1
|
Jacobs PS, Brink W, Reddy R. A review of recent developments and applications of high-permittivity dielectric shimming in magnetic resonance. NMR IN BIOMEDICINE 2024; 37:e5094. [PMID: 38214202 DOI: 10.1002/nbm.5094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/20/2023] [Accepted: 11/29/2023] [Indexed: 01/13/2024]
Abstract
We present a review outlining the basic mechanism, background, recent technical developments, and clinical applications of aqueous dielectric padding in the field of MRI. Originally meant to be a temporary solution, it has gained traction as an effective method for correcting B1 + inhomogeneities due to the unique properties of the calcium titanate and barium titanate perovskites used. Aqueous dielectric pads have used a variety of high-permittivity materials over the years to improve the quality of MRI acquisitions at 1.5 and 3 T and more recently for 7 T neuroimaging applications. The technical development and assessment of these pads have been advanced by an increased use of mathematical modeling and electromagnetic simulations. These tools have allowed for a more complete understanding of the physical interactions between dielectric pads and the RF coil, making testing and safety assessments more accurate. The ease of use and effectiveness that dielectric pads offer have allowed them to become more commonplace in tackling imaging challenges in more clinically focused environments. More recently, they have seen usage not only in anatomical imaging methods but also in specialized metabolic imaging sequences such as GluCEST and NOEMTR . New colossally high-permittivity materials have been proposed; however, practical utilization has been a continued challenge due to unfavorable frequency dependences as well as safety limitations. A new class of metasurfaces has been under development to address the shortcomings of conventional dielectric padding while also providing increased performance in enhancing MRI images.
Collapse
Affiliation(s)
- Paul S Jacobs
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Wyger Brink
- Magnetic Detection and Imaging group, TechMed Centre, University of Twente, Enschede, The Netherlands
| | - Ravinder Reddy
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
2
|
Jain U, Soni S, Chauhan N. Application of perovskites in bioimaging: the state-of-the-art and future developments. Expert Rev Mol Diagn 2022; 22:867-880. [PMID: 36254607 DOI: 10.1080/14737159.2022.2135990] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND Recently, the development of perovskite-based nanocrystals for sustainable applications in bioimaging and clinical diagnostics have become a very active area of research. From 2D hybrid to zero-dimensional quantum dots (QDs), perovskites along with a variety of characteristic features, specifically non-linear optoelectronics properties, have attracted enormous research attention. These characteristics can be tuned by the type of cations or anions and their ratio used in host perovskites. Carrier doping and chemical modifications are additional alternatives to control optical and magnetism in radiodiagnostics. AREA COVERED This review begins by explaining the physical phenomena associated with luminescence or optical features of novel perovskites in diagnostic applications. Moreover, reported oxide, halide, doped, and QDs-based nanoprobes were elaborated. At last, the need for novel perovskite development, for example, persistent luminescent and low cytotoxicity is discussed, and the futuristic perspective of perovskites in clinical diagnostics with real-time demonstration is explained. EXPERT OPINION Our article concludes that hybrid perovskites, including metal-free, core-shell nanocomposites-based, and alloy-based perovskites, exhibit tunable bandgap and high photoluminescence quantum yields which ultimately result in high optical features. However, given limited understanding of ion transport mechanisms and dependency on environmental conditions of the perovskites, more research is needed.
Collapse
Affiliation(s)
- Utkarsh Jain
- School of Health Sciences & Technology (SoHST), University of Petroleum and Energy Studies (UPES), Bidholi, Dehradun 248007, India
| | - Shringika Soni
- Amity Institute of Nanotechnology (AINT), Amity University Uttar Pradesh (AUUP), Noida 201313, India
| | - Nidhi Chauhan
- School of Health Sciences & Technology (SoHST), University of Petroleum and Energy Studies (UPES), Bidholi, Dehradun 248007, India
| |
Collapse
|
3
|
Novel materials in magnetic resonance imaging: high permittivity ceramics, metamaterials, metasurfaces and artificial dielectrics. MAGNETIC RESONANCE MATERIALS IN PHYSICS, BIOLOGY AND MEDICINE 2022; 35:875-894. [PMID: 35471464 PMCID: PMC9596558 DOI: 10.1007/s10334-022-01007-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/18/2022] [Accepted: 03/07/2022] [Indexed: 11/01/2022]
Abstract
AbstractThis article reviews recent developments in designing and testing new types of materials which can be: (i) placed around the body for in vivo imaging, (ii) be integrated into a conventional RF coil, or (iii) form the resonator itself. These materials can improve the quality of MRI scans for both in vivo and magnetic resonance microscopy applications. The methodological section covers the basic operation and design of two different types of materials, namely high permittivity materials constructed from ceramics and artificial dielectrics/metasurfaces formed by coupled conductive subunits, either in air or surrounded by dielectric material. Applications of high permittivity materials and metasurfaces placed next to the body to neuroimaging and extremity imaging at 7 T, body and neuroimaging at 3 T, and extremity imaging at 1.5 T are shown. Results using ceramic resonators for both high field in vivo imaging and magnetic resonance microscopy are also shown. The development of new materials to improve MR image quality remains an active area of research, but has not yet found significant use in clinical applications. This is mainly due to practical issues such as specific absorption rate modelling, accurate and reproducible placement, and acceptable size/weight of such materials. The most successful area has been simple “dielectric pads” for neuroimaging at 7 T which were initially developed somewhat as a stop-gap while parallel transmit technology was being developed, but have continued to be used at many sites. Some of these issues can potentially be overcome using much lighter metasurfaces and artificial dielectrics, which are just beginning to be assessed.
Collapse
|
4
|
Raolison Z, Dubois M, Luong M, Neves AL, Mauconduit F, Enoch S, Mallejac N, Sabouroux P, Boumezbeur F, Berthault P, Zubkov M, Adenot-Engelvin AL, Hertz-Pannier L, Elodie G, Abdeddaim R, Vignaud A. Evaluation of new MR invisible silicon carbide based dielectric pads for 7 T MRI. Magn Reson Imaging 2022; 90:37-43. [DOI: 10.1016/j.mri.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 10/18/2022]
|
5
|
Vorobyev V, Shchelokova A, Efimtcev A, Baena JD, Abdeddaim R, Belov P, Melchakova I, Glybovski S. Improving B 1 + homogeneity in abdominal imaging at 3 T with light, flexible, and compact metasurface. Magn Reson Med 2021; 87:496-508. [PMID: 34314033 DOI: 10.1002/mrm.28946] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 01/11/2023]
Abstract
PURPOSE Radiofrequency field inhomogeneity is a significant issue in imaging large fields of view in high- and ultrahigh-field MRI. Passive shimming with coupled coils or dielectric pads is the most common approach at 3 T. We introduce and test light and compact metasurface, providing the same homogeneity improvement in clinical abdominal imaging at 3 T as a conventional dielectric pad. METHODS The metasurface comprising a periodic structure of copper strips and parallel-plate capacitive elements printed on a flexible polyimide substrate supports propagation of slow electromagnetic waves similar to a high-permittivity slab. We compare the metasurface operating inside a transmit body birdcage coil to the state-of-the-art pad by numerical simulations and in vivo study on healthy volunteers. RESULTS Numerical simulations with different body models show that the local minimum of B 1 + causing a dark void in the abdominal domain is removed by the metasurface with comparable resulting homogeneity as for the pad with decreasing maximum and whole-body SAR values. In vivo results confirm similar homogeneity improvement and demonstrate the stability to body mass index. CONCLUSION The light, flexible, and inexpensive metasurface can replace a relatively heavy and expensive pad based on the aqueous suspension of barium titanate in abdominal imaging at 3 T.
Collapse
Affiliation(s)
- Vsevolod Vorobyev
- School of Physics and Engineering, ITMO University, Saint Petersburg, Russia
| | - Alena Shchelokova
- School of Physics and Engineering, ITMO University, Saint Petersburg, Russia
| | - Alexander Efimtcev
- School of Physics and Engineering, ITMO University, Saint Petersburg, Russia.,Department of Radiology, Federal Almazov North-West Medical Research Center, Saint Petersburg, Russia
| | - Juan D Baena
- Department of Physics, Universidad Nacional de Colombia, Bogota, Colombia
| | - Redha Abdeddaim
- CNRS, Aix Marseille University, Marseille, France.,Institut Fresnel, Marseille, France
| | - Pavel Belov
- School of Physics and Engineering, ITMO University, Saint Petersburg, Russia
| | - Irina Melchakova
- School of Physics and Engineering, ITMO University, Saint Petersburg, Russia
| | - Stanislav Glybovski
- School of Physics and Engineering, ITMO University, Saint Petersburg, Russia
| |
Collapse
|
6
|
Vorobyev V, Shchelokova A, Zivkovic I, Slobozhanyuk A, Baena JD, Del Risco JP, Abdeddaim R, Webb A, Glybovski S. An artificial dielectric slab for ultra high-field MRI: Proof of concept. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 320:106835. [PMID: 33065392 DOI: 10.1016/j.jmr.2020.106835] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 09/02/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
High-permittivity dielectric pads, i.e., thin, flexible slabs, usually consisting of mixed ceramic powders and liquids, have been previously shown to increase the magnetic field at high and ultra high-fields in regions of low efficiency of transmit coils, thus improving the homogeneity of images. However, their material parameters can change with time, and some materials they contain are bio incompatible. This article presents an alternative approach replacing ceramic mixtures with a low-cost and stable artificial dielectric slab. The latter comprises a stack of capacitive grids realized using multiple printed-circuit boards. Results in this article show that the proposed artificial dielectric structure can obtain the same increase in the local transmit radiofrequency magnetic field distribution in a head phantom at 7 T as the conventional dielectric pad.
Collapse
Affiliation(s)
- Vsevolod Vorobyev
- Department of Physics and Engineering, ITMO University, 197101 St. Petersburg, Russia.
| | - Alena Shchelokova
- Department of Physics and Engineering, ITMO University, 197101 St. Petersburg, Russia.
| | - Irena Zivkovic
- Department of Radiology, C.J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden 2333 ZA, the Netherlands.
| | - Alexey Slobozhanyuk
- Department of Physics and Engineering, ITMO University, 197101 St. Petersburg, Russia.
| | - Juan D Baena
- Department of Physics, Universidad Nacional de Colombia, Bogota 111321, Colombia.
| | - Juan P Del Risco
- School of Exact Sciences and Engineering, Universidad Sergio Arboleda, Bogota 111711, Colombia.
| | - Redha Abdeddaim
- Aix Marseille University, CNRS, Centrale Marseille, Institut Fresnel, F-13013 Marseille, France.
| | - Andrew Webb
- Department of Radiology, C.J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden 2333 ZA, the Netherlands.
| | - Stanislav Glybovski
- Department of Physics and Engineering, ITMO University, 197101 St. Petersburg, Russia.
| |
Collapse
|
7
|
Ceramic resonators for targeted clinical magnetic resonance imaging of the breast. Nat Commun 2020; 11:3840. [PMID: 32737293 PMCID: PMC7395080 DOI: 10.1038/s41467-020-17598-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 06/25/2020] [Indexed: 12/02/2022] Open
Abstract
Currently, human magnetic resonance (MR) examinations are becoming highly specialized with a pre-defined and often relatively small target in the body. Conventionally, clinical MR equipment is designed to be universal that compromises its efficiency for small targets. Here, we present a concept for targeted clinical magnetic resonance imaging (MRI), which can be directly integrated into the existing clinical MR systems, and demonstrate its feasibility for breast imaging. The concept comprises spatial redistribution and passive focusing of the radiofrequency magnetic flux with the aid of an artificial resonator to maximize the efficiency of a conventional MR system for the area of interest. The approach offers the prospect of a targeted MRI and brings novel opportunities for high quality specialized MR examinations within any existing MR system. Here, the authors present a concept for targeted clinical magnetic resonance imaging for relatively small targets in the body. They use an artificial resonator for spatial redistribution and passive focusing of the radiofrequency magnetic flux and demonstrate feasibility for targeted breast imaging.
Collapse
|
8
|
Mitigation of B 1+ inhomogeneity for ultra-high-field magnetic resonance imaging: hybrid mode shaping with auxiliary EM potential. Sci Rep 2020; 10:11752. [PMID: 32678182 PMCID: PMC7366730 DOI: 10.1038/s41598-020-68651-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 06/29/2020] [Indexed: 11/25/2022] Open
Abstract
The notion of mode shaping based on evanescent coupling has been successfully applied in various fields of optics, such as in the dispersion engineering of optical waveguides. Here, we show that the same concept provides an opportunity for the seemingly different field of ultra-high-field MRI, addressing transmit RF magnetic field (B1+) inhomogeneity. In this work, treating the human phantom as a resonator, we employ an evanescently coupled high-index cladding layer to study the effects of the auxiliary potential on shaping the B1+ field distribution inside the phantom. Controlling the strength and coupling of the auxiliary potential ultimately determining the hybridized mode, we successfully demonstrate the global 2D homogenization of axial B1+ for a simplified cylindrical phantom and for a more realistic phantom of spheroidal geometry. The mode-shaping potentials with a magnetic permeability or material loss are also tested to offer additional degrees of freedom in the selection of materials as well as in the manipulation of the B1+ distribution, opening up the possibility of B1+ homogenization for 3D MRI scanning.
Collapse
|
9
|
Leroi L, Gras V, Boulant N, Ripart M, Poirion E, Santin MD, Valabregue R, Mauconduit F, Hertz‐Pannier L, Le Bihan D, Rochefort L, Vignaud A. Simultaneous proton density, T
1
, T
2
, and flip‐angle mapping of the brain at 7 T using multiparametric 3D SSFP imaging and parallel‐transmission universal pulses. Magn Reson Med 2020; 84:3286-3299. [DOI: 10.1002/mrm.28391] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Lisa Leroi
- Université Paris‐Saclay, CEA, CNRS, BAOBAB, NeuroSpin Gif‐sur‐Yvette France
| | - Vincent Gras
- Université Paris‐Saclay, CEA, CNRS, BAOBAB, NeuroSpin Gif‐sur‐Yvette France
| | - Nicolas Boulant
- Université Paris‐Saclay, CEA, CNRS, BAOBAB, NeuroSpin Gif‐sur‐Yvette France
| | - Mathilde Ripart
- Université Paris‐Saclay, CEA, CNRS, BAOBAB, NeuroSpin Gif‐sur‐Yvette France
| | - Emilie Poirion
- Université Paris‐Saclay, CEA, CNRS, BAOBAB, NeuroSpin Gif‐sur‐Yvette France
- ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S1127, Institut du Cerveau et de la Moelle Épinière Paris France
| | - Mathieu D. Santin
- ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S1127, Institut du Cerveau et de la Moelle Épinière Paris France
- CENIR, ICM, Hôpital Pitié‐Salpêtrière Paris France
| | - Romain Valabregue
- ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Université Paris 06 UMR S1127, Institut du Cerveau et de la Moelle Épinière Paris France
- CENIR, ICM, Hôpital Pitié‐Salpêtrière Paris France
| | - Franck Mauconduit
- Université Paris‐Saclay, CEA, CNRS, BAOBAB, NeuroSpin Gif‐sur‐Yvette France
| | | | - Denis Le Bihan
- Université Paris‐Saclay, CEA, CNRS, BAOBAB, NeuroSpin Gif‐sur‐Yvette France
| | - Ludovic Rochefort
- Aix‐Marseille University, CNRS, CRMBM (Center for Magnetic Resonance in Biology and Medicine‐UMR 7339) Marseille France
| | - Alexandre Vignaud
- Université Paris‐Saclay, CEA, CNRS, BAOBAB, NeuroSpin Gif‐sur‐Yvette France
| |
Collapse
|
10
|
Koutsoupidou M, Saha SC, Pricci RL, Cano-Garcia H, Palikaras G, Kosmas P, Kallos E. Metasurface Resonator for 1.5 T MRI Based on BaTiO 3 Host Material. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:6810-6813. [PMID: 31947404 DOI: 10.1109/embc.2019.8856404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Magnetic resonance imaging (MRI) is a widely used clinical tool for medical diagnosis and therapy. Several research studies focus on passively improving MRI sensitivity using high dielectric constant (HDC) materials and metamaterials. In this work, we investigate a new metasurface resonator which can enhance local transmit and receive efficiency in 1.5T MRI. The metasurface has been realized with an array of non-magnetic rods embedded in two blocks of a BaTiO3 aqueous mixture. BaTiO3 when mixed with water exhibits high dielectric permittivity values in the 40-200 MHz range, allowing the design of a compact and safe device for practical use in an MRI scanner. Simulation results show 50% enhancement of the magnetic field in the region-of-interest. The resonance frequency of the metasurface is also validated experimentally with a small loop antenna and a vector network analyzer (VNA) in a laboratory-controlled environment.
Collapse
|
11
|
Zivkovic I, Teeuwisse W, Slobozhanyuk A, Nenasheva E, Webb A. High permittivity ceramics improve the transmit field and receive efficiency of a commercial extremity coil at 1.5 Tesla. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 299:59-65. [PMID: 30580045 DOI: 10.1016/j.jmr.2018.12.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 12/07/2018] [Accepted: 12/14/2018] [Indexed: 06/09/2023]
Abstract
OBJECTIVE The purpose of this work is to investigate the use of ceramic materials (based on BaTiO3 with ZrO2 and CeO2-additives) with very high relative permittivity (εr ∼ 4500) to increase the local transmit field and signal-to-noise ratio (SNR) for commercial extremity coils on a clinical 1.5 T MRI system. METHODS Electromagnetic simulations of transmit efficiency and specific absorption rate (SAR) were performed using four ferroelectric ceramic blocks placed around a cylindrical phantom, as well as placing these ceramics around the wrist of a human body model. Results were compared with experimental scans using the transmit body coil of the 1.5 T MRI system and an eight-element extremity receive array designed for the wrist. SNR measurements were also performed for both phantom and in vivo scans. RESULTS Electromagnetic simulations and phantom/in vivo experiments showed an increased in the local transmit efficiency from the body coil of ∼20-30%, resulting in an ∼50% lower transmit power level and a significant reduction in local and global SAR throughout the body. For in vivo wrist experiments, the SNR of a commercial eight-channel receive array, integrated over the entire volume, was improved by ∼45% with the ceramic. CONCLUSION The local transmit efficiency as well as the SNR can be increased for 1.5 T extremity MRI with commercial array coils by using materials with very high permittivity.
Collapse
Affiliation(s)
- Irena Zivkovic
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Wouter Teeuwisse
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Alexey Slobozhanyuk
- Department of Nanophotonics and Metamaterials, ITMO University, Saint Petersburg, Russia
| | | | - Andrew Webb
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
| |
Collapse
|