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Willemink MJ, Coolen BF, Dyvorne H, Robson PM, Bander I, Ishino S, Pruzan A, Sridhar A, Zhang B, Balchandani P, Mani V, Strijkers GJ, Nederveen AJ, Leiner T, Fayad ZA, Mulder WJM, Calcagno C. Ultra-high resolution, 3-dimensional magnetic resonance imaging of the atherosclerotic vessel wall at clinical 7T. PLoS One 2020; 15:e0241779. [PMID: 33315867 PMCID: PMC7735577 DOI: 10.1371/journal.pone.0241779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/21/2020] [Indexed: 12/11/2022] Open
Abstract
Accurate quantification and characterization of atherosclerotic plaques with MRI requires high spatial resolution acquisitions with excellent image quality. The intrinsically better signal-to-noise ratio (SNR) at high-field clinical 7T compared to the widely employed lower field strengths of 1.5 and 3T may yield significant improvements to vascular MRI. However, 7T atherosclerosis imaging also presents specific challenges, related to local transmit coils and B1 field inhomogeneities, which may overshadow these theoretical gains. We present the development and evaluation of 3D, black-blood, ultra-high resolution vascular MRI on clinical high-field 7T in comparison lower-field 3T. These protocols were applied for in vivo imaging of atherosclerotic rabbits, which are often used for development, testing, and validation of translatable cardiovascular MR protocols. Eight atherosclerotic New Zealand White rabbits were imaged on clinical 7T and 3T MRI scanners using 3D, isotropic, high (0.63 mm3) and ultra-high (0.43 mm3) spatial resolution, black-blood MR sequences with extensive spatial coverage. Following imaging, rabbits were sacrificed for validation using fluorescence imaging and histology. Image quality parameters such as SNR and contrast-to-noise ratio (CNR), as well as morphological and functional plaque measurements (plaque area and permeability) were evaluated at both field strengths. Using the same or comparable imaging parameters, SNR and CNR were in general higher at 7T compared to 3T, with a median (interquartiles) SNR gain of +40.3 (35.3-80.1)%, and a median CNR gain of +68.1 (38.5-95.2)%. Morphological and functional parameters, such as vessel wall area and permeability, were reliably acquired at 7T and correlated significantly with corresponding, widely validated 3T vessel wall MRI measurements. In conclusion, we successfully developed 3D, black-blood, ultra-high spatial resolution vessel wall MRI protocols on a 7T clinical scanner. 7T imaging was in general superior to 3T with respect to image quality, and comparable in terms of plaque area and permeability measurements.
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Affiliation(s)
- Martin J. Willemink
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
- Department of Radiology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Bram F. Coolen
- Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Hadrien Dyvorne
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Philip M. Robson
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Ilda Bander
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Seigo Ishino
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Alison Pruzan
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Arthi Sridhar
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Bei Zhang
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Priti Balchandani
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Venkatesh Mani
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Gustav J. Strijkers
- Department of Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Aart J. Nederveen
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Tim Leiner
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Zahi A. Fayad
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Willem J. M. Mulder
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Medical Biochemistry, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - Claudia Calcagno
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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Cahn BA, Shah JT, Dyvorne H, O'Halloran R, Poole M, Yuen MM, Mazurek MH, Ward A, Payabvash S, Beekman R, Brown SC, Falcone G, Gobeske K, Petersen N, Jasne A, Sharma R, Schindler J, Sansing L, Gilmore E, Wira C, Matouk C, Sze G, Rosen M, Kimberly WT, Sheth KN. Abstract 57: Deployment of Portable, Bedside, Low-Field Magnetic Resonance Imaging for Evaluation of Stroke Patients. Stroke 2020. [DOI: 10.1161/str.51.suppl_1.57] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
Magnetic resonance imaging (MRI) is a powerful modality for diagnosing stroke. Conventionally, patients must travel to the location of a high-field MRI device. Advances in low-field MRI have enabled acquisition of clinically useful images using a portable device at the bedside. The feasibility of using point of care (POC) MRI in a clinical stroke setting is unknown.
Objective:
To determine the safety and feasibility of portable, bedside, low-field MRI in a clinical setting.
Design/Methods:
POC MRI exams were performed in Yale’s Neuroscience Intensive Care Unit (NICU) from July 2018 to August 2019. Images were acquired at the bedside using a standard 110V, 15A power outlet. The environment included the bedside vitals monitor, ventilators and intravenous infusion pumps. Exams were performed by research staff trained to operate the POC scanner in the absence of a trained MRI technician. No special precautions were necessary to remove ferrous metals from the room. Scan parameters were controlled using a tablet computer interface, and images were available immediately after acquisition.
Results:
POC MRI was obtained in 85 stroke cases (46% female, ages 18-96 years, 46% ischemic stroke, 34% intracerebral hemorrhage, 20% subarachnoid hemorrhage). Scans were obtained within 7 days of symptom onset. NIHSS scores ranged from 1 to 29 (median of 7). Of the 85 patients analyzed, 68 underwent T2-weighted imaging, 72 underwent FLAIR imaging, and 39 underwent diffusion weighted imaging (DWI). DWI was only tested in ischemic stroke cases. Patients’ BMI ranged from 20.0 to 46.5 with a median of 26.7. The majority 74 (87%) of patients completed the entire exam. Five patients (6%) were unable to fit in the scanner’s 30 cm opening, while 6 patients (7%) experienced claustrophobia resulting in early termination of the exam. Mean exam time was 28.9 ± 8.4 minutes. The 64 mT static magnetic field, gradient and RF pulses of the POC MRI scanner did not interfere with NICU equipment, and no significant adverse events occurred.
Conclusions:
We report the first use of a portable, low-field MRI system to image stroke patients at the bedside. This early work suggests our approach is safe and viable in a complex clinical care environment.
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Affiliation(s)
| | - Jill T Shah
- Dept of Neurology, Yale Sch of Medicine, New Haven, CT
| | | | | | | | | | | | - Adrienne Ward
- Dept of Neurology, Yale Sch of Medicine, New Haven, CT
| | - Sam Payabvash
- Dept of Radiology, Yale Sch of Medicine, New Haven, CT
| | | | - Stacy C Brown
- Dept of Neurology, Yale Sch of Medicine, New Haven, CT
| | - Guido Falcone
- Dept of Neurology, Yale Sch of Medicine, New Haven, CT
| | - Kevin Gobeske
- Dept of Neurology, Yale Sch of Medicine, New Haven, CT
| | - Nils Petersen
- Dept of Neurology, Yale Sch of Medicine, New Haven, CT
| | - Adam Jasne
- Dept of Neurology, Yale Sch of Medicine, New Haven, CT
| | - Richa Sharma
- Dept of Neurology, Yale Sch of Medicine, New Haven, CT
| | | | | | - Emily Gilmore
- Dept of Neurology, Yale Sch of Medicine, New Haven, CT
| | - Charles Wira
- Dept of Emergency Medicine, Yale Sch of Medicine, New Haven, CT
| | - Charles Matouk
- Dept of Neurosurgery, Yale Sch of Medicine, New Haven, CT
| | - Gordon Sze
- Dept of Radiology, Yale Sch of Medicine, New Haven, CT
| | | | | | - Kevin N Sheth
- Dept of Neurology, Yale Sch of Medicine, New Haven, CT
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Schlemper J, Salehi SSM, Kundu P, Lazarus C, Dyvorne H, Rueckert D, Sofka M. Nonuniform Variational Network: Deep Learning for Accelerated Nonuniform MR Image Reconstruction. Lecture Notes in Computer Science 2019. [DOI: 10.1007/978-3-030-32248-9_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Bane O, Peti S, Wagner M, Hectors S, Dyvorne H, Markl M, Taouli B. Hemodynamic measurements with an abdominal 4D flow MRI sequence with spiral sampling and compressed sensing in patients with chronic liver disease. J Magn Reson Imaging 2018; 49:994-1005. [PMID: 30318674 DOI: 10.1002/jmri.26305] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/30/2018] [Accepted: 07/31/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The test-retest/interobserver repeatability and diagnostic value of 4D flow MRI in liver disease is underreported. PURPOSE To determine the reproducibility/repeatability of flow quantification in abdominal vessels using a spiral 4D flow MRI sequence; to assess the value of 4D flow parameters in diagnosing cirrhosis and degree of portal hypertension. STUDY TYPE Prospective. SUBJECTS Fifty-two patients with chronic liver disease. FIELD STRENGTH/SEQUENCE 1.5T/spiral 4D flow acquired in one breath-hold. ASSESSMENT Thirteen abdominal vessels were identified and segmented by two independent observers to measure maximum and time-averaged through-plane velocity, net flow, and vessel cross-section area. Interobserver agreement and test-retest repeatability were evaluated in 15 and 4 cases, respectively. Prediction of the presence and severity of cirrhosis and portal hypertension was assessed using 4D flow parameters. STATISTICAL TESTS Cohen's kappa coefficient, coefficient of variation (CV), Bland-Altman, Mann-Whitney tests, logistic regression. RESULTS For all vessels combined, measurements showed acceptable agreement between observers, with Cohen's kappa = 0.70 (P < 0.001), CV < 21%, Bland-Altman bias <5%, but high limits of agreement ([-75%,75%]). Test-retest repeatability was excellent in large vessels (CV = 1-15%, bias = 1-25%, Bland-Altman limits of agreement [BALA] = [4%,150%]), and poor in small vessels (CV = 7-130%, bias = 10-200%, BALA = [8%,190%]). Average velocity in the right hepatic vein and average area of the splenic vein were higher in cirrhosis (P = 0.027/0.0039). Flow in the middle hepatic vein strongly correlated with Child-Pugh score (ρ = 0.84, P = 0.0238), while flow in the splenic vein (ρ = 0.43, P = 0.032), time-average (ρ = 0.46, P = 0.02) and peak velocity in the superior mesenteric vein (ρ = 0.45, P = 0.032), and peak velocity in the infrarenal IVC (ρ = 0.39, P = 0.032) positively correlated with an imaging-based portal hypertension score. Average area of the splenic vein predicted cirrhosis (P = 0.019; area under the curve AUC [95% confidence interval, CI] = 0.87 [0.71,1.00]) and clinically significant portal hypertension (P = 0.042; AUC [95% CI] = 0.78 [0.57-0.99]). DATA CONCLUSION Spiral 4D flow allows comprehensive assessment of abdominal vessels in one breath-hold, with substantial interobserver reproducibility, but variable test-retest repeatability. 4D flow may potentially reflect vascular changes due to cirrhosis and portal hypertension. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:994-1005.
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Affiliation(s)
- Octavia Bane
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Steven Peti
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Mathilde Wagner
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Department of Radiology, Groupe Hospitalier Pitié Salpêtrière, Paris, France
| | - Stefanie Hectors
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Hadrien Dyvorne
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Catalyzer, Guilford, Connecticut, USA
| | - Michael Markl
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.,Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, USA
| | - Bachir Taouli
- Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Rohani Rankouhi S, Hong D, Dyvorne H, Balchandani P, Norris DG. MASE-sLASER, a short-TE, matched chemical shift displacement error sequence for single-voxel spectroscopy at ultrahigh field. NMR Biomed 2018; 31:e3940. [PMID: 29856517 DOI: 10.1002/nbm.3940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 04/03/2018] [Accepted: 04/09/2018] [Indexed: 06/08/2023]
Abstract
B1 inhomogeneity and chemical shift displacement error (CSDE) increase with the main magnetic field strength and are therefore deleterious for magnetic resonance spectroscopy (MRS) at ultrahigh field. A solution is to use adiabatic pulses which operate over a broad range of B1 and thus are insensitive to B1 inhomogeneity. Moreover, adiabatic pulses usually have a relatively higher bandwidth, which makes CSDE low to negligible. The use of exclusively adiabatic pulses for single-voxel spectroscopy (SVS) typically brings the disadvantage of a long echo time (TE), but the advantage of a low and matched CSDE. Herein, we took advantage of short-duration, low-power, matched-phase adiabatic spin echo (MASE) pulses to implement a matched CSDE semi-localized by adiabatic selective refocusing (sLASER) sequence capable of attaining short TEs, while CSDE is matched and still comparatively low. We also demonstrate here the feasibility of the direct measurement of the γ-aminobutyric acid (GABA) resonance at 2.28 ppm well separated from the neighboring glutamate resonance at 7 T using the implemented MASE-sLASER sequence at TEs of 68 and 136 ms. The shorter duration of MASE pulses also made it possible to implement a Mescher-Garwood-semi-localized by adiabatic selective refocusing (MEGA-sLASER) (with MASE) sequence with TE = 68 ms for editing GABA at 7 T, the results for which are also shown.
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Affiliation(s)
- Seyedmorteza Rohani Rankouhi
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany
| | - Donghyun Hong
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
| | - Hadrien Dyvorne
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Priti Balchandani
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - David G Norris
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, the Netherlands
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Dyvorne H, Balchandani P. Slice-selective adiabatic magnetization T 2 -preparation (SAMPA) for efficient T 2 -weighted imaging at ultrahigh field strengths. Magn Reson Med 2015; 76:1741-1749. [PMID: 26619960 DOI: 10.1002/mrm.26067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/27/2015] [Accepted: 10/31/2015] [Indexed: 12/29/2022]
Abstract
PURPOSE At high field, T2 -weighted (T2 w) imaging is limited by transmit field inhomogeneity and increased radiofrequency power deposition. In this work, we introduce SAMPA (Slice-selective Adiabatic Magnetization T2 PrepAration) and demonstrate its use for efficient brain T2 w imaging at 7 Tesla (T). METHODS SAMPA was designed by subsampling an optimized B1 insensitive rotation (BIR4) waveform with small tip angle linear subpulses. To perform T2 w imaging, SAMPA was inserted before a fast gradient echo acquisition. The off-resonance behavior, B1 robustness, and slice selectivity of the novel T2 preparation module were analyzed using Bloch simulations. The performance of SAMPA for T2 w imaging was demonstrated in phantom experiments as well as in the brains of healthy volunteers at 7T. RESULTS Based on simulations, the proposed design operates at peak B1 of 15 μT and higher, within a 400 Hz bandwidth. T2 values were in strong agreement with spin echo-based T2 mapping in phantom experiments. Whole brain, interleaved multislab three-dimensional imaging could be acquired with 0.8 mm3 isotropic resolution in 5:36 min per T2 weighting. CONCLUSION Compared with previous adiabatic T2 preparation techniques, SAMPA allows for slice-selectivity, which can lead to efficient and robust acquisitions for T2 w imaging at high field. Magn Reson Med 76:1741-1749, 2016. © 2015 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Hadrien Dyvorne
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Priti Balchandani
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Calcagno C, Lobatto ME, Dyvorne H, Robson PM, Millon A, Senders ML, Lairez O, Ramachandran S, Coolen BF, Black A, Mulder WJM, Fayad ZA. Three-dimensional dynamic contrast-enhanced MRI for the accurate, extensive quantification of microvascular permeability in atherosclerotic plaques. NMR Biomed 2015; 28:1304-14. [PMID: 26332103 PMCID: PMC4573915 DOI: 10.1002/nbm.3369] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 06/19/2015] [Accepted: 07/06/2015] [Indexed: 05/28/2023]
Abstract
Atherosclerotic plaques that cause stroke and myocardial infarction are characterized by increased microvascular permeability and inflammation. Dynamic contrast-enhanced MRI (DCE-MRI) has been proposed as a method to quantify vessel wall microvascular permeability in vivo. Until now, most DCE-MRI studies of atherosclerosis have been limited to two-dimensional (2D) multi-slice imaging. Although providing the high spatial resolution required to image the arterial vessel wall, these approaches do not allow the quantification of plaque permeability with extensive anatomical coverage, an essential feature when imaging heterogeneous diseases, such as atherosclerosis. To our knowledge, we present the first systematic evaluation of three-dimensional (3D), high-resolution, DCE-MRI for the extensive quantification of plaque permeability along an entire vascular bed, with validation in atherosclerotic rabbits. We compare two acquisitions: 3D turbo field echo (TFE) with motion-sensitized-driven equilibrium (MSDE) preparation and 3D turbo spin echo (TSE). We find 3D TFE DCE-MRI to be superior to 3D TSE DCE-MRI in terms of temporal stability metrics. Both sequences show good intra- and inter-observer reliability, and significant correlation with ex vivo permeability measurements by Evans Blue near-infrared fluorescence (NIRF). In addition, we explore the feasibility of using compressed sensing to accelerate 3D DCE-MRI of atherosclerosis, to improve its temporal resolution and therefore the accuracy of permeability quantification. Using retrospective under-sampling and reconstructions, we show that compressed sensing alone may allow the acceleration of 3D DCE-MRI by up to four-fold. We anticipate that the development of high-spatial-resolution 3D DCE-MRI with prospective compressed sensing acceleration may allow for the more accurate and extensive quantification of atherosclerotic plaque permeability along an entire vascular bed. We foresee that this approach may allow for the comprehensive and accurate evaluation of plaque permeability in patients, and may be a useful tool to assess the therapeutic response to approved and novel drugs for cardiovascular disease.
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Affiliation(s)
- Claudia Calcagno
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Mark E Lobatto
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Radiology, Academisch Medisch Centrum, Amsterdam, the Netherlands
| | - Hadrien Dyvorne
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Philip M Robson
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Antoine Millon
- Department of Vascular Surgery, University Hospital of Lyon, Lyon, France
| | - Max L Senders
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Olivier Lairez
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Cardiac Imaging Center, University Hospital of Rangueil, Toulouse, France
| | - Sarayu Ramachandran
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Bram F Coolen
- Department of Radiology, Academisch Medisch Centrum, Amsterdam, the Netherlands
| | - Alexandra Black
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Willem J M Mulder
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Radiology, Academisch Medisch Centrum, Amsterdam, the Netherlands
| | - Zahi A Fayad
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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8
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Dyvorne H, O'Halloran R, Balchandani P. Ultrahigh field single-refocused diffusion weighted imaging using a matched-phase adiabatic spin echo (MASE). Magn Reson Med 2015; 75:1949-57. [PMID: 26041650 DOI: 10.1002/mrm.25790] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 04/27/2015] [Accepted: 04/30/2015] [Indexed: 12/24/2022]
Abstract
PURPOSE To improve ultrahigh field diffusion-weighted imaging (DWI) in the presence of inhomogeneous transmit B1 field by designing a novel semi-adiabatic single-refocused DWI technique. METHODS A 180° slice-selective, adiabatic radiofrequency (RF) pulse of 4 ms duration was designed using the adiabatic Shinnar-Le Roux algorithm. A matched-phase slice-selective 90° RF pulse of 8 ms duration was designed to compensate the nonlinear phase of the adiabatic 180° RF pulse. The resulting RF pulse combination, matched-phase adiabatic spin echo (MASE), was integrated into a single-shot echo planar DWI sequence. The performance of this sequence was compared with single-refocused Stejskal-Tanner (ST), twice-refocused spin echo (TRSE) and twice-refocused adiabatic spin echo (TRASE) in simulations, phantoms, and healthy volunteers at 7 Tesla (T). RESULTS In regions with inhomogeneous B1 , MASE resulted in increased signal intensity compared with ST (up to 64%). Moderate increase in specific absorption rate (35-39%) was observed for adiabatic RF pulses. MASE resulted in higher signal homogeneity at 7T, leading to improved visualization of measures derived from diffusion-weighted images such as white matter tractography and track density images. CONCLUSION Efficient adiabatic SLR pulses can be adapted to single-refocused DWI, leading to substantially improved signal uniformity when compared with conventional acquisitions.
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Affiliation(s)
- Hadrien Dyvorne
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Rafael O'Halloran
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Priti Balchandani
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Abstract
Purpose To compare intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) of the liver between 1.5 T and 3.0 T in terms of parameter quantification and inter-platform reproducibility. Materials and methods In this IRB approved prospective study, 19 subjects (17 patients with chronic liver disease and 2 healthy volunteers) underwent two repeat scans at 1.5 T and 3.0 T. Each scan included IVIM DWI using 16 b values from 0 to 800 s/mm2. A single observer measured IVIM parameters for each platform and estimated signal to noise ratio (eSNR) at b0, 200, 400 and 800 s/mm2. Wilcoxon paired tests were used to compare liver eSNR and IVIM parameters. Inter-platform reproducibility was assessed by calculating within-subject coefficient of variation (CV) and Bland–Altman limits of agreement. An ice water phantom was used to test ADC variability between the two MRI systems. Results The mean invitro difference in ADC between the two platforms was 6.8%. eSNR was significantly higher at 3.0T for all selected b values (p = 0.006–0.020), except for b0 (p = 0.239). Liver IVIM parameters were significantly different between 1.5 T and 3.0 T (p = 0.005–0.044), except for ADC (p = 0.748). The inter-platform reproducibility of true diffusion coefficient (D) and ADC were good, with mean CV of 10.9% and 11.1%, respectively. Perfusion fraction (PF) and pseudodiffusion coefficient (D*) showed more limited inter-platform reproducibility (mean CV of 22.6% for PF and 46.9% for D*). Conclusion Liver D and ADC values showed good reproducibility between 1.5 T and 3.0 T platforms; while there was more variability in PF, and large variability in D* parameters between the two platforms. These findings may have implications for drug trials assessing the role of IVIM DWI in tumor response and liver fibrosis.
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Affiliation(s)
- Yong Cui
- Department of Radiology/Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029 USA
| | - Hadrien Dyvorne
- Department of Radiology/Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029 USA
| | - Cecilia Besa
- Department of Radiology/Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029 USA
| | - Nancy Cooper
- Department of Radiology/Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029 USA
| | - Bachir Taouli
- Department of Radiology/Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029 USA
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10
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Dyvorne H, Knight-Greenfield A, Jajamovich G, Besa C, Cui Y, Stalder A, Markl M, Taouli B. Abdominal 4D flow MR imaging in a breath hold: combination of spiral sampling and dynamic compressed sensing for highly accelerated acquisition. Radiology 2014; 275:245-54. [PMID: 25325326 DOI: 10.1148/radiol.14140973] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE To develop a highly accelerated phase-contrast cardiac-gated volume flow measurement (four-dimensional [4D] flow) magnetic resonance (MR) imaging technique based on spiral sampling and dynamic compressed sensing and to compare this technique with established phase-contrast imaging techniques for the quantification of blood flow in abdominal vessels. MATERIALS AND METHODS This single-center prospective study was compliant with HIPAA and approved by the institutional review board. Ten subjects (nine men, one woman; mean age, 51 years; age range, 30-70 years) were enrolled. Seven patients had liver disease. Written informed consent was obtained from all participants. Two 4D flow acquisitions were performed in each subject, one with use of Cartesian sampling with respiratory tracking and the other with use of spiral sampling and a breath hold. Cartesian two-dimensional (2D) cine phase-contrast images were also acquired in the portal vein. Two observers independently assessed vessel conspicuity on phase-contrast three-dimensional angiograms. Quantitative flow parameters were measured by two independent observers in major abdominal vessels. Intertechnique concordance was quantified by using Bland-Altman and logistic regression analyses. RESULTS There was moderate to substantial agreement in vessel conspicuity between 4D flow acquisitions in arteries and veins (κ = 0.71 and 0.61, respectively, for observer 1; κ = 0.71 and 0.44 for observer 2), whereas more artifacts were observed with spiral 4D flow (κ = 0.30 and 0.20). Quantitative measurements in abdominal vessels showed good equivalence between spiral and Cartesian 4D flow techniques (lower bound of the 95% confidence interval: 63%, 77%, 60%, and 64% for flow, area, average velocity, and peak velocity, respectively). For portal venous flow, spiral 4D flow was in better agreement with 2D cine phase-contrast flow (95% limits of agreement: -8.8 and 9.3 mL/sec, respectively) than was Cartesian 4D flow (95% limits of agreement: -10.6 and 14.6 mL/sec). CONCLUSION The combination of highly efficient spiral sampling with dynamic compressed sensing results in major acceleration for 4D flow MR imaging, which allows comprehensive assessment of abdominal vessel hemodynamics in a single breath hold.
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Affiliation(s)
- Hadrien Dyvorne
- From the Department of Radiology/Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave, New York, NY 10029 (H.D., A.K., G.J., C.B., Y.C., B.T.); Healthcare Sector, Imaging & Therapy Division, Siemens, Erlangen, Germany (A.S.); and Department of Radiology and Biomedical Engineering, Feinberg School of Medicine, Northwestern University, Chicago, Ill (M.M.)
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11
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Dyvorne H, Jajamovich G, Kakite S, Kuehn B, Taouli B. Intravoxel incoherent motion diffusion imaging of the liver: optimal b-value subsampling and impact on parameter precision and reproducibility. Eur J Radiol 2014; 83:2109-2113. [PMID: 25277521 DOI: 10.1016/j.ejrad.2014.09.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 09/03/2014] [Accepted: 09/07/2014] [Indexed: 12/21/2022]
Abstract
PURPOSE To increase diffusion sampling efficiency in intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) of the liver by reducing the number of diffusion weightings (b-values). MATERIALS AND METHODS In this IRB approved HIPAA compliant prospective study, 53 subjects (M/F 38/15, mean age 52 ± 13 y) underwent IVIM DWI at 1.5T using 16 b-values (0-800s/mm(2)), with 14 subjects having repeat exams to assess IVIM parameter reproducibility. A biexponential diffusion model was used to quantify IVIM hepatic parameters (PF: perfusion fraction, D: true diffusion and D*: pseudo diffusion). All possible subsets of the 16 b-values were probed, with number of b values ranging from 4 to 15, and corresponding parameters were quantified for each subset. For each b-value subset, global parameter estimation error was computed against the parameters obtained with all 16 b-values and the subsets providing the lowest error were selected. Interscan estimation error was also evaluated between repeat exams to assess reproducibility of the IVIM technique in the liver. The optimal b-values distribution was selected such that the number of b-values was minimal while keeping parameter estimation error below interscan reproducibility error. RESULTS As the number of b-values decreased, the estimation error increased for all parameters, reflecting decreased precision of IVIM metrics. Using an optimal set of 4 b-values (0, 15, 150 and 800s/mm(2)), the errors were 6.5, 22.8 and 66.1% for D, PF and D* respectively. These values lie within the range of test-retest reproducibility for the corresponding parameters, with errors of 12.0, 32.3 and 193.8% for D, PF and D* respectively. CONCLUSION A set of 4 optimized b-values can be used to estimate IVIM parameters in the liver with significantly shorter acquisition time (up to 75%), without substantial degradation of IVIM parameter precision and reproducibility compared to the 16 b-value acquisition used as the reference.
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Affiliation(s)
- Hadrien Dyvorne
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029, United States.
| | - Guido Jajamovich
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029, United States.
| | - Suguru Kakite
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029, United States.
| | - Bernd Kuehn
- Siemens AG, Healthcare Sector, Erlangen, Germany.
| | - Bachir Taouli
- Department of Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, New York, NY 10029, United States.
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12
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Abstract
Diffusion-weighted imaging (DWI) is a technique that assesses the cellularity, tortuosity of the extracellular/extravascular space, and cell membrane density based on differences in water proton mobility in tissues. The strength of the diffusion weighting is reflected by the b value. DWI using several b values enables the quantification of the apparent diffusion coefficient. DWI is increasingly used in liver imaging for multiple reasons: it can add useful qualitative and quantitative information to conventional imaging sequences; it is acquired relatively quickly; it is easily incorporated into existing clinical protocols; and it is a noncontrast technique.
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Affiliation(s)
- Sara Lewis
- Department of Radiology, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, Box 1234, New York, NY 10029, USA
| | - Hadrien Dyvorne
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, Box 1234, New York, NY 10029, USA
| | - Yong Cui
- Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, Box 1234, New York, NY 10029, USA
| | - Bachir Taouli
- Department of Radiology, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, Box 1234, New York, NY 10029, USA; Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, One Gustave Levy Place, Box 1234, New York, NY 10029, USA.
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13
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Jajamovich GH, Dyvorne H, Donnerhack C, Taouli B. Quantitative liver MRI combining phase contrast imaging, elastography, and DWI: assessment of reproducibility and postprandial effect at 3.0 T. PLoS One 2014; 9:e97355. [PMID: 24840288 PMCID: PMC4026225 DOI: 10.1371/journal.pone.0097355] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 04/17/2014] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To quantify short-term reproducibility (in fasting conditions) and postprandial changes after a meal in portal vein (PV) flow parameters measured with phase contrast (PC) imaging, liver diffusion parameters measured with multiple b value diffusion-weighted imaging (DWI) and liver stiffness (LS) measured with MR elastography (MRE) in healthy volunteers and patients with liver disease at 3.0 T. MATERIALS AND METHODS In this IRB-approved prospective study, 30 subjects (11 healthy volunteers and 19 liver disease patients; 23 males, 7 females; mean age 46.5 y) were enrolled. Imaging included 2D PC imaging, multiple b value DWI and MRE. Subjects were initially scanned twice in fasting state to assess short-term parameter reproducibility, and then scanned 20 min. after a liquid meal. PV flow/velocity, LS, liver true diffusion coefficient (D), pseudodiffusion coefficient (D*), perfusion fraction (PF) and apparent diffusion coefficient (ADC) were measured in fasting and postprandial conditions. Short-term reproducibility was assessed in fasting conditions by measuring coefficients of variation (CV) and Bland-Altman limits of agreement. Differences in MR metrics before and after caloric intake and between healthy volunteers and liver disease patients were assessed. RESULTS PV flow parameters, D, ADC and LS showed good to excellent short-term reproducibility in fasting state (CV <16%), while PF and D* showed acceptable and poor reproducibility (CV = 20.4% and 51.6%, respectively). PV flow parameters and LS were significantly higher (p<0.04) in postprandial state while liver diffusion parameters showed no significant change (p>0.2). LS was significantly higher in liver disease patients compared to healthy volunteers both in fasting and postprandial conditions (p<0.001). Changes in LS were significantly correlated with changes in PV flow (Spearman rho = 0.48, p = 0.013). CONCLUSIONS Caloric intake had no/minimal/large impact on diffusion/stiffness/portal vein flow, respectively. PC MRI and MRE but not DWI should be performed in controlled fasting state.
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Affiliation(s)
- Guido H. Jajamovich
- Translational and Molecular Imaging Institute, Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Hadrien Dyvorne
- Translational and Molecular Imaging Institute, Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Claudia Donnerhack
- Translational and Molecular Imaging Institute, Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
| | - Bachir Taouli
- Translational and Molecular Imaging Institute, Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States
- * E-mail:
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14
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Kakite S, Dyvorne H, Besa C, Cooper N, Facciuto M, Donnerhack C, Taouli B. Hepatocellular carcinoma: short-term reproducibility of apparent diffusion coefficient and intravoxel incoherent motion parameters at 3.0T. J Magn Reson Imaging 2014; 41:149-56. [PMID: 24415565 DOI: 10.1002/jmri.24538] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 11/05/2013] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To evaluate short-term test-retest and interobserver reproducibility of IVIM (intravoxel incoherent motion) diffusion parameters and ADC (apparent diffusion coefficient) of hepatocellular carcinoma (HCC) and liver parenchyma at 3.0T. MATERIALS AND METHODS In this prospective Institutional Review Board (IRB)-approved study, 11 patients were scanned twice using a free-breathing single-shot echo-planar-imaging, diffusion-weighted imaging (DWI) sequence using 4 b values (b = 0, 50, 500, 1000 s/mm(2)) and IVIM DWI using 16 b values (0-800 s/mm(2)) at 3.0T. IVIM parameters (D: true diffusion coefficient, D*: pseudodiffusion coefficient, PF: perfusion fraction) and ADC (using 4 b and 16 b) were calculated. Short-term test-retest and interobserver reproducibility of IVIM parameters and ADC were assessed by measuring correlation coefficient, coefficient of variation (CV), and Bland-Altman limits of agreements (BA-LA). RESULTS Fifteen HCCs were assessed in 10 patients. Reproducibility of IVIM metrics in HCC was poor for D* and PF (mean CV 60.6% and 37.3%, BA-LA: -161.6% to 135.3% and -66.2% to 101.0%, for D* and PF, respectively), good for D and ADC (CV 19.7% and <16%, BA-LA -57.4% to 36.3% and -38.2 to 34.1%, for D and ADC, respectively). Interobserver reproducibility was on the same order of test-retest reproducibility except for PF in HCC. Reproducibility of diffusion parameters was better in liver parenchyma compared to HCC. CONCLUSION Poor reproducibility of D*/PF and good reproducibility for D/ADC were observed in HCC and liver parenchyma. These findings may have implications for trials using DWI in HCC.
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Affiliation(s)
- Suguru Kakite
- Department of Radiology/Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Herreros Q, Dyvorne H, Campiglio P, Jasmin-Lebras G, Demonti A, Pannetier-Lecoeur M, Fermon C. Very low field magnetic resonance imaging with spintronic sensors. Rev Sci Instrum 2013; 84:095116. [PMID: 24089875 DOI: 10.1063/1.4821657] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A very low field magnetic resonance imaging (MRI) setup based on magnetoresistive-superconducting mixed sensors is presented. A flux transformer is used to achieve coupling between the sample to image and the mixed sensor. The novel detector was implemented in a spin echo MRI experiment, exposing the mixed sensor to RF pulses without use of any RF switch. The performance of the novel detector is given in terms of signal-to-noise ratio and is compared with classical tuned coils.
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Affiliation(s)
- Q Herreros
- DSM∕IRAMIS∕SPEC-CNRS URA 2464, CEA Saclay, F-91191 Gif sur Yvette Cedex, France
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Dyvorne H, Scola J, Fermon C, Jacquinot JF, Pannetier-Lecoeur M. Flux transformers made of commercial high critical temperature superconducting wires. Rev Sci Instrum 2008; 79:025107. [PMID: 18315329 DOI: 10.1063/1.2885610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We have designed flux transformers made of commercial BiSCCO tapes closed by soldering with normal metal. The magnetic field transfer function of the flux transformer was calculated as a function of the resistance of the soldered contacts. The performances of different kinds of wires were investigated for signal delocalization and gradiometry. We also estimated the noise introduced by the resistance and showed that the flux transformer can be used efficiently for weak magnetic field detection down to 1 Hz.
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Affiliation(s)
- H Dyvorne
- Service de Physique de L'Etat Condensé, DSM/DRECAM/SPEC, CEA-Saclay, 91191 Gif-sur-Yvette, France.
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