MNP-Enhanced Microwave Medical Imaging by Means of Pseudo-Noise Sensing
Magnetic nanoparticles have been investigated for microwave imaging over the last decade. The use of functionalized magnetic nanoparticles, which are able to accumulate selectively within tumorous tissue, can increase the diagnostic reliability. This paper deals with the detecting and imaging of mag...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-10-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/21/19/6613 |
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| author | Sebastian Ley Jürgen Sachs Bernd Faenger Ingrid Hilger Marko Helbig |
| author_facet | Sebastian Ley Jürgen Sachs Bernd Faenger Ingrid Hilger Marko Helbig |
| author_sort | Sebastian Ley |
| collection | DOAJ |
| description | Magnetic nanoparticles have been investigated for microwave imaging over the last decade. The use of functionalized magnetic nanoparticles, which are able to accumulate selectively within tumorous tissue, can increase the diagnostic reliability. This paper deals with the detecting and imaging of magnetic nanoparticles by means of ultra-wideband microwave sensing via pseudo-noise technology. The investigations were based on phantom measurements. In the first experiment, we analyzed the detectability of magnetic nanoparticles depending on the magnetic field intensity of the polarizing magnetic field, as well as the viscosity of the target and the surrounding medium in which the particles were embedded, respectively. The results show a nonlinear behavior of the magnetic nanoparticle response depending on the magnetic field intensity for magnetic nanoparticles diluted in distilled water and for magnetic nanoparticles embedded in a solid medium. Furthermore, the maximum amplitude of the magnetic nanoparticles responses varies for the different surrounding materials of the magnetic nanoparticles. In the second experiment, we investigated the influence of the target position on the three-dimensional imaging of the magnetic nanoparticles in a realistic measurement setup for breast cancer imaging. The results show that the magnetic nanoparticles can be detected successfully. However, the intensity of the particles in the image depends on its position due to the path-dependent attenuation, the inhomogeneous microwave illumination of the breast, and the inhomogeneity of the magnetic field. Regarding the last point, we present an approach to compensate for the inhomogeneity of the magnetic field by computing a position-dependent correction factor based on the measured magnetic field intensity and the magnetic susceptibility of the magnetic particles. Moreover, the results indicate an influence of the polarizing magnetic field on the measured ultra-wideband signals even without magnetic nanoparticles. Such a disturbing influence of the polarizing magnetic field on the measurements should be reduced for a robust magnetic nanoparticles detection. Therefore, we analyzed the two-state (ON/OFF) and the sinusoidal modulation of the external magnetic field concerning the detectability of the magnetic nanoparticles with respect to these spurious effects, as well as their practical application. |
| first_indexed | 2024-03-10T06:50:53Z |
| format | Article |
| id | doaj.art-26418a3ac33a4b12867eb1c07f7c670c |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-10T06:50:53Z |
| publishDate | 2021-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-26418a3ac33a4b12867eb1c07f7c670c2023-11-22T16:48:45ZengMDPI AGSensors1424-82202021-10-012119661310.3390/s21196613MNP-Enhanced Microwave Medical Imaging by Means of Pseudo-Noise SensingSebastian Ley0Jürgen Sachs1Bernd Faenger2Ingrid Hilger3Marko Helbig4Biosignal Processing Group, Technische Universität Ilmenau, 98693 Ilmenau, GermanyElectronic Measurements and Signal Processing Group, Technische Universität Ilmenau, 98693 Ilmenau, GermanyInstitute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich Schiller University Jena, 07747 Jena, GermanyInstitute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich Schiller University Jena, 07747 Jena, GermanyBiosignal Processing Group, Technische Universität Ilmenau, 98693 Ilmenau, GermanyMagnetic nanoparticles have been investigated for microwave imaging over the last decade. The use of functionalized magnetic nanoparticles, which are able to accumulate selectively within tumorous tissue, can increase the diagnostic reliability. This paper deals with the detecting and imaging of magnetic nanoparticles by means of ultra-wideband microwave sensing via pseudo-noise technology. The investigations were based on phantom measurements. In the first experiment, we analyzed the detectability of magnetic nanoparticles depending on the magnetic field intensity of the polarizing magnetic field, as well as the viscosity of the target and the surrounding medium in which the particles were embedded, respectively. The results show a nonlinear behavior of the magnetic nanoparticle response depending on the magnetic field intensity for magnetic nanoparticles diluted in distilled water and for magnetic nanoparticles embedded in a solid medium. Furthermore, the maximum amplitude of the magnetic nanoparticles responses varies for the different surrounding materials of the magnetic nanoparticles. In the second experiment, we investigated the influence of the target position on the three-dimensional imaging of the magnetic nanoparticles in a realistic measurement setup for breast cancer imaging. The results show that the magnetic nanoparticles can be detected successfully. However, the intensity of the particles in the image depends on its position due to the path-dependent attenuation, the inhomogeneous microwave illumination of the breast, and the inhomogeneity of the magnetic field. Regarding the last point, we present an approach to compensate for the inhomogeneity of the magnetic field by computing a position-dependent correction factor based on the measured magnetic field intensity and the magnetic susceptibility of the magnetic particles. Moreover, the results indicate an influence of the polarizing magnetic field on the measured ultra-wideband signals even without magnetic nanoparticles. Such a disturbing influence of the polarizing magnetic field on the measurements should be reduced for a robust magnetic nanoparticles detection. Therefore, we analyzed the two-state (ON/OFF) and the sinusoidal modulation of the external magnetic field concerning the detectability of the magnetic nanoparticles with respect to these spurious effects, as well as their practical application.https://www.mdpi.com/1424-8220/21/19/6613ultra-widebandmagnetic nanoparticlesmicrowave imagingmedical imagingmagnetic modulationM-sequence radar technology |
| spellingShingle | Sebastian Ley Jürgen Sachs Bernd Faenger Ingrid Hilger Marko Helbig MNP-Enhanced Microwave Medical Imaging by Means of Pseudo-Noise Sensing Sensors ultra-wideband magnetic nanoparticles microwave imaging medical imaging magnetic modulation M-sequence radar technology |
| title | MNP-Enhanced Microwave Medical Imaging by Means of Pseudo-Noise Sensing |
| title_full | MNP-Enhanced Microwave Medical Imaging by Means of Pseudo-Noise Sensing |
| title_fullStr | MNP-Enhanced Microwave Medical Imaging by Means of Pseudo-Noise Sensing |
| title_full_unstemmed | MNP-Enhanced Microwave Medical Imaging by Means of Pseudo-Noise Sensing |
| title_short | MNP-Enhanced Microwave Medical Imaging by Means of Pseudo-Noise Sensing |
| title_sort | mnp enhanced microwave medical imaging by means of pseudo noise sensing |
| topic | ultra-wideband magnetic nanoparticles microwave imaging medical imaging magnetic modulation M-sequence radar technology |
| url | https://www.mdpi.com/1424-8220/21/19/6613 |
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