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Pantke D, Mueller F, Reinartz S, Philipps J, Mohammadali Dadfar S, Peters M, Franke J, Schrank F, Kiessling F, Schulz V. Frequency-selective signal enhancement by a passive dual coil resonator for magnetic particle imaging. Phys Med Biol 2022; 67. [PMID: 35472698 DOI: 10.1088/1361-6560/ac6a9f] [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: 10/18/2021] [Accepted: 04/26/2022] [Indexed: 11/12/2022]
Abstract
Objective.Magnetic particle imaging (MPI) visualizes the spatial distribution of magnetic nanoparticles. MPI already provides excellent temporal and good spatial resolution, however, to achieve translation into clinics, further advances in the fields of sensitivity, image reconstruction and tracer performance are needed. In this work, we propose a novel concept to enhance the MPI signal and image resolution by a purely passive receive coil insert for a preclinical MPI system.Approach.The passive dual coil resonator (pDCR) provides frequency-selective signal enhancement. This is enabled by the adaptable resonance frequency of the pDCR network, which is galvanically isolated from the MPI system and composed of two coaxial solenoids connected via a capacitor. The pDCR aims to enhance frequency components related to high mixing orders, which are crucial to achieve high spatial resolution.Main Results.In this study, system matrix measurements and image acquisitions of a resolution phantom are carried out to evaluate the performance of the pDCR compared to the integrated receive unit of the preclinical MPI and a dedicated rat-sized receive coil. Frequency-selective signal increase and spatial resolution enhancement are demonstrated.Significance.Common dedicated receive coils come along with noise-matched receive networks, which makes them costly and difficult to reproduce. The presented pDCR is a purely passive coil insert that gets along without any additional receive electronics. Therefore, it is cost-efficient, easy-to-handle and adaptable to other MPI scanners and potentially other applications providing the basis for a new breed of passive MPI receiver systems.
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Affiliation(s)
- Dennis Pantke
- Department of Physics of Molecular Imaging, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Florian Mueller
- Department of Physics of Molecular Imaging, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Sebastian Reinartz
- Department of Diagnostic and Interventional Radiology, Uniklinik RWTH Aachen, Aachen, Germany
| | - Jonas Philipps
- Department of Physics of Molecular Imaging, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Seyed Mohammadali Dadfar
- Institute for Experimental Molecular Imaging, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Maximilian Peters
- Department of Physics of Molecular Imaging, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Jochen Franke
- Department of Physics of Molecular Imaging, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany.,Bruker BioSpin MRI GmbH, Preclinical Imaging Division, Ettlingen, Germany
| | - Franziska Schrank
- Department of Physics of Molecular Imaging, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany
| | - Fabian Kiessling
- Institute for Experimental Molecular Imaging, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Volkmar Schulz
- Department of Physics of Molecular Imaging, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany.,Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany.,III. Physikalisches Institut B, RWTH Aachen University, Aachen, Germany
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Pagan J, McDonough C, Vo T, Tonyushkin A. Single-Sided Magnetic Particle Imaging Device with Field-Free-Line Geometry for in-vivo Imaging Applications. IEEE TRANSACTIONS ON MAGNETICS 2021; 57:5300105. [PMID: 33746245 PMCID: PMC7978233 DOI: 10.1109/tmag.2020.3008596] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Magnetic Particle Imaging (MPI) has shown great promise to surpass existing in vivo imaging modalities in some clinical applications. However, one of the challenges to MPI being translated into clinical practice has been the ability to scale up the selection field coils to surround a human body while being able to generate and drive a sufficiently strong magnetic field gradient. These requirements impose safety concerns as well as prohibitively high-power consumption in devices with large cylindrical volume. Therefore, we consider an alternative approach such as a single-sided topology, in which all the hardware is located on one side of the imaging volume accommodating larger subjects. Moreover, different from the previously implemented field-free point single-sided scanners, we realized a field-free line geometry providing, in principle, factor of ten higher signal and benefiting from a more robust back-projection image reconstruction technique. In this work, we present and characterize a first prototype of a single-sided MPI device with field-free-line geometry suited for in-vivo imaging of small animals as well as regions of interest in humans.
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Affiliation(s)
- Jason Pagan
- Physics Department, University of Massachusetts Boston, Boston, MA 02125 USA
| | - Chris McDonough
- Physics Department, University of Massachusetts Boston, Boston, MA 02125 USA
| | - Triet Vo
- Engineering Department, University of Massachusetts Boston, Boston, MA 02125 USA
| | - Alexey Tonyushkin
- Physics Department, University of Massachusetts Boston, Boston, MA 02125 USA
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Santrac N, Markovic I, Medic Milijic N, Goran M, Buta M, Djurisic I, Dzodic R. Sentinel lymph node biopsy in medullary thyroid microcarcinomas. Endocr J 2020; 67:295-304. [PMID: 31801918 DOI: 10.1507/endocrj.ej19-0409] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The aim of this prospective study was to analyze accuracy of sentinel lymph node biopsy with methylene blue dye for intraoperative detection of lateral metastases in clinically N0M0 medullary microcarcinomas with calcitonin <1,000 pg/mL and selection of true-positive patients for one-time therapeutic lateral dissection. In addition to total thyroidectomy and central neck dissection, all patients had bilateral sentinel biopsy of jugulo-carotid regions after methylene blue injection to decide upon necessity for lateral dissection. If sentinels were benign on frozen section, additional non-sentinels were extirpated, with no further lateral dissection. If sentinels were malignant, one-time lateral dissection was performed. 20 patients were included in this study. Hereditary disease form was observed in 3/20 (15%) of patients with RET proto-oncogene mutation C634F; remaining 17/20 (85%) were negative for germline mutations. There were no allergic reactions to methylene blue and identification rate of sentinels was 100%. In total, 2/20 (10%) cN0 patients had lymphonodal metastases, thus were reclassified as pN1b. Remaining 18/20 (90%) were classified pN0 based on standard pathohistology. Frozen section findings on sentinels were 100% match with standard pathohistology, and there were no skip metastases in lateral compartments. Sensitivity, specificity and accuracy of sentinel biopsy method with methylene dye and frozen section were 100%. Dzodic's sentinel lymph node biopsy method can be used for intraoperative assessment of lateral compartments and optimization of initial surgery of medullary microcarcinomas with calcitonin <1,000 pg/mL. This way, cN0 patients with sentinel metastases can receive one-time lateral dissection, and those without benefit from less extensive surgery.
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Affiliation(s)
- Nada Santrac
- Surgical Oncology Clinic, Institute for Oncology and Radiology of Serbia, Belgrade, 11000, Serbia
| | - Ivan Markovic
- Surgical Oncology Clinic, Institute for Oncology and Radiology of Serbia, Belgrade, 11000, Serbia
- School of Medicine, University of Belgrade, Belgrade, 11000, Serbia
| | - Natasa Medic Milijic
- Department of Pathology, Institute for Oncology and Radiology of Serbia, Belgrade, 11000, Serbia
| | - Merima Goran
- Surgical Oncology Clinic, Institute for Oncology and Radiology of Serbia, Belgrade, 11000, Serbia
- School of Medicine, University of Belgrade, Belgrade, 11000, Serbia
| | - Marko Buta
- Surgical Oncology Clinic, Institute for Oncology and Radiology of Serbia, Belgrade, 11000, Serbia
- School of Medicine, University of Belgrade, Belgrade, 11000, Serbia
| | - Igor Djurisic
- Surgical Oncology Clinic, Institute for Oncology and Radiology of Serbia, Belgrade, 11000, Serbia
| | - Radan Dzodic
- Surgical Oncology Clinic, Institute for Oncology and Radiology of Serbia, Belgrade, 11000, Serbia
- School of Medicine, University of Belgrade, Belgrade, 11000, Serbia
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Duschka RL, Haegele J, Panagiotopoulos N, Wojtczyk H, Barkhausen J, Vogt FM, Buzug TM, Lüdtke-Buzug K. Fundamentals and Potential of Magnetic Particle Imaging. CURRENT CARDIOVASCULAR IMAGING REPORTS 2013. [DOI: 10.1007/s12410-013-9217-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Buzug TM, Bringout G, Erbe M, Gräfe K, Graeser M, Grüttner M, Halkola A, Sattel TF, Tenner W, Wojtczyk H, Haegele J, Vogt FM, Barkhausen J, Lüdtke-Buzug K. Magnetic particle imaging: introduction to imaging and hardware realization. Z Med Phys 2012; 22:323-34. [PMID: 22909418 DOI: 10.1016/j.zemedi.2012.07.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 07/30/2012] [Accepted: 07/30/2012] [Indexed: 12/18/2022]
Abstract
Magnetic Particle Imaging (MPI) is a recently invented tomographic imaging method that quantitatively measures the spatial distribution of a tracer based on magnetic nanoparticles. The new modality promises a high sensitivity and high spatial as well as temporal resolution. There is a high potential of MPI to improve interventional and image-guided surgical procedures because, today, established medical imaging modalities typically excel in only one or two of these important imaging properties. MPI makes use of the non-linear magnetization characteristics of the magnetic nanoparticles. For this purpose, two magnetic fields are created and superimposed, a static selection field and an oscillatory drive field. If superparamagnetic iron-oxide nanoparticles (SPIOs) are subjected to the oscillatory magnetic field, the particles will react with a non-linear magnetization response, which can be measured with an appropriate pick-up coil arrangement. Due to the non-linearity of the particle magnetization, the received signal consists of the fundamental excitation frequency as well as of harmonics. After separation of the fundamental signal, the nanoparticle concentration can be reconstructed quantitatively based on the harmonics. The spatial coding is realized with the static selection field that produces a field-free point, which is moved through the field of view by the drive fields. This article focuses on the frequency-based image reconstruction approach and the corresponding imaging devices while alternative concepts like x-space MPI and field-free line imaging are described as well. The status quo in hardware realization is summarized in an overview of MPI scanners.
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Affiliation(s)
- Thorsten M Buzug
- Institute of Medical Engineering, University of Lübeck, Lübeck, Germany.
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