A transmit/receive system for magnetic field monitoring of in vivo MRI

Magnetic Resonance Imaging (MRI) observes tissue water in the presence of a magnetic field gradient to study morphological changes such as tissue volume loss and signal hyperintensities in human disease. These changes are mostly non-specific and do not appear to be correlated with the range of severity of a certain disease. In contrast, Magnetic Resonance Spectroscopy (MRS), which measures many different chemicals and tissue metabolites in the millimolar concentration range in the absence of a magnetic field gradient, has been shown to reveal characteristic metabolite patterns which are often correlated with the severity of a disease. In-vivo MRS studies are performed on widely available MRI scanners without any “sample preparation” or invasive procedures and are therefore widely used in clinical research. Hydrogen (H) MRS and MR Spectroscopic Imaging (MRSI, conceptionally a combination of MRI and MRS) measure N-acetylaspartate (a putative marker of neurons), creatine-containing metabolites (involved in energy processes in the cell), choline-containing metabolites (involved in membrane metabolism and, possibly, inflammatory processes),

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Intense Static Magnetic Field Induced Bone Growth in Vivo

Electromagnetic Biology and Medicine ◽

10.3109/15368378409035968 ◽

1984 ◽

Vol 3 (1) ◽

pp. 223-234

Author(s):

Frank Papatheofanis ◽

Bill Fapatheofanls ◽

Robert Ray

Keyword(s):

Magnetic Field ◽

Static Magnetic Field ◽

Bone Growth

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Magnetic Nanodiscs—A New Promising Tool for Microsurgery of Malignant Neoplasms

Nanomaterials ◽

10.3390/nano11061459 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1459

Author(s):

Tatiana N. Zamay ◽

Vladimir S. Prokopenko ◽

Sergey S. Zamay ◽

Kirill A. Lukyanenko ◽

Olga S. Kolovskaya ◽

...

Keyword(s):

Magnetic Field ◽

Remote Control ◽

Tumor Cells ◽

Biological Effects ◽

Malignant Neoplasms ◽

Rotating Magnetic Fields ◽

Magnetic Structures ◽

Promising Tool

Magnetomechanical therapy is one of the most perspective directions in tumor microsurgery. According to the analysis of recent publications, it can be concluded that a nanoscalpel could become an instrument sufficient for cancer microsurgery. It should possess the following properties: (1) nano- or microsized; (2) affinity and specificity to the targets on tumor cells; (3) remote control. This nano- or microscalpel should include at least two components: (1) a physical nanostructure (particle, disc, plates) with the ability to transform the magnetic moment to mechanical torque; (2) a ligand—a molecule (antibody, aptamer, etc.) allowing the scalpel precisely target tumor cells. Literature analysis revealed that the most suitable nanoscalpel structures are anisotropic, magnetic micro- or nanodiscs with high-saturation magnetization and the absence of remanence, facilitating scalpel remote control via the magnetic field. Additionally, anisotropy enhances the transmigration of the discs to the tumor. To date, four types of magnetic microdiscs have been used for tumor destruction: synthetic antiferromagnetic P-SAF (perpendicular) and SAF (in-plane), vortex Py, and three-layer non-magnetic–ferromagnet–non-magnetic systems with flat quasi-dipole magnetic structures. In the current review, we discuss the biological effects of magnetic discs, the mechanisms of action, and the toxicity in alternating or rotating magnetic fields in vitro and in vivo. Based on the experimental data presented in the literature, we conclude that the targeted and remotely controlled magnetic field nanoscalpel is an effective and safe instrument for cancer therapy or theranostics.

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Magnetic targeting with superparamagnetic iron oxide nanoparticles for in vivo glioma

Nanotechnology Reviews ◽

10.1515/ntrev-2016-0101 ◽

2017 ◽

Vol 6 (5) ◽

pp. 449-472 ◽

Cited By ~ 4

Author(s):

Marina Fontes de Paula Aguiar ◽

Javier Bustamante Mamani ◽

Taylla Klei Felix ◽

Rafael Ferreira dos Reis ◽

Helio Rodrigues da Silva ◽

...

Keyword(s):

Magnetic Field ◽

Iron Oxide ◽

Iron Oxide Nanoparticles ◽

Superparamagnetic Iron Oxide ◽

Superparamagnetic Iron Oxide Nanoparticles ◽

Process Efficiency ◽

Cochrane Library ◽

Oxide Nanoparticles ◽

Magnetic Targeting

AbstractThe purpose of this study was to review the use of the magnetic targeting technique, characterized by magnetic driving compounds based on superparamagnetic iron oxide nanoparticles (SPIONs), as drug delivery for a specific brain locus in gliomas. We reviewed a process mediated by the application of an external static magnetic field for targeting SPIONs in gliomas. A search of PubMed, Cochrane Library, Scopus, and Web of Science databases identified 228 studies, 23 of which were selected based on inclusion criteria and predetermined exclusion criteria. The articles were analyzed by physicochemical characteristics of SPIONs used, cell types used for tumor induction, characteristics of experimental glioma models, magnetic targeting technical parameters, and analysis method of process efficiency. The study shows the highlights and importance of magnetic targeting to optimize the magnetic targeting process as a therapeutic strategy for gliomas. Regardless of the intensity of the patterned magnetic field, the time of application of the field, and nanoparticle used (commercial or synthesized), all studies showed a vast advantage in the use of magnetic targeting, either alone or in combination with other techniques, for optimized glioma therapy. Therefore, this review elucidates the preclinical and therapeutic applications of magnetic targeting in glioma, an innovative nanobiotechnological method.

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Effect of Magnetic Field on Bone Healing around Endosseous Implants – An In-vivo Study

JOURNAL FOR CLINICAL AND DIAGNOSTIC RESEARCH ◽

10.7860/jcdr/2016/21509.8666 ◽

2016 ◽

Cited By ~ 1

Author(s):

Mahalakshmi Gujjalapudi

Keyword(s):

Magnetic Field ◽

Bone Healing ◽

In Vivo Study ◽

Endosseous Implants

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A newly designed and constructed 20 kHz magnetic field exposure facility for in vivo study

Bioelectromagnetics ◽

10.1002/bem.20439 ◽

2009 ◽

Vol 30 (1) ◽

pp. 36-44 ◽

Cited By ~ 7

Author(s):

Tsukasa Shigemitsu ◽

Tadashi Negishi ◽

Keita Yamazaki ◽

Yoshinobu Kawahara ◽

Akira Haga ◽

...

Keyword(s):

Magnetic Field ◽

In Vivo Study ◽

Field Exposure ◽

Magnetic Field Exposure

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A THREE-PHASE INDUCTIVE SENSOR FOR IN VIVO MEASUREMENT OF ELECTRICAL ANISOTROPY OF BIOLOGICAL TISSUES

Contemporary Materials ◽

10.7251/comen1401001k ◽

2014 ◽

Vol 5 (1) ◽

Author(s):

Yukio Kosugi ◽

Tadashi Takemae ◽

Hiroki Takeshima ◽

Atsushi Kudo ◽

Kazuyuki Kojima ◽

...

Keyword(s):

Magnetic Field ◽

Electrical Conductivity ◽

High Frequency ◽

Reference Signal ◽

Biological Tissues ◽

Electrical Anisotropy ◽

Conductivity Anisotropy ◽

In Vivo Measurement ◽

Surgical Operations

Biological tissue will have anisotropy in electrical conductivity, due to the orientation of muscular fibers or neural axons as well as the distribution of large size blood vessels. Thus, the in vivo measurement of electrical conductivity anisotropy can be used to detect deep-seated vessels in large organs such as the liver during surgeries. For diagnostic applications, decrease of anisotropy may indicate the existence of cancer in anisotropic tissues such as the white matter of the brain or the mammary gland in the breast. In this paper, we will introduce a new tri-phase induction method to drive rotating high-frequency electrical current in the tissue for the measurement of electrical conductivity anisotropy. In the measurement, three electromagnets are symmetrically placed on the tissue surface and driven by high-frequency alternative currents of 0 kHz, modulated with 1 kHz 3-phase signals. In the center area of three magnets, magnetic fields are superimposed to produce a rotating induction current. This current produces electrical potentials among circularly arranged electrodes to be used to find the conductivity in each direction determined by the electrode pairs. To find the horizontal and vertical signal components, the measured potentials are amplified by a 2ch lock-in amplifier phase-locked with the 1 kHz reference signal. The superimposed current in the tissue was typically 45 micro Amperes when we applied 150 micro Tesla of magnetic field. We showed the validity of our method by conducting in vitro measurements with respect to artificially formed anisotropic materials and preliminary in vivo measurements on the pig’s liver. Compared to diffusion tensor MRI method, our anisotropy sensor is compact and advantageous for use during surgical operations because our method does not require strong magnetic field that may disturb ongoing surgical operations.

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