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Wegner F, Friedrich T, Wattenberg M, Ackers J, Sieren MM, Kloeckner R, Barkhausen J, Buzug TM, Graeser M, von Gladiss A. Bare-Metal Stent Tracking with Magnetic Particle Imaging. Int J Nanomedicine 2024; 19:2137-2148. [PMID: 38476277 PMCID: PMC10929257 DOI: 10.2147/ijn.s447823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/12/2024] [Indexed: 03/14/2024] Open
Abstract
Purpose Magnetic particle imaging (MPI) is an emerging medical imaging modality that is on the verge of clinical use. In recent years, cardiovascular applications have shown huge potential like, e.g., intraprocedural imaging guidance of stent placement through MPI. Due to the lack of signal generation, nano-modifications have been necessary to visualize commercial medical instruments until now. In this work, it is investigated if commercial interventional devices can be tracked with MPI without any nano-modification. Material and Methods Potential MPI signal generation of nine endovascular metal stents was tested in a commercial MPI scanner. Two of the stents revealed sufficient MPI signal. Because one of the two stents showed relevant heating, the imaging experiments were carried out with a single stent model (Boston Scientific/Wallstent-Uni Endoprothesis, diameter: 16 mm, length: 60 mm). The nitinol stent and its delivery system were investigated in seven different scenarios. Therefore, the samples were placed at 49 defined spatial positions by a robot in a meandering pattern during MPI scans. Image reconstruction was performed, and the mean absolute errors (MAE) between the signals' centers of mass (COM) and ground truth positions were calculated. The stent material was investigated by magnetic particle spectroscopy (MPS) and vibrating sample magnetometry (VSM). To detect metallic components within the delivery system, nondestructive testing via computed tomography was performed. Results The tracking of the stent and its delivery system was possible without any nano-modification. The MAE of the COM were 1.49 mm for the stent mounted on the delivery system, 3.70 mm for the expanded stent and 1.46 mm for the delivery system without the stent. The results of the MPS and VSM measurements indicate that besides material properties eddy currents seem to be responsible for signal generation. Conclusion It is possible to image medical instruments with dedicated designs without modifications by means of MPI. This enables a variety of applications without compromising the mechanical and biocompatible properties of the instruments.
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Affiliation(s)
- Franz Wegner
- Institute for Interventional Radiology, University of Luebeck, Luebeck, Germany
| | - Thomas Friedrich
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering IMTE, Luebeck, Germany
| | - Maximilian Wattenberg
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering IMTE, Luebeck, Germany
| | - Justin Ackers
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering IMTE, Luebeck, Germany
| | - Malte Maria Sieren
- Institute for Interventional Radiology, University of Luebeck, Luebeck, Germany
- Department of Radiology and Nuclear Medicine, University of Luebeck, Luebeck, Germany
| | - Roman Kloeckner
- Institute for Interventional Radiology, University of Luebeck, Luebeck, Germany
| | - Joerg Barkhausen
- Department of Radiology and Nuclear Medicine, University of Luebeck, Luebeck, Germany
| | - Thorsten M Buzug
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering IMTE, Luebeck, Germany
- Institute of Medical Engineering, University of Lubeck, Luebeck, Germany
| | - Matthias Graeser
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering IMTE, Luebeck, Germany
- Institute of Medical Engineering, University of Lubeck, Luebeck, Germany
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Vogel P, Rückert MA, Greiner C, Günther J, Reichl T, Kampf T, Bley TA, Behr VC, Herz S. iMPI: portable human-sized magnetic particle imaging scanner for real-time endovascular interventions. Sci Rep 2023; 13:10472. [PMID: 37380707 DOI: 10.1038/s41598-023-37351-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 06/20/2023] [Indexed: 06/30/2023] Open
Abstract
Minimally invasive endovascular interventions have become an important tool for the treatment of cardiovascular diseases such as ischemic heart disease, peripheral artery disease, and stroke. X-ray fluoroscopy and digital subtraction angiography are used to precisely guide these procedures, but they are associated with radiation exposure for patients and clinical staff. Magnetic Particle Imaging (MPI) is an emerging imaging technology using time-varying magnetic fields combined with magnetic nanoparticle tracers for fast and highly sensitive imaging. In recent years, basic experiments have shown that MPI has great potential for cardiovascular applications. However, commercially available MPI scanners were too large and expensive and had a small field of view (FOV) designed for rodents, which limited further translational research. The first human-sized MPI scanner designed specifically for brain imaging showed promising results but had limitations in gradient strength, acquisition time and portability. Here, we present a portable interventional MPI (iMPI) system dedicated for real-time endovascular interventions free of ionizing radiation. It uses a novel field generator approach with a very large FOV and an application-oriented open design enabling hybrid approaches with conventional X-ray-based angiography. The feasibility of a real-time iMPI-guided percutaneous transluminal angioplasty (PTA) is shown in a realistic dynamic human-sized leg model.
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Affiliation(s)
- P Vogel
- Department of Experimental Physics 5 (Biophysics), Julius-Maximilians-University Würzburg, Würzburg, Germany.
| | - M A Rückert
- Department of Experimental Physics 5 (Biophysics), Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - C Greiner
- Department of Experimental Physics 5 (Biophysics), Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - J Günther
- Department of Experimental Physics 5 (Biophysics), Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - T Reichl
- Department of Experimental Physics 5 (Biophysics), Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - T Kampf
- Department of Experimental Physics 5 (Biophysics), Julius-Maximilians-University Würzburg, Würzburg, Germany
- Department of Diagnostic and Interventional Neuroradiology, University Hospital Würzburg, Würzburg, Germany
| | - T A Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany
| | - V C Behr
- Department of Experimental Physics 5 (Biophysics), Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - S Herz
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany
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Heating of Large Endovascular Stents and Stent Grafts in Magnetic Particle Imaging-Influence of Measurement Parameters and Isocenter Distance. Cardiovasc Intervent Radiol 2023; 46:392-399. [PMID: 36513764 PMCID: PMC10014652 DOI: 10.1007/s00270-022-03324-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/17/2022] [Indexed: 12/15/2022]
Abstract
PURPOSE Magnetic particle imaging (MPI) is a tomographic imaging modality with the potential for cardiovascular applications. In this context, the extent to which stents are heated should be estimated from safety perspective. Furthermore, the influence of the measurement parameters and stent distance to the isocenter of the MPI scanner on stent heating were evaluated. MATERIALS AND METHODS Nine different endovascular stents and stent grafts were tested in polyvinyl-chloride tubes. The stents had diameters from 10 to 31 mm, lengths between 25 and 100 mm and were made from stainless steel, nitinol or cobalt-chromium. The temperature differences were recorded with fiber-optic thermometers. All measurements were performed in a preclinical commercial MPI scanner. The measurement parameters were varied (drive field strengths: 3, 6, 9, 12 mT and selection field gradients: 0, 1.25 and 2.5 T/m). Furthermore, measurements with different distances to the scanner's isocenter were performed (100 to 0 mm). RESULTS All stents showed heating (maximum 53.1 K, minimum 4.6 K). The stent diameter directly correlated with the temperature increase. The drive field strength influenced the heating of the stents, whereas the selection field gradient had no detectable impact. The heating of the stents decreased with increasing distance from the scanner's isocenter and thus correlated with the loss of the scanner's magnetic field. CONCLUSION Stents can cause potentially harmful heating in MPI. In addition to the stent diameter and design, the drive field strength and the distance to the MPI scanner's isocenter must be kept in mind as influencing parameters.
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Wegner F, Lüdtke-Buzug K, Cremers S, Friedrich T, Sieren MM, Haegele J, Koch MA, Saritas EU, Borm P, Buzug TM, Barkhausen J, Ahlborg M. Bimodal Interventional Instrument Markers for Magnetic Particle Imaging and Magnetic Resonance Imaging—A Proof-of-Concept Study. NANOMATERIALS 2022; 12:nano12101758. [PMID: 35630979 PMCID: PMC9148153 DOI: 10.3390/nano12101758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/19/2022] [Accepted: 05/19/2022] [Indexed: 02/01/2023]
Abstract
The purpose of this work was to develop instrument markers that are visible in both magnetic particle imaging (MPI) and magnetic resonance imaging (MRI). The instrument markers were based on two different magnetic nanoparticle types (synthesized in-house KLB and commercial Bayoxide E8706). Coatings containing one of both particle types were fabricated and measured with a magnetic particle spectrometer (MPS) to estimate their MPI performance. Coatings based on both particle types were then applied on a segment of a nonmetallic guidewire. Imaging experiments were conducted using a commercial, preclinical MPI scanner and a preclinical 1 tesla MRI system. MPI image reconstruction was performed based on system matrices measured with dried KLB and Bayoxide E8706 coatings. The bimodal markers were clearly visible in both methods. They caused circular signal voids in MRI and areas of high signal intensity in MPI. Both the signal voids as well as the areas of high signal intensity were larger than the real marker size. Images that were reconstructed with a Bayoxide E8706 system matrix did not show sufficient MPI signal. Instrument markers with bimodal visibility are essential for the perspective of monitoring cardiovascular interventions with MPI/MRI hybrid systems.
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Affiliation(s)
- Franz Wegner
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, 23562 Luebeck, Germany; (M.M.S.); (J.B.)
- Correspondence: ; Tel.: +49-451-500-17001
| | - Kerstin Lüdtke-Buzug
- Institute of Medical Engineering, University of Luebeck, 23538 Luebeck, Germany; (K.L.-B.); (T.F.); (M.A.K.); (T.M.B.); (M.A.)
| | - Sjef Cremers
- Nano4Imaging, 40225 Duesseldorf, Germany; (S.C.); (P.B.)
| | - Thomas Friedrich
- Institute of Medical Engineering, University of Luebeck, 23538 Luebeck, Germany; (K.L.-B.); (T.F.); (M.A.K.); (T.M.B.); (M.A.)
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering IMTE, 23562 Luebeck, Germany
| | - Malte M. Sieren
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, 23562 Luebeck, Germany; (M.M.S.); (J.B.)
| | - Julian Haegele
- Zentrum für Radiologie und Nuklearmedizin, 04103 Dormagen, Germany;
| | - Martin A. Koch
- Institute of Medical Engineering, University of Luebeck, 23538 Luebeck, Germany; (K.L.-B.); (T.F.); (M.A.K.); (T.M.B.); (M.A.)
| | - Emine U. Saritas
- Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara, Turkey;
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, 06800 Ankara, Turkey
| | - Paul Borm
- Nano4Imaging, 40225 Duesseldorf, Germany; (S.C.); (P.B.)
| | - Thorsten M. Buzug
- Institute of Medical Engineering, University of Luebeck, 23538 Luebeck, Germany; (K.L.-B.); (T.F.); (M.A.K.); (T.M.B.); (M.A.)
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering IMTE, 23562 Luebeck, Germany
| | - Joerg Barkhausen
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, 23562 Luebeck, Germany; (M.M.S.); (J.B.)
| | - Mandy Ahlborg
- Institute of Medical Engineering, University of Luebeck, 23538 Luebeck, Germany; (K.L.-B.); (T.F.); (M.A.K.); (T.M.B.); (M.A.)
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering IMTE, 23562 Luebeck, Germany
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Navigation of a magnetic micro-robot through a cerebral aneurysm phantom with magnetic particle imaging. Sci Rep 2021; 11:14082. [PMID: 34234207 PMCID: PMC8263782 DOI: 10.1038/s41598-021-93323-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 06/11/2021] [Indexed: 12/02/2022] Open
Abstract
Cerebral aneurysms are potentially life threatening and nowadays treated by a catheter-guided coiling or by a neurosurgical clipping intervention. Here, we propose a helically shaped magnetic micro-robot, which can be steered by magnetic fields in an untethered manner and could be applied for a novel coiling procedure. This is shown by navigating the micro-robot through an additively manufactured phantom of a human cerebral aneurysm. The magnetic fields are applied with a magnetic particle imaging (MPI) scanner, which allows for the navigation and tomographic visualization by the same machine. With MPI the actuation process can be visualized with a localization accuracy of 0.68 mm and an angiogram can be acquired both without any radiation exposure. First in-vitro phantom experiments are presented, showing an idea of a robot conducted treatment of cerebral aneurysms.
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Magnetic particle imaging for artifact-free imaging of intracranial flow diverter stents: A phantom study. Phys Med 2021; 88:65-70. [PMID: 34192659 DOI: 10.1016/j.ejmp.2021.06.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 05/10/2021] [Accepted: 06/21/2021] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Magnetic Particle Imaging (MPI) is a new, background- and radiation-free tomographic imaging method that enables near real-time imaging of superparamagnetic iron-oxide nanoparticles (SPIONs) with high temporal and spatial resolution. This phantom study aims to investigate the potential of MPI for visualization of the stent lumen in intracranial flow diverters (FD). METHODS Nitinol FD of different dimensions (outer diameter: 3.5 mm, 4.0 mm, 5.5 mm; total length: 22-40 mm) were scanned in vascular phantoms in a custom-built MPI scanner (in-plane resolution: ~ 2 mm, field of view: 65 mm length, 29 mm diameter). Phantoms were filled with diluted (1:50) SPION tracer agent Ferucarbotran (10 µmol (Fe)/ml; NaCL). Each phantom was measured in 32 different projections (overall acquisition time per image: 3200 ms, 5averages). After image reconstruction from raw data, two radiologists assessed image quality using a 5-point Likert scale. The signal intensity profile was measured using a semi-automatic evaluation tool. RESULTS MPI visualized the lumen of all FD without relevant differences between the stented vessel phantom and the reference phantom. At 3.5 mm image quality was slightly inferior to the larger diameters. The FD themselves neither generated an MPI signal nor did they lead to relevant imaging artifacts. Ratings of both radiologists showed no significant difference, interrater reliability was good (ICC 0.84). A quantitative evaluation of the signal intensity profile did not reveal any significant differences (p > 0.05) either. CONCLUSION MPI visualizes the lumen of nitinol FD stents in vessel phantoms without relevant stent-induced artifacts.
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Grzyska U, Friedrich T, Sieren MM, Stahlberg E, Oechtering TH, Ahlborg M, Buzug TM, Frydrychowicz A, Barkhausen J, Haegele J, Wegner F. Heating of an Aortic Stent for Coarctation Treatment During Magnetic Particle Imaging and Magnetic Resonance Imaging-A Comparative In Vitro Study. Cardiovasc Intervent Radiol 2021; 44:1109-1115. [PMID: 33723668 PMCID: PMC8189960 DOI: 10.1007/s00270-021-02795-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 02/02/2021] [Indexed: 11/13/2022]
Abstract
PURPOSE To evaluate heating of a redilatable stent for the treatment of aortic coarctation in neonates and small children in the new imaging modality magnetic particle imaging and established magnetic resonance imaging. MATERIALS AND METHODS The cobalt-chromium stent (BabyStent, OSYPKA AG, Rheinfelden, Germany) has a stent design which allows for redilatation and adjustment of the diameter from 6 to 16 mm for a use in aortic coarctation. The stent loses its radial integrity while opening at predetermined breaking points at a diameter of 14 mm or 16 mm, respectively. We measured the temperature increase in the stent at different diameters during 7-min magnetic particle imaging and magnetic resonance imaging scans with fiber optic thermometers under static conditions surrounded by air. In magnetic particle imaging, stents with diameters from 6 to 16 mm were tested while in magnetic resonance imaging only stents with diameters of 6 mm and 14 mm were investigated exemplarily. RESULT In magnetic particle imaging, the measured temperature differences increased up to 4.7 K with growing diameters, whereas the opened stents with discontinuous struts at 14 and 16 mm showed only minimal heating of max. 0.5 K. In contrast to magnetic particle imaging, our measurements showed no heating of the stents during magnetic resonance imaging under identical conditions. CONCLUSION The BabyStent did show only slight heating in magnetic particle imaging and no detectable temperature increase in magnetic resonance imaging.
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Affiliation(s)
- Ulrike Grzyska
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany.
| | - Thomas Friedrich
- Institute of Medical Engineering, University of Lübeck, Lübeck, Germany
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering, Lübeck, Germany
| | - Malte M Sieren
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany
| | - Erik Stahlberg
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany
| | - Thekla H Oechtering
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany
| | - Mandy Ahlborg
- Institute of Medical Engineering, University of Lübeck, Lübeck, Germany
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering, Lübeck, Germany
| | - Thorsten M Buzug
- Institute of Medical Engineering, University of Lübeck, Lübeck, Germany
- Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering, Lübeck, Germany
| | - Alex Frydrychowicz
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany
| | - Joerg Barkhausen
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany
| | - Julian Haegele
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany
- Zentrum für Radiologie und Nuklearmedizin Rheinland, Dormagen, Germany
| | - Franz Wegner
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany
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Wegner F, von Gladiss A, Haegele J, Grzyska U, Sieren MM, Stahlberg E, Oechtering TH, Lüdtke-Buzug K, Barkhausen J, Buzug TM, Friedrich T. Magnetic Particle Imaging: In vitro Signal Analysis and Lumen Quantification of 21 Endovascular Stents. Int J Nanomedicine 2021; 16:213-221. [PMID: 33469281 PMCID: PMC7810673 DOI: 10.2147/ijn.s284694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/11/2020] [Indexed: 11/23/2022] Open
Abstract
Purpose Endovascular stents are medical devices, which are implanted in stenosed blood vessels to ensure sufficient blood flow. Due to a high rate of in-stent re-stenoses, there is the need of a noninvasive imaging method for the early detection of stent occlusion. The evaluation of the stent lumen with computed tomography (CT) and magnetic resonance imaging (MRI) is limited by material-induced artifacts. The purpose of this work is to investigate the potential of the tracer-based modality magnetic particle imaging (MPI) for stent lumen visualization and quantification. Methods In this in vitro study, 21 endovascular stents were investigated in a preclinical MPI scanner. Therefore, the stents were implanted in vessel phantoms. For the signal analysis, the phantoms were scanned without tracer material, and the signal-to-noise-ratio was analyzed. For the evaluation of potential artifacts and the lumen quantification, the phantoms were filled with diluted tracer agent. To calculate the stent lumen diameter a calibrated threshold value was applied. Results We can show that it is possible to visualize the lumen of a variety of endovascular stents without material induced artifacts, as the stents do not generate sufficient signals in MPI. The stent lumen quantification showed a direct correlation between the calculated and nominal diameter (r = 0.98). Conclusion In contrast to MRI and CT, MPI is able to visualize and quantify stent lumina very accurately.
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Affiliation(s)
- Franz Wegner
- Department of Radiology and Nuclear Medicine, University of Lübeck, Lübeck, Germany
| | | | - Julian Haegele
- Department of Radiology and Nuclear Medicine, University of Lübeck, Lübeck, Germany.,Zentrum für Radiologie und Nuklearmedizin Rheinland, Dormagen, Germany
| | - Ulrike Grzyska
- Department of Radiology and Nuclear Medicine, University of Lübeck, Lübeck, Germany
| | - Malte Maria Sieren
- Department of Radiology and Nuclear Medicine, University of Lübeck, Lübeck, Germany
| | - Erik Stahlberg
- Department of Radiology and Nuclear Medicine, University of Lübeck, Lübeck, Germany
| | | | | | - Joerg Barkhausen
- Department of Radiology and Nuclear Medicine, University of Lübeck, Lübeck, Germany
| | - Thorsten M Buzug
- Institute of Medical Engineering, University of Lübeck, Lübeck, Germany.,Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering, Lübeck, Germany
| | - Thomas Friedrich
- Institute of Medical Engineering, University of Lübeck, Lübeck, Germany.,Fraunhofer Research Institution for Individualized and Cell-Based Medical Engineering, Lübeck, Germany
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Etemadi H, Plieger PG. Magnetic Fluid Hyperthermia Based on Magnetic Nanoparticles: Physical Characteristics, Historical Perspective, Clinical Trials, Technological Challenges, and Recent Advances. ADVANCED THERAPEUTICS 2020. [DOI: 10.1002/adtp.202000061] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Hossein Etemadi
- School of Fundamental Sciences Massey University Palmerston North 4474 New Zealand
| | - Paul G. Plieger
- School of Fundamental Sciences Massey University Palmerston North 4474 New Zealand
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10
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Salamon J, Dieckhoff J, Kaul MG, Jung C, Adam G, Möddel M, Knopp T, Draack S, Ludwig F, Ittrich H. Visualization of spatial and temporal temperature distributions with magnetic particle imaging for liver tumor ablation therapy. Sci Rep 2020; 10:7480. [PMID: 32366912 PMCID: PMC7198551 DOI: 10.1038/s41598-020-64280-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 04/09/2020] [Indexed: 11/09/2022] Open
Abstract
Temperature-resolved magnetic particle imaging (MPI) represents a promising tool for medical imaging applications. In this study an approach based on a single calibration measurement was applied for highlighting the potential of MPI for monitoring of temperatures during thermal ablation of liver tumors. For this purpose, liver tissue and liver tumor phantoms embedding different superparamagnetic iron oxide nanoparticles (SPION) were prepared, locally heated up to 70 °C and recorded with MPI. Optimal temperature MPI SPIONs and a corresponding linear model for temperature calculation were determined. The temporal and spatial temperature distributions were compared with infrared (IR) camera results yielding quantitative agreements with a mean absolute deviation of 1 °C despite mismatches in boundary areas.
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Affiliation(s)
- J Salamon
- Department for Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.
| | - J Dieckhoff
- Department for Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - M G Kaul
- Department for Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - C Jung
- Department for Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - G Adam
- Department for Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - M Möddel
- Section for Biomedical Imaging, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.,Institute for Biomedical Imaging, Hamburg University of Technology, 21073, Hamburg, Germany
| | - T Knopp
- Section for Biomedical Imaging, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.,Institute for Biomedical Imaging, Hamburg University of Technology, 21073, Hamburg, Germany
| | - S Draack
- Institute of Electrical Measurement Science and Fundamental Electrical Engineering, TU Braunschweig, 38106, Braunschweig, Germany
| | - F Ludwig
- Institute of Electrical Measurement Science and Fundamental Electrical Engineering, TU Braunschweig, 38106, Braunschweig, Germany
| | - H Ittrich
- Department for Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
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Magnetic Particle Imaging: Artifact-Free Metallic Stent Lumen Imaging in a Phantom Study. Cardiovasc Intervent Radiol 2019; 43:331-338. [PMID: 31578634 DOI: 10.1007/s00270-019-02347-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 09/24/2019] [Indexed: 12/30/2022]
Abstract
PURPOSE To illustrate the potential of magnetic particle imaging (MPI) for stent lumen imaging in comparison with clinical computed tomography (CT) and magnetic resonance imaging (MRI). MATERIALS AND METHODS Imaging of eight tracer-filled, stented vessel phantoms and a tracer-filled, non-stented reference phantom for each diameter was performed on a preclinical MPI scanner: eight commercially available coronary stents of different dimensions (diameter: 3-4 mm; length: 11-38 mm) and materials (stainless steel, platinum-chromium) were implanted into silicone vessel phantoms. For comparison, all vessel phantoms were also visualized by MRI and CT. Two radiologists assessed the images regarding stent-induced artifacts using a 5-point grading scale. RESULTS The visualization of all stented vessel phantoms was achieved without stent-induced artifacts with MPI. In contrast, MRI and CT images revealed multiform stent-induced artifacts. CONCLUSION Given its clinical introduction, MPI has the potential to overcome the disadvantages of MRI and CT concerning the visualization of the stent lumen.
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12
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Herz S, Vogel P, Kampf T, Dietrich P, Veldhoen S, Rückert MA, Kickuth R, Behr VC, Bley TA. Magnetic Particle Imaging-Guided Stenting. J Endovasc Ther 2019; 26:512-519. [PMID: 31131684 DOI: 10.1177/1526602819851202] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Purpose:To assess the feasibility of magnetic particle imaging (MPI) to guide stenting in a phantom model. Materials and Methods: MPI is a new tomographic imaging method based on the background-free magnetic field detection of a tracer agent composed of superparamagnetic iron oxide nanoparticles (SPIOs). All experiments were conducted on a custom-built MPI scanner (field of view: 29-mm diameter, 65-mm length; isotropic spatial resolution 1-1.5-mm). Stenosis phantoms (n=3) consisted of polyvinyl chloride (PVC) tubes (8-mm inner diameter) prepared with centrally aligned cable binders to form a ~50% stenosis. A dedicated image reconstruction algorithm allowed precise tracking of endovascular instruments at 8 frames/s with a latency time of ~115 ms. A custom-made MPI-visible lacquer was used to manually label conventional guidewires, balloon catheters, and stainless steel balloon-expandable stents. Vascular stenoses were visualized by injecting a diluted SPIO tracer (ferucarbotran, 10 mmol iron/L) into the vessel phantoms. Balloon angioplasty and stent placement were performed by inflating balloon catheters and stent delivery balloons with diluted ferucarbotran. Results: After deployment of the stent, the markers on its ends were clearly visible. The applied lacquer markers were thin enough to not relevantly alter gliding properties of the devices while withstanding friction during the experiments. Placing an optimized flexible lacquer formulation on the preexisting radiopaque stent markers provided enough stability to withstand stent expansion. Final MPA confirmed successful stenosis treatment, facilitated by the disappearance of the lacquer markers on the stent due to differences in SPIO concentration. Thus, the in-stent lumen could be visualized without interference by the signal from the markers. Conclusion: Near real-time visualization of MPI-guided stenting of stenoses in a phantom model is feasible. Optimized MPI-visible markers can withstand the expansion process of stents.
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Affiliation(s)
- Stefan Herz
- 1 Department of Diagnostic and Interventional Radiology, Würzburg, Germany.,2 Comprehensive Heart Failure Center, University Hospital Würzburg, Germany
| | - Patrick Vogel
- 1 Department of Diagnostic and Interventional Radiology, Würzburg, Germany.,3 Department of Experimental Physics 5 (Biophysics), University of Würzburg, Germany
| | - Thomas Kampf
- 3 Department of Experimental Physics 5 (Biophysics), University of Würzburg, Germany.,4 Department of Diagnostic and Interventional Neuroradiology, University Hospital Würzburg, Germany
| | - Philipp Dietrich
- 1 Department of Diagnostic and Interventional Radiology, Würzburg, Germany
| | - Simon Veldhoen
- 1 Department of Diagnostic and Interventional Radiology, Würzburg, Germany
| | - Martin A Rückert
- 3 Department of Experimental Physics 5 (Biophysics), University of Würzburg, Germany
| | - Ralph Kickuth
- 1 Department of Diagnostic and Interventional Radiology, Würzburg, Germany
| | - Volker C Behr
- 3 Department of Experimental Physics 5 (Biophysics), University of Würzburg, Germany
| | - Thorsten A Bley
- 1 Department of Diagnostic and Interventional Radiology, Würzburg, Germany
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13
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Bakenecker AC, Ahlborg M, Debbeler C, Kaethner C, Buzug TM, Lüdtke-Buzug K. Magnetic particle imaging in vascular medicine. Innov Surg Sci 2018; 3:179-192. [PMID: 31579782 PMCID: PMC6604583 DOI: 10.1515/iss-2018-2026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 09/14/2018] [Indexed: 01/31/2023] Open
Abstract
Magnetic particle imaging (MPI) is a new medical imaging technique that enables three-dimensional real-time imaging of a magnetic tracer material. Although it is not yet in clinical use, it is highly promising, especially for vascular and interventional imaging. The advantages of MPI are that no ionizing radiation is necessary, its high sensitivity enables the detection of very small amounts of the tracer material, and its high temporal resolution enables real-time imaging, which makes MPI suitable as an interventional imaging technique. As MPI is a tracer-based imaging technique, functional imaging is possible by attaching specific molecules to the tracer material. In the first part of this article, the basic principle of MPI will be explained and a short overview of the principles of the generation and spatial encoding of the tracer signal will be given. After this, the used tracer materials as well as their behavior in MPI will be introduced. A subsequent presentation of selected scanner topologies will show the current state of research and the limitations researchers are facing on the way from preclinical toward human-sized scanners. Furthermore, it will be briefly shown how to reconstruct an image from the tracer materials' signal. In the last part, a variety of possible future clinical applications will be presented with an emphasis on vascular imaging, such as the use of MPI during cardiovascular interventions by visualizing the instruments. Investigations will be discussed, which show the feasibility to quantify the degree of stenosis and diagnose strokes and traumatic brain injuries as well as cerebral or gastrointestinal bleeding with MPI. As MPI is not only suitable for vascular medicine but also offers a broad range of other possible applications, a selection of those will be briefly presented at the end of the article.
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Affiliation(s)
- Anna C. Bakenecker
- Institute of Medical Engineering, University of Luebeck, Luebeck, Germany
| | - Mandy Ahlborg
- Institute of Medical Engineering, University of Luebeck, Luebeck, Germany
| | - Christina Debbeler
- Institute of Medical Engineering, University of Luebeck, Luebeck, Germany
| | - Christian Kaethner
- Institute of Medical Engineering, University of Luebeck, Luebeck, Germany
| | - Thorsten M. Buzug
- Institute of Medical Engineering, University of Luebeck, Luebeck, Germany
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14
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Carvalho PM, Felício MR, Santos NC, Gonçalves S, Domingues MM. Application of Light Scattering Techniques to Nanoparticle Characterization and Development. Front Chem 2018; 6:237. [PMID: 29988578 PMCID: PMC6026678 DOI: 10.3389/fchem.2018.00237] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 06/04/2018] [Indexed: 01/07/2023] Open
Abstract
Over the years, the scientific importance of nanoparticles for biomedical applications has increased. The high stability and biocompatibility, together with the low toxicity of the nanoparticles developed lead to their use as targeted drug delivery systems, bioimaging systems, and biosensors. The wide range of nanoparticles size, from 10 nm to 1 μm, as well as their optical properties, allow them to be studied using microscopy and spectroscopy techniques. In order to be effectively used, the physicochemical properties of nanoparticle formulations need to be taken into account, namely, particle size, surface charge distribution, surface derivatization and/or loading capacity, and related interactions. These properties need to be optimized considering the final nanoparticle intended biodistribution and target. In this review, we cover light scattering based techniques, namely dynamic light scattering and zeta-potential, used for the physicochemical characterization of nanoparticles. Dynamic light scattering is used to measure nanoparticles size, but also to evaluate their stability over time in suspension, at different pH and temperature conditions. Zeta-potential is used to characterize nanoparticles surface charge, obtaining information about their stability and surface interaction with other molecules. In this review, we focus on nanoparticle characterization and application in infection, cancer and cardiovascular diseases.
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Affiliation(s)
- Patrícia M Carvalho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Mário R Felício
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Nuno C Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Sónia Gonçalves
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Marco M Domingues
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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15
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Wegner F, Buzug TM, Barkhausen J. Take a Deep Breath - Monitoring of Inhaled Nanoparticles with Magnetic Particle Imaging. Theranostics 2018; 8:3691-3692. [PMID: 30026876 PMCID: PMC6037023 DOI: 10.7150/thno.27454] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 05/26/2018] [Indexed: 11/13/2022] Open
Abstract
Magnetic Particle Imaging (MPI) is a new imaging modality based on the visualization of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) using magnetic fields. The potential of MPI was recently evaluated in numerous ex vivo and in vivo studies and the technique can now be considered as an established preclinical imaging modality with a promising perspective of clinical applications.
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Affiliation(s)
- Franz Wegner
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Thorsten M. Buzug
- Institute of Medical Engineering, University of Lübeck, Building 64, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Joerg Barkhausen
- Department of Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Ratzeburger Allee 160, 23562 Lübeck, Germany
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