness of the CINEMA-STAR technique in evaluating the cerebral vasculature.
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Czum JM, Ho VB. MR of the Thoracic Aorta: A Pulse Sequence Approach to Discrete Feature Analysis. ACTA ACUST UNITED AC 2011. [DOI: 10.3109/10408379991249176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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24
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Haider CR, Riederer SJ, Borisch EA, Glockner JF, Grimm RC, Hulshizer TC, Macedo TA, Mostardi PM, Rossman PJ, Vrtiska TJ, Young PM. High temporal and spatial resolution 3D time-resolved contrast-enhanced magnetic resonance angiography of the hands and feet. J Magn Reson Imaging 2011; 34:2-12. [PMID: 21698702 DOI: 10.1002/jmri.22469] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Methods are described for generating 3D time-resolved contrast-enhanced magnetic resonance (MR) angiograms of the hands and feet. Given targeted spatial resolution and frame times, it is shown that acceleration of about one order of magnitude or more is necessary. This is obtained by a combination of 2D sensitivity encoding (SENSE) and homodyne (HD) acceleration methods. Image update times from 3.4-6.8 seconds are provided in conjunction with view sharing. Modular receiver coil arrays are described which can be designed to the targeted vascular region. Images representative of the technique are generated in the vasculature of the hands and feet in volunteers and in patient studies.
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Affiliation(s)
- Clifton R Haider
- Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905, USA
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Prospective Evaluation of High-Resolution MRI Using Gadofosveset for Stent-Graft Planning: Comparison With CT Angiography in 30 Patients. AJR Am J Roentgenol 2011; 197:1251-7. [DOI: 10.2214/ajr.10.6268] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Attenberger UI, Michaely HJ, Schoenberg SO, Rieger J. Imaging of non-atherosclerotic aneurysmal disease. Eur J Radiol 2011; 80:41-9. [DOI: 10.1016/j.ejrad.2010.12.100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 12/29/2010] [Indexed: 10/18/2022]
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Xu J, Shi D, Chen C, Li Y, Wang M, Han X, Jin L, Bi X. Noncontrast-enhanced four-dimensional MR angiography for the evaluation of cerebral arteriovenous malformation: a preliminary trial. J Magn Reson Imaging 2011; 34:1199-205. [PMID: 21769984 DOI: 10.1002/jmri.22699] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Accepted: 05/31/2011] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To prospectively evaluate noncontrast-enhanced (NCE), time resolved, four-dimensional (4D) magnetic resonance angiography (MRA) for assessment of cerebral arteriovenous malformation (AVM), with intraarterial digital subtraction angiography (DSA) performed as the reference standard. MATERIALS AND METHODS Fifteen patients (ten men, five women; age range 2-59 years, mean 29.4 years) with 15 untreated cerebral AVMs comprised the study population. NCE 4D MRA was performed on a 3.0 T MR scanner. MR images were reviewed by two independent readers and compared with DSA with respect to arterial feeders, nidus size, and venous drainage. Kappa coefficients of concordance were computed to determine the interobserver and intermodality agreements for the depiction of arterial feeders, nidus, and venous drainage between the two techniques. RESULTS Fifteen AVMs detected in DSA were visualized in NCE 4D MRA. Intermodality agreements were excellent for the arterial feeders (K = 0.918, P = 0.000), good for the nidus size (K = 0.692, P = 0.000), and moderate for the venous drainage (K = 0.495, P = 0.001). CONCLUSION NCE 4D MRA is a promising and potentially valuable method for noninvasive assessment of angioarchitecture and hemodynamics of cerebral AVMs. Further improvement of labeling persistence is desirable in order to enhance the depiction of draining veins for AVMs.
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Affiliation(s)
- Junling Xu
- Department of Radiology, Henan Provincial People's Hospital, Zhengzhou, China
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Hovnanian A, Menezes E, Hoette S, Jardim C, Jasinowodolinski D, Souza R. The role of imaging techniques in the assessment of pulmonary circulation. J Bras Pneumol 2011; 37:389-403. [PMID: 21755197 DOI: 10.1590/s1806-37132011000300017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 05/11/2011] [Indexed: 11/22/2022] Open
Abstract
Knowledge of the structure and function of pulmonary circulation has evolved considerably in the last few decades. The use of non-invasive imaging techniques to assess the anatomy and function of the pulmonary vessels and heart has taken on added importance with the recent advent of novel therapies. Imaging findings not only constitute a diagnostic tool but have also proven to be essential for prognosis and treatment follow-up. This article reviews the myriad of imaging methods currently available for the assessment of pulmonary circulation, from the simple chest X-ray to techniques that are more complex and promising, such as electrical impedance tomography.
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Affiliation(s)
- André Hovnanian
- Pulmonary Hypertension Group, Department of Pulmonology, Instituto do Coração, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - InCor/HCFMUSP, Heart Institute/University of São Paulo School of Medicine Hospital das Clínicas - São Paulo, Brazil
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Dynamic contrast-enhanced magnetic resonance angiography of the thoracic vessels: an intraindividual comparison of different k-space acquisition strategies. Invest Radiol 2011; 45:708-14. [PMID: 20548241 DOI: 10.1097/rli.0b013e3181e5bbb0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The combination of parallel acquisition (generalized autocalibrating partially parallel acquisitions) and time-resolved three-dimensional (3D) view-sharing techniques is a promising tool for dynamic contrast-enhanced 3D-magnetic resonance angiography (MRA). We evaluated the influence of different k-space acquisition strategies on image quality for a recently developed time-resolved echo-shared angiographic technique during a contrast-enhanced 3D-MRA of the thoracic vessels. MATERIALS AND METHODS In 20 patients (16 men, 4 women; range, 28-75 years), 2 dynamic MRA protocols with different k-space acquisition strategies were performed on a 1.5-T whole-body scanner (MAGNETOM Avanto, Siemens AG, Erlangen, Germany) during injection of 5 mL (flow-rate, 3 mL/s) gadobutrol. For protocol 1, the central-region which was updated with every cycle included 20% of the entire k-space (protocol 2: 10%), the peripheral-region was undersampled by a factor of 10 (protocol 2: 5%). Image quality and details were compared visually. Signal-to-noise ratio and sharpness of vessel borders were estimated. RESULTS Morphologic and functional assessment of the pulmonary arteries and the aorta was significantly improved for protocol 1. The sharpness of vessel borders (3.3 mm vs. 4.1 mm; P = 0.001), image quality, and the visibility of image details were significantly improved for protocol 1 compared with protocol 2. CONCLUSION The size of the central region that is updated for every frame seems to be more crucial for image quality of echo-shared angiographic techniques than the sampling density in the periphery of the k-space.
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Trzasko JD, Haider CR, Borisch EA, Campeau NG, Glockner JF, Riederer SJ, Manduca A. Sparse-CAPR: highly accelerated 4D CE-MRA with parallel imaging and nonconvex compressive sensing. Magn Reson Med 2011; 66:1019-32. [PMID: 21608028 DOI: 10.1002/mrm.22892] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 12/10/2010] [Accepted: 01/31/2011] [Indexed: 11/11/2022]
Abstract
Cartesian Acquisition with Projection-Reconstruction-like sampling is a SENSE-type parallel 3DFT acquisition paradigm for 4D contrast-enhanced magnetic resonance angiography that has been demonstrated capable of providing high spatial and temporal resolution, diagnostic-quality images at very high acceleration rates. However, Cartesian Acquisition with Projection-Reconstruction-like sampling images are typically reconstructed online using Tikhonov regularization and partial Fourier methods, which are prone to exhibit noise amplification and undersampling artifacts when operating at very high acceleration rates. In this work, a sparsity-driven offline reconstruction framework for Cartesian Acquisition with Projection-Reconstruction-like sampling is developed and demonstrated to consistently provide improvements over the currently-employed reconstruction strategy against these ill-effects. Moreover, the proposed reconstruction strategy requires no changes to the existing Cartesian Acquisition with Projection-Reconstruction-like sampling acquisition protocol, and an efficient numerical optimization and hardware system are described that allow for a 256 × 160 × 80 volume contrast-enhanced magnetic resonance angiography volume to be reconstructed from an eight-channel data set in less than 2 min.
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Affiliation(s)
- Joshua D Trzasko
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota 55905, USA
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31
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Yang Q, Li K, Li D. Coronary MRA: Technical Advances and Clinical Applications. CURRENT CARDIOVASCULAR IMAGING REPORTS 2011. [DOI: 10.1007/s12410-010-9064-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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32
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Rybicki FJ. MR Pulmonary angiography: assessment of PIOPED III data. Int J Cardiovasc Imaging 2011; 28:313-5. [PMID: 21347591 DOI: 10.1007/s10554-011-9835-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 02/14/2011] [Indexed: 11/25/2022]
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Garg SK, Mohan S, Kumar S. Diagnostic value of 3D contrast-enhanced magnetic resonance angiography in Takayasu’s arteritis—a comparative study with digital subtraction angiography. Eur Radiol 2011; 21:1658-66. [DOI: 10.1007/s00330-011-2090-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 01/06/2011] [Accepted: 01/20/2011] [Indexed: 10/18/2022]
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Haider CR, Borisch EA, Glockner JF, Mostardi PM, Rossman PJ, Young PM, Riederer SJ. Max CAPR: high-resolution 3D contrast-enhanced MR angiography with acquisition times under 5 seconds. Magn Reson Med 2011; 64:1171-81. [PMID: 20715291 DOI: 10.1002/mrm.22434] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
High temporal and spatial resolution is desired in imaging of vascular abnormalities having short arterial-to-venous transit times. Methods that exploit temporal correlation to reduce the observed frame time demonstrate temporal blurring, obfuscating bolus dynamics. Previously, a Cartesian acquisition with projection reconstruction-like (CAPR) sampling method has been demonstrated for three-dimensional contrast-enhanced angiographic imaging of the lower legs using two-dimensional sensitivity-encoding acceleration and partial Fourier acceleration, providing 1mm isotropic resolution of the calves, with 4.9-sec frame time and 17.6-sec temporal footprint. In this work, the CAPR acquisition is further undersampled to provide a net acceleration approaching 40 by eliminating all view sharing. The tradeoff of frame time and temporal footprint in view sharing is presented and characterized in phantom experiments. It is shown that the resultant 4.9-sec acquisition time, three-dimensional images sets have sufficient spatial and temporal resolution to clearly portray arterial and venous phases of contrast passage. It is further hypothesized that these short temporal footprint sequences provide diagnostic quality images. This is tested and shown in a series of nine contrast-enhanced MR angiography patient studies performed with the new method.
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Affiliation(s)
- Clifton R Haider
- MR Research Laboratory, Mayo Clinic, Rochester, Minnesota 55905, USA
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Mostardi PM, Haider CR, Glockner JF, Young PM, Riederer SJ. High spatial and temporal resolution imaging of the arterial vasculature of the lower extremity with contrast enhanced MR angiography. Clin Anat 2011; 24:478-88. [PMID: 21509813 DOI: 10.1002/ca.21124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 11/17/2010] [Accepted: 11/29/2010] [Indexed: 11/11/2022]
Abstract
Vascular imaging can be essential in the diagnosis, monitoring, and planning and assessment of treatment of patients with peripheral vascular disease. The purpose of this work is to describe a recently developed three-dimensional (3D) time-resolved contrast-enhanced MR angiography (CE-MRA) technique, Cartesian Acquisition with Projection Reconstruction-like sampling (CAPR), and its application to imaging of the vasculature of the lower legs and feet. CAPR implements accelerated imaging techniques and uses specialized multielement imaging coil arrays to achieve high temporal and high spatial resolution imaging. Volunteer and patient studies of the vasculature of the lower legs and feet have been performed. Temporal resolution of 4.9-6.5 sec and spatial resolution less than or equal to 1 mm in all directions allow for the depiction of progressive arterial filling and complex flow patterns as well as sharp visualization of vascular structure as small as the fine muscular branches. High-quality diagnostic imaging is made possible with CAPR's advanced acquisition and reconstruction techniques and the use of specialized coil arrays.
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Lee YJ, Laub G, Jung SL, Yoo WJ, Kim YJ, Ahn KJ, Kim BS. Low-dose 3D time-resolved magnetic resonance angiography (MRA) of the supraaortic arteries: Correlation with high spatial resolution 3D contrast-enhanced MRA. J Magn Reson Imaging 2010; 33:71-6. [PMID: 21182123 DOI: 10.1002/jmri.22396] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Youn-Joo Lee
- Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, South Korea
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Moriarty JM, Finn JP, Fonseca CG. Contrast agents used in cardiovascular magnetic resonance imaging: current issues and future directions. Am J Cardiovasc Drugs 2010; 10:227-37. [PMID: 20653329 DOI: 10.2165/11539370-000000000-00000] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Cardiovascular MRI is being increasingly used in the evaluation of ischemic heart disease, cardiac masses, complex congenital heart disease, and morphologic evaluation of the vascular anatomy throughout the body. Many and varied contrast media may be used to increase the sensitivity and specificity of detecting and evaluating various pathologies, and a knowledge of the different mechanisms of action, distributions and safety profiles of these agents is required for safe and effective imaging. This article reviews the currently available magnetic resonance (MR) contrast media, discusses the risks and benefits, and gives illustrated examples of current clinical applications in cardiovascular disease. A literature search covered the period 1990 to the present with the use of multiple databases including MEDLINE, PUBMED, SciSearch and Google Medical. All identified studies containing information relevant to the topic of cardiovascular MRI and cardiovascular MR contrast agents and their uses and properties were evaluated. Evaluation was limited to studies in English. The conclusions were that the use of contrast agents vastly increases the diagnostic yield, sensitivity and specificity of cardiovascular MRI in the non-invasive diagnosis of the full breadth of cardiovascular pathology. The use of contrast MRI for investigating ischemic heart disease, cardiac masses, and congenital heart disease and in angiography is now well established, and the referring physician, cardiologist, or radiologist requires an in-depth knowledge of the safety profiles and correct dosing of commonly prescribed contrast agents. As the number of MR contrast agents on the market continues to increase, knowledge of the basic mechanism of action is vital for keeping abreast of how new and emerging agents will affect clinical practice in the future.
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Affiliation(s)
- John M Moriarty
- Diagnostic Cardiovascular Imaging, Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA
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Nakamura K, Miyazaki M, Kuroki K, Yamamoto A, Hiramine A, Admiraal-Behloul F. Noncontrast-enhanced peripheral MRA: Technical optimization of flow-spoiled fresh blood imaging for screening peripheral arterial diseases. Magn Reson Med 2010; 65:595-602. [DOI: 10.1002/mrm.22614] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 07/27/2010] [Accepted: 08/04/2010] [Indexed: 11/06/2022]
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Chiribiri A, Morton G, Nagel E. Gadofosveset injection for magnetic resonance angiography. ACTA ACUST UNITED AC 2010. [DOI: 10.2217/iim.10.39] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bi X, Weale P, Schmitt P, Zuehlsdorff S, Jerecic R. Non-contrast-enhanced four-dimensional (4D) intracranial MR angiography: a feasibility study. Magn Reson Med 2010; 63:835-41. [PMID: 20187191 DOI: 10.1002/mrm.22220] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
T(1)-shortening contrast agents have been widely used in time-resolved magnetic resonance angiography. To match imaging data acquisition with the short time period of the first pass of contrast agent, temporal resolution and/or spatial resolution have to be compromised in many cases. In this study, a novel non-contrast-enhanced technique was developed for time-resolved magnetic resonance angiography. Alternating magnetization preparation was applied in two consecutive acquisitions of each measurement to eliminate the need for contrast media. Without the constraint of contrast media kinetics, temporal resolution is drastically improved from the order of a second as in conventional contrast-enhanced approach to tens of milliseconds (50.9 msec) in this study, without compromising spatial resolution. Initial results from volunteer studies demonstrate the feasibility of this method to depict anatomic structure and dynamic filling of main vessels in the head.
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Affiliation(s)
- Xiaoming Bi
- Siemens Medical Solutions USA, Inc., Chicago, Illinois 60611, USA.
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Meaney JFM, Fagan AJ, Beddy P. Magnetic resonance angiography of abdominal vessels at 3 T. Top Magn Reson Imaging 2010; 21:189-197. [PMID: 21847038 DOI: 10.1097/rmr.0b013e318228ca49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Magnetic resonance angiography (MRA) has evolved significantly since first described in the early 1990s. Unrivaled image quality and freedom from artifacts has made it a reliable and widely utilized technique. Imaging at 3 T offers the potential for higher resolutions images with better temporal resolution compared to 1.5 T. This article will review the technique and contrast agents required to perform MRA at 3 T and the relevant clinical applications. We also discuss non-contrast enhanced MRA in the era of nephrogenic systemic fibrosis and future prospect for MRA at 3 T.
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Affiliation(s)
- James F M Meaney
- Centre for Advanced Magnetic Resonance Imaging, St. James's Hospital, Dublin, Ireland.
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Bui BT, Miller S, Mildenberger P, Sam A, Sheng R. Comparison of contrast-enhanced MR angiography to intraarterial digital subtraction angiography for evaluation of peripheral arterial occlusive disease: Results of a phase III multicenter trial. J Magn Reson Imaging 2010; 31:1402-10. [DOI: 10.1002/jmri.22086] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Advantages of Blood Pooling in Pediatric MR Angiography⁎⁎Editorials published in JACC: Cardiovascular Imaging reflect the views of the authors and do not necessarily represent the views of JACC: Cardiovascular Imaging or the American College of Cardiology. JACC Cardiovasc Imaging 2010; 3:514-6. [PMID: 20466347 DOI: 10.1016/j.jcmg.2010.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Accepted: 03/10/2010] [Indexed: 11/21/2022]
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Contrast Material for Abdominal Dynamic Contrast-Enhanced 3D MR Angiography With Parallel Imaging: Intraindividual Equimolar Comparison of a Macrocyclic 1.0 M Gadolinium Chelate and a Linear Ionic 0.5 M Gadolinium Chelate. AJR Am J Roentgenol 2010; 194:821-9. [DOI: 10.2214/ajr.09.3306] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Garovic VD, Achauer MA, Kittner T, Horák D, Sheng R, Stanson AW. Comparison of gadodiamide-enhanced MR angiography to intraarterial digital subtraction angiography for evaluation of renal artery stenosis: Results of a phase III multicenter trial. J Magn Reson Imaging 2010; 31:390-7. [DOI: 10.1002/jmri.22032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Iozzelli A, D’Orta G, Aliprandi A, Secchi F, Di Leo G, Sardanelli F. The value of true-FISP sequence added to conventional gadolinium-enhanced MRA of abdominal aorta and its major branches. Eur J Radiol 2009; 72:489-93. [DOI: 10.1016/j.ejrad.2008.09.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 07/30/2008] [Accepted: 09/02/2008] [Indexed: 11/15/2022]
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Haider CR, Glockner JF, Stanson AW, Riederer SJ. Peripheral vasculature: high-temporal- and high-spatial-resolution three-dimensional contrast-enhanced MR angiography. Radiology 2009; 253:831-43. [PMID: 19789238 DOI: 10.1148/radiol.2533081744] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively evaluate the feasibility of performing high-spatial-resolution (1-mm isotropic) time-resolved three-dimensional (3D) contrast material-enhanced magnetic resonance (MR) angiography of the peripheral vasculature with Cartesian acquisition with projection-reconstruction-like sampling (CAPR) and eightfold accelerated two-dimensional (2D) sensitivity encoding (SENSE). MATERIALS AND METHODS All studies were approved by the institutional review board and were HIPAA compliant; written informed consent was obtained from all participants. There were 13 volunteers (mean age, 41.9; range, 27-53 years). The CAPR sequence was adapted to provide 1-mm isotropic spatial resolution and a 5-second frame time. Use of different receiver coil element sizes for those placed on the anterior-to-posterior versus left-to-right sides of the field of view reduced signal-to-noise ratio loss due to acceleration. Results from eight volunteers were rated independently by two radiologists according to prominence of artifact, arterial to venous separation, vessel sharpness, continuity of arterial signal intensity in major arteries (anterior and posterior tibial, peroneal), demarcation of origin of major arteries, and overall diagnostic image quality. MR angiographic results in two patients with peripheral vascular disease were compared with their results at computed tomographic angiography. RESULTS The sequence exhibited no image artifact adversely affecting diagnostic image quality. Temporal resolution was evaluated to be sufficient in all cases, even with known rapid arterial to venous transit. The vessels were graded to have excellent sharpness, continuity, and demarcation of the origins of the major arteries. Distal muscular branches and the communicating and perforating arteries were routinely seen. Excellent diagnostic quality rating was given for 15 (94%) of 16 evaluations. CONCLUSION The feasibility of performing high-diagnostic-quality time-resolved 3D contrast-enhanced MR angiography of the peripheral vasculature by using CAPR and eightfold accelerated 2D SENSE has been demonstrated.
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Affiliation(s)
- Clifton R Haider
- MR Research Laboratory and Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
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Wilson GJ, Maki JH. Non-contrast-enhanced MR imaging of renal artery stenosis at 1.5 tesla. Magn Reson Imaging Clin N Am 2009; 17:13-27. [PMID: 19364597 DOI: 10.1016/j.mric.2009.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Balanced steady-state free precession (Bal-SSFP) techniques produce excellent anatomic images of renal arteries without the use of contrast agents and are relatively flow-insensitive. Electrocardiography (ECG)-triggered and non-ECG-triggered sequences have been shown to be quite sensitive for detection of regional arterial stenosis (RAS), and the already high specificity is likely to increase with further refinement of the techniques. Bal-SSFP sequences can be used as a screening tool or as an alternative to contrast-enhanced (CE) magnetic resonance angiography (MRA) when contrast agents are contraindicated. In addition to morphologic imaging of RAS, non-CE techniques can be used in functional assessment of hemodynamic significance. The complimentary tools can be used alone or in combination with CE-MRA for MR imaging of renal vascular hypertension.
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Affiliation(s)
- Gregory J Wilson
- Department of Radiology (AA010-J), University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA; Philips Healthcare, Cleveland, OH, USA.
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Schroeder MA, Atherton HJ, Cochlin LE, Clarke K, Radda GK, Tyler DJ. The effect of hyperpolarized tracer concentration on myocardial uptake and metabolism. Magn Reson Med 2009; 61:1007-14. [PMID: 19253408 DOI: 10.1002/mrm.21934] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Hyperpolarized (13)C-labeled substrates directly provide a source of magnetic resonance (MR) signal to observe the substrates' real-time uptake and enzymatic conversion. The aim of this study was to optimize the concentration of hyperpolarized [1-(13)C]pyruvate infused as a metabolic tracer, by observing the mitochondrial conversion of pyruvate to H(13)CO(3)(-) in heart tissue. Hyperpolarized pyruvate was infused into rats at concentrations between 20 mM and 80 mM and the relationships between [1-(13)C]lactate, [1-(13)C]alanine, and H(13)CO(3)(-) production and the infused pyruvate concentration were investigated. H(13)CO(3)(-) production reached saturation above 40 mM infused pyruvate concentration, indicating that hyperpolarized MR experiments performed at this concentration maximize the H(13)CO(3)(-) signal with minimal alterations to in vivo substrate composition. Additionally, the linear dependence of alanine production on pyruvate concentration confirmed that hyperpolarized MR methods in the heart reveal enzyme activity, rather than cellular uptake. H(13)CO(3)(-) production demonstrated evidence of sigmoidal enzyme kinetics, a reflection of the allosteric nature of the pyruvate dehydrogenase (PDH) enzyme complex. This protocol could be useful to optimize the infused concentration of other hyperpolarized metabolites in different organs, to ensure adequate MR signal with minimum metabolic perturbation.
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Affiliation(s)
- Marie A Schroeder
- Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom
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