scholarly journals Experimental evaluation of different weighting schemes in magnetic particle imaging reconstruction

2015 ◽  
Vol 1 (1) ◽  
pp. 206-209 ◽  
Author(s):  
Patryk Szwargulski ◽  
Jürgen Rahmer ◽  
Mandy Ahlborg ◽  
Christian Kaethner ◽  
Thorsten M. Buzug
Keyword(s):  
Spatial Resolution ◽  
Magnetic Particle ◽  
System Function ◽  
Magnetic Particle Imaging ◽  
Imaging Reconstruction ◽  
New Strategy ◽  
Magnetic Tracer ◽  
Frequency Components ◽  
Particle Imaging ◽  
Weighting Methods

AbstractMagnetic Particle Imaging (MPI) is a new imaging technique with an outstanding sensitivity, a high temporal and spatial resolution. MPI is based on the excitation and detection of magnetic tracer material by using magnetic fields. The spatial resolution strongly depends on the reconstruction parameters and on the selection and weighting of the system function frequency components. Currently, no fundamental strategy to weight the system function for the reconstruction is given. In this contribution, the influence on the spatial resolution of different selection and weighting methods is analyzed. Thereby, a new strategy is proposed to select and weight the components with respect to their mixing order. As a result, it is confirmed that a weighted system function provides better results of image reconstruction than a non-weighted one. In addition to this, it is shown that the usage of the mixing order in combination with established weightings improves the resolution.

Increasing the sensitivity for stem cell monitoring in system-function based magnetic particle imaging

2016 ◽  
Vol 61 (9) ◽  
pp. 3279-3290 ◽  
Author(s):  
Kolja Them ◽  
J Salamon ◽  
P Szwargulski ◽  
S Sequeira ◽  
M G Kaul ◽  
...  
Keyword(s):  
Stem Cell ◽  
Magnetic Particle ◽  
System Function ◽  
Magnetic Particle Imaging ◽  
Cell Monitoring ◽  
Particle Imaging

Engineering of magnetic nanoparticles as magnetic particle imaging tracers

2021 ◽  
Author(s):  
Chang Lu ◽  
Linbo Han ◽  
Joanna Wang ◽  
Jiacheng Wan ◽  
Guosheng Song ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Spatial Resolution ◽  
Magnetic Particle ◽  
Imaging Technique ◽  
Non Invasive ◽  
Magnetic Particle Imaging ◽  
Particle Imaging

Magnetic particle imaging (MPI) has recently emerged as a promising non-invasive imaging technique. Engineering of magnetic nanoparticles (MNPs) is effective ways to enhance MPI sensitivity and spatial resolution.

scholarly journals Signal encoding in magnetic particle imaging: properties of the system function

2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Jürgen Rahmer ◽  
Jürgen Weizenecker ◽  
Bernhard Gleich ◽  
Jörn Borgert
Keyword(s):  
Magnetic Particle ◽  
System Function ◽  
Magnetic Particle Imaging ◽  
Signal Encoding ◽  
Particle Imaging ◽  
Imaging Properties

scholarly journals Artifacts in field free line magnetic particle imaging in the presence of inhomogeneous and nonlinear magnetic fields

2015 ◽  
Vol 1 (1) ◽  
pp. 245-248
Author(s):  
Hanne Medimagh ◽  
Patrick Weissert ◽  
Gael Bringout ◽  
Klaas Bente ◽  
Matthias Weber ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Image Reconstruction ◽  
Magnetic Fields ◽  
Magnetic Particle ◽  
Imaging Modality ◽  
System Function ◽  
Magnetic Particle Imaging ◽  
Gradient Fields ◽  
Particle Imaging ◽  
The Magnetic Field

AbstractIntroduction: Magnetic Particle Imaging (MPI) is an emerging medical imaging modality that detects super-paramagnetic particles exploiting their nonlinear magnetization response. Spatial encoding can be realized using a Field Free Line (FFL), which is generated, rotated and translated through the Field of View (FOV) using a combination of magnetic gradient fields and homogeneous excitation fields. When scaling up systems and/or enlarging the FOV in comparison to the scanner bore, ensuring homogeneity and linearity of the magnetic fields becomes challenging. The present contribution describes the first comprehensive, systematic study on the influence of magnetic field imperfections in FFL MPI. Methods: In a simulation study, 14 different FFL scanner setups have been examined. Starting from an ideal scanner using perfect magnetic fields, defined imperfections have been introduced in a range of configurations (nonlinear gradient fields, inhomogeneous excitation fields, or inhomogeneous receive fields, or a combination thereof). In the first part of the study, the voltage induced in the receive channels parallel and perpendicular to the FFL translation have been studied for discrete FFL angles. In the second part, an imaging process has been simulated comparing different image reconstruction approaches. Results: The induced voltage signals demonstrate illustratively the effect of the magnetic field imperfections. In images reconstructed using a Radon-based approach, the magnetic field imperfections lead to pronounced artifacts, especially if a deconvolution using the point spread function is performed. In images reconstructed using a system function based approach, variations in local image quality become visible. Conclusion: For Radon-based image reconstruction in FFL MPI in the presence of inhomogeneous and nonlinear magnetic fields, artifact correction methods will have to be developed. In this regard, a first approach has recently been presented by another group. Further research is required to elucidate the influence of magnetic field imperfections in MPI using a system function based approach.

Analysis of a 3-D System Function Measured for Magnetic Particle Imaging

2012 ◽  
Vol 31 (6) ◽  
pp. 1289-1299 ◽  
Author(s):  
J. Rahmer ◽  
J. Weizenecker ◽  
B. Gleich ◽  
J. Borgert
Keyword(s):  
Magnetic Particle ◽  
System Function ◽  
Magnetic Particle Imaging ◽  
Particle Imaging
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