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Edsall C, Fergusson A, Davis RM, Meyer CH, Allen SP, Vlaisavljevich E. Probability of Cavitation in a Custom Iron-Based Coupling Medium for Transcranial Magnetic Resonance-Guided Focused Ultrasound Procedures. ULTRASOUND IN MEDICINE & BIOLOGY 2023; 49:2519-2526. [PMID: 37730478 PMCID: PMC10591864 DOI: 10.1016/j.ultrasmedbio.2023.08.015] [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: 04/30/2023] [Revised: 06/13/2023] [Accepted: 08/16/2023] [Indexed: 09/22/2023]
Abstract
OBJECTIVE A coupling bath of circulating, chilled, degassed water is essential to safe and precise acoustic transmittance during transcranial magnetic resonance-guided focused ultrasound (tMRgFUS) procedures, but the circulating water impairs the critical real-time magnetic resonance imaging (MRI). An iron-based coupling medium (IBCM) using iron oxide nanoparticles previously developed by our group increased the relaxivity of the coupling bath such that it appears to be invisible on MRI compared with degassed water. However, the nanoparticles also reduced the pressure threshold for cavitation. To address this concern for prefocal cavitation, our group recently developed an IBCM of electrosterically stabilized and aggregation-resistant poly(methacrylic acid)-coated iron oxide nanoparticles (PMAA-FeOX) with a similar capability to reduce the MR signal of degassed water. This study examines the effect of the PMAA-FeOX IBCM on the cavitation threshold. METHODS Increasing concentrations of PMAA-FeOX nanoparticles in degassed, deionized water were placed at the focus of two different transducers to assess low and high duty-cycle pulsing parameters which are representative of two modes of focused ultrasound being investigated for tMRgFUS. Passive cavitation detection and high-speed optical imaging were used to measure cavitation threshold pressures. RESULTS The mean cavitation threshold was determined in both cases to be indistinguishable from the degassed water control, between 6-8 MPa for high duty-cycle pulsing (CW) and between 25.5-26.5 MPa for very low duty-cycle pulsing. CONCLUSION The findings of this study indicate that an IBCM of PMAA-FeOX nanoparticles is a possible solution to reducing MRI interference from the coupling bath without increasing the risk of prefocal cavitation.
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Affiliation(s)
- Connor Edsall
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Austin Fergusson
- Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Richey M Davis
- Department of Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Craig H Meyer
- Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Steven P Allen
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT, USA
| | - Eli Vlaisavljevich
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA; ICTAS Center for Engineered Health, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.
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Yan X, Allen S, Lu M, Moore D, Meyer CH, Grissom WA. Dark band artifact in transcranial MR-guided focused ultrasound: Mechanism and mitigation with passive crossed wire antennas. Magn Reson Imaging 2023; 103:169-178. [PMID: 37543175 PMCID: PMC10528914 DOI: 10.1016/j.mri.2023.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/27/2023] [Accepted: 07/31/2023] [Indexed: 08/07/2023]
Abstract
Current FDA-approved transcranial MR-guided focused ultrasound (tcMRgFUS) transducers cause a curved dark band in 3 T brain images that runs through midbrain targets of ablative treatments for essential tremor and other applications, and signal is reduced by at least 25% elsewhere in the brain. This limits the set of scans that can be performed to guide and assess the effects of treatment. An electromagnetic simulation study was performed to elucidate the mechanisms causing the dark band. Based on the results, a pair of passive antennas in a "propeller-beanie" configuration were designed to manipulate the reflected waves to avoid signal cancellation within the brain. The antennas were optimized and validated with in-vivo experiments and hydrophone measurements. The simulation study revealed that the dark band is caused by RF waves reflected from the transducer's ground plane, which cancel with incoming waves from the scanner's body coil. The passive antennas shifted the dark band out of the brain and increased transmit efficiency in the center of brain 2.3 times while improving field homogeneity by 50%. They also increased receive sensitivity and SNR in anatomic and temperature imaging. They caused no detectable distortion in hydrophone-measured focal pressure profiles. The conductive ground planes and coupling media used in tcMRgFUS and other piezoelectric FUS transducers interact with a 3 T scanner's RF fields to reduce transmit efficiency and SNR. For tcMRgFUS scenario, "propeller beanie" passive reflecting antennas alleviated these effects. This could make a broader set of imaging sequences available to guide tcMRgFUS treatment.
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Affiliation(s)
- Xinqiang Yan
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Electrical and Computer Engineering, Vanderbilt University, Nashville, TN 37232, USA.
| | - Steven Allen
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Ming Lu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - David Moore
- Focused Ultrasound Foundation, Charlottesville, VA, USA
| | - Craig H Meyer
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - William A Grissom
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Electrical and Computer Engineering, Vanderbilt University, Nashville, TN 37232, USA; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, USA
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Allen SP, Fergusson A, Edsall C, Chen S, Moore D, Vlaisavljevich E, Davis RM, Meyer CH. Iron-based coupling media for MRI-guided ultrasound surgery. Med Phys 2022; 49:7373-7383. [PMID: 36156266 PMCID: PMC9946126 DOI: 10.1002/mp.15979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/17/2022] [Accepted: 08/31/2022] [Indexed: 12/27/2022] Open
Abstract
PURPOSE In this study, we examine the effects of a recently developed, iron-based coupling medium (IBCM) on guidance magnetic resonance (MR) scans during transcranial, magnetic-resonance-guided, focused ultrasound surgery (tMRgFUS) procedures. More specifically, this study tests the hypotheses that the use of the IBCM will (a) not adversely affect image quality, (b) remove aliasing from small field-of-view scans, and (c) decouple image quality from the motion state of the coupling fluid. METHODS An IBCM, whose chemical synthesis and characterization are reported elsewhere, was used as a coupling medium during tMRgFUS procedures on gel phantoms. Guidance magnetization-prepared rapid-gradient-echo (MP-RAGE), TSE, and GRE scans were acquired with fields of view of 28 and 18 cm. Experiments were repeated with the IBCM in several distinct flow states. GRE scans were used to estimate temperature time courses as a gel target was insonated. IBCM performance was measured by computing (i) the root mean square difference (RMSD) of TSE and GRE pixel values acquired using water and the IBCM, relative to the use of water; (ii) through-time temperature uncertainty for GRE scans; and (iii) Bland-Altman analysis of the temperature time courses. Finally, guidance TSE and GRE scans of a human volunteer were acquired during a separate sham tMRgFUS procedure. As a control, all experiments were repeated using a water coupling medium. RESULTS Use of the IBCM reduced RMSD in TSE scans by a factor of 4 or more for all fields of view and nonstationary motion states, but did not reduce RMSD estimates in MP-RAGE scans. With the coupling media in a stationary state, the IBCM altered estimates of temperature uncertainty relative to the use of water by less than 0.2°C. However, with a high flow state, the IBCM reduced temperature uncertainties by the statistically significant amounts (at the 0.01 level) of 0.5°C (28 cm field of view) and 5°C (18 cm field of view). Bland-Altman analyses found a 0.1°C ± 0.5°C difference between temperature estimates acquired using water and the IBCM as coupling media. Finally, scans of a human volunteer using the IBCM indicate more conspicuous grey/white matter contrast, a reduction in aliasing, and a less than 0.2°C change in temperature uncertainty. CONCLUSIONS The use of an IBCM during tMRgFUS procedures does not adversely affect image quality for TSE and GRE scans, can decouple image quality from the motion state of the coupling fluid, and can remove aliasing from scans where the field of view is set to be much smaller than the spatial extent of the coupling fluid.
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Affiliation(s)
- Steven P Allen
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, Utah, USA
| | - Austin Fergusson
- Graduate Program in Translational Biology, Medicine and Health Virginia Tech, Blacksburg, Virginia, USA
| | - Connor Edsall
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia, USA
| | - Sheng Chen
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - David Moore
- The Focused Ultrasound Foundation, Charlottesville, Virginia, USA
| | - Eli Vlaisavljevich
- Graduate Program in Translational Biology, Medicine and Health Virginia Tech, Blacksburg, Virginia, USA
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, Virginia, USA
| | - Richey M Davis
- Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia, USA
| | - Craig H Meyer
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, USA
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Boehm C, Goeger-Neff M, Mulder HT, Zilles B, Lindner LH, van Rhoon GC, Karampinos DC, Wu M. Susceptibility artifact correction in MR thermometry for monitoring of mild radiofrequency hyperthermia using total field inversion. Magn Reson Med 2022; 88:120-132. [PMID: 35313384 DOI: 10.1002/mrm.29191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 12/28/2022]
Abstract
PURPOSE MR temperature monitoring of mild radiofrequency hyperthermia (RF-HT) of cancer exploits the linear resonance frequency shift of water with temperature. Motion-induced susceptibility distribution changes cause artifacts that we correct here using the total field inversion (TFI) approach. METHODS The performance of TFI was compared to two background field removal (BFR) methods: Laplacian boundary value (LBV) and projection onto dipole fields (PDF). Data sets with spatial susceptibility change and B 0 -drift were simulated, phantom heating experiments were performed, four volunteer data sets at thermoneutral conditions as well as data from one cervical cancer, two sarcoma, and one seroma patients undergoing mild RF-HT were corrected using the proposed methods. RESULTS Simulations and phantom heating experiments revealed that using BFR or TFI preserves temperature-induced phase change, while removing susceptibility artifacts and B 0 -drift. TFI resulted in the least cumulative error for all four volunteers. Temperature probe information from four patient data sets were best depicted by TFI-corrected data in terms of accuracy and precision. TFI also performed best in case of the sarcoma treatment without temperature probe. CONCLUSION TFI outperforms previously suggested BFR methods in terms of accuracy and robustness. While PDF consistently overestimates susceptibility contribution, and LBV removes valuable pixel information, TFI is more robust and leads to more accurate temperature estimations.
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Affiliation(s)
- Christof Boehm
- Department of Diagnostic and Interventional Radiology, School of Medicine, Technical University of Munich, Munich, Germany
| | | | | | - Benjamin Zilles
- Department of Medicine III, University Hospital, LMU Munich, Munich, Germany
| | - Lars H Lindner
- Department of Medicine III, University Hospital, LMU Munich, Munich, Germany
| | | | - Dimitrios C Karampinos
- Department of Diagnostic and Interventional Radiology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Mingming Wu
- Department of Diagnostic and Interventional Radiology, School of Medicine, Technical University of Munich, Munich, Germany
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Józefczak A, Kaczmarek K, Bielas R. Magnetic mediators for ultrasound theranostics. Theranostics 2021; 11:10091-10113. [PMID: 34815806 PMCID: PMC8581415 DOI: 10.7150/thno.62218] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 10/02/2021] [Indexed: 12/11/2022] Open
Abstract
The theranostics paradigm is based on the concept of combining therapeutic and diagnostic modalities into one platform to improve the effectiveness of treatment. Combinations of multiple modalities provide numerous medical advantages and are enabled by nano- and micron-sized mediators. Here we review recent advancements in the field of ultrasound theranostics and the use of magnetic materials as mediators. Several subdisciplines are described in detail, including controlled drug delivery and release, ultrasound hyperthermia, magneto-ultrasonic heating, sonodynamic therapy, magnetoacoustic imaging, ultrasonic wave generation by magnetic fields, and ultrasound tomography. The continuous progress and improvement in theranostic materials, methods, and physical computing models have created undeniable possibilities for the development of new approaches. We discuss the prospects of ultrasound theranostics and possible expansions of other studies to the theranostic context.
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Affiliation(s)
- Arkadiusz Józefczak
- Chair of Acoustics, Faculty of Physics, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
| | - Katarzyna Kaczmarek
- Department of Biomedical Engineering, Faculty of Engineering, University of Strathclyde, Wolfson Centre, 106 Rottenrow, Glasgow, United Kingdom
| | - Rafał Bielas
- Chair of Acoustics, Faculty of Physics, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
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Allen SP, Prada F, Xu Z, Gatesman J, Feng X, Sporkin H, Gilbo Y, DeCleene S, Pauly KB, Meyer CH. A preclinical study of diffusion-weighted MRI contrast as an early indicator of thermal ablation. Magn Reson Med 2020; 85:2145-2159. [PMID: 33174639 DOI: 10.1002/mrm.28537] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 08/28/2020] [Accepted: 09/09/2020] [Indexed: 12/28/2022]
Abstract
PURPOSE Intraoperative T2 -weighted (T2-w) imaging unreliably captures image contrast specific to thermal ablation after transcranial MR-guided focused ultrasound surgery, impeding dynamic imaging feedback. Using a porcine thalamotomy model, we test the unproven hypothesis that intraoperative DWI can improve dynamic feedback by detecting lesioning within 30 minutes of transcranial MR-guided focused ultrasound surgery. METHODS Twenty-five thermal lesions were formed in six porcine models using a clinical transcranial MR-guided focused ultrasound surgery system. A novel diffusion-weighted pulse sequence monitored the formation of T2-w and diffusion-weighted lesion contrast after ablation. Using postoperative T2-w contrast to indicate lesioning, apparent intraoperative image contrasts and diffusion coefficients at each lesion site were computed as a function of time after ablation, observed peak temperature, and observed thermal dose. Lesion sizes segmented from imaging and thermometry were compared. Image reviewers estimated the time to emergence of lesion contrast. Intraoperative image contrasts were analyzed using receiver operator curves. RESULTS On average, the apparent diffusion coefficient at lesioned sites decreased within 5 minutes after ablation relative to control sites. In-plane lesion areas on intraoperative DWI varied from postoperative T2-w MRI and MR thermometry by 9.6 ± 9.7 mm2 and - 4.0 ± 7.1 mm2 , respectively. The 0.25, 0.5, and 0.75 quantiles of the earliest times of observed T2-w and diffusion-weighted lesion contrast were 10.7, 21.0, and 27.8 minutes and 3.7, 8.6, and 11.8 minutes, respectively. The T2-w and diffusion-weighted contrasts and apparent diffusion coefficient values produced areas under the receiver operator curve of 0.66, 0.80, and 0.74, respectively. CONCLUSION Intraoperative DWI can detect MR-guided focused ultrasound surgery lesion formation in the brain within several minutes after treatment.
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Affiliation(s)
- Steven P Allen
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Francesco Prada
- Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy.,Department of Neurosurgery, University of Virginia, Charlottesville, Virginia, USA
| | - Zhiyuan Xu
- Department of Neurosurgery, University of Virginia, Charlottesville, Virginia, USA
| | - Jeremy Gatesman
- Center for Comparative Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Xue Feng
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Helen Sporkin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Yekaterina Gilbo
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Sydney DeCleene
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Kim Butts Pauly
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Craig H Meyer
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA.,Department of Radiology, University of Virginia, Charlottesville, Virginia, USA
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Payne A, Minalga E, Merrill R, Parker DL, Hadley JR. Technical Note: Effect of transducer position and ground plane configuration on image quality in MR-guided focused ultrasound therapies. Med Phys 2020; 47:2350-2355. [PMID: 32170866 PMCID: PMC7802121 DOI: 10.1002/mp.14138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 12/21/2022] Open
Abstract
PURPOSE To evaluate the effect of a focused ultrasound transducer position and ground plane configuration on magnetic resonance image quality. METHODS The effect of transducer position with respect to the MRI B0 field and the radiofrequency receive coils was evaluated in a breast-specific MRgFUS system with an integrated RF phased-array coil. Image signal-to-noise ratio was evaluated at different transducer locations. The effect of ultrasound transducer ground plane configuration was evaluated using a replica transducer with 12 ground plane configurations. All evaluations were performed at 3 Tesla. RESULTS Both transducer position and ground plane configuration were found to have a considerable effect on overall image SNR. A 67% increase in SNR was achieved by positioning the transducer face perpendicular to the B0 field. A 25% increase in SNR was achieved by segmenting the replica transducer ground plane from one continuous plane to nine individual segments. CONCLUSIONS Advances in focused ultrasound hardware allow for integrated radiofrequency MRI coils as well as adjustable transducer positioning. The placement of the ultrasound transducer with respect to both the magnetic field and RF coils can have a considerable effect on image SNR and the resulting MR images that are used for MR-guided focused ultrasound treatment planning, monitoring and assessment.
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Affiliation(s)
- Allison Payne
- Utah Center for Advanced Imaging Research, Dept. of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA 84108
| | - Emilee Minalga
- Utah Center for Advanced Imaging Research, Dept. of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA 84108
| | - Robb Merrill
- Utah Center for Advanced Imaging Research, Dept. of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA 84108
| | - Dennis L. Parker
- Utah Center for Advanced Imaging Research, Dept. of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA 84108
| | - J. Rock Hadley
- Utah Center for Advanced Imaging Research, Dept. of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah, USA 84108
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Sumser K, Bellizzi GG, van Rhoon GC, Paulides MM. The Potential of Adjusting Water Bolus Liquid Properties for Economic and Precise MR Thermometry Guided Radiofrequency Hyperthermia. SENSORS 2020; 20:s20102946. [PMID: 32456027 PMCID: PMC7288164 DOI: 10.3390/s20102946] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 05/14/2020] [Accepted: 05/21/2020] [Indexed: 11/23/2022]
Abstract
The potential of MR thermometry (MRT) fostered the development of MRI compatible radiofrequency (RF) hyperthermia devices. Such device integration creates major technological challenges and a crucial point for image quality is the water bolus (WB). The WB is located between the patient body and external sources to both couple electromagnetic energy and to cool the patient skin. However, the WB causes MRT errors and unnecessarily large field of view. In this work, we studied making the WB MRI transparent by an optimal concentration of compounds capable of modifying T2* relaxation without an impact on the efficiency of RF heating. Three different T2* reducing compounds were investigated, namely CuSO4, MnCl2, and Fe3O4. First, electromagnetic properties and T2* relaxation rates at 1.5 T were measured. Next, through multi-physics simulations, the predicted effect on the RF-power deposition pattern was evaluated and MRT precision was experimentally assessed. Our results identified 5 mM Fe3O4 solution as optimal since it does not alter the RF-power level needed and improved MRT precision from 0.39 °C to 0.09 °C. MnCl2 showed a similar MRT improvement, but caused unacceptable RF-power losses. We conclude that adding Fe3O4 has significant potential to improve RF hyperthermia treatment monitoring under MR guidance.
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Affiliation(s)
- Kemal Sumser
- Department of Radiation Oncology, Erasmus MC—Cancer Institute, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (G.G.B.); (G.C.v.R.); (M.M.P.)
- Correspondence:
| | - Gennaro G. Bellizzi
- Department of Radiation Oncology, Erasmus MC—Cancer Institute, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (G.G.B.); (G.C.v.R.); (M.M.P.)
| | - Gerard C. van Rhoon
- Department of Radiation Oncology, Erasmus MC—Cancer Institute, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (G.G.B.); (G.C.v.R.); (M.M.P.)
| | - Margarethus M. Paulides
- Department of Radiation Oncology, Erasmus MC—Cancer Institute, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (G.G.B.); (G.C.v.R.); (M.M.P.)
- EM4C&C Laboratory, Center for Care & Cure Technology Eindhoven (C3Te), Department of Electrical Engineering, Eindhoven University of Technology, 5612 AZ Eindhoven, The Netherlands
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