[BibTex]

Note: article

Abstract: It has been shown that magnetic particle imaging ({MPI}), an imaging method suggested in 2005, is capable of measuring the spatial distribution of magnetic nanoparticles. Since the particles can be administered as biocompatible suspensions, this method promises to perform well as a tracer-based medical imaging technique. It is capable of generating real-time images, which will be useful in interventional procedures, without utilizing any harmful radiation. To obtain a signal from the administered superparamagnetic iron oxide ({SPIO}) particles, a sinusoidal changing external homogeneous magnetic field is applied. To achieve spatial encoding, a gradient field is superimposed. Conventional {MPI} works with a spatial encoding field that features a field free point ({FFP}). To increase sensitivity, an improved spatial encoding field, featuring a field free line ({FFL}) can be used. Previous {FFL} scanners, featuring a 1-D excitation, could demonstrate the feasibility of the {FFL}-based {MPI} imaging process. In this work, an {FFL}-based {MPI} scanner is presented that features a 2-D excitation field and, for the first time, an electronic rotation of the spatial encoding field. Furthermore, the role of relaxation effects in {MPI} is starting to move to the center of interest. Nevertheless, no reconstruction schemes presented thus far include a dynamical particle model for image reconstruction. A first application of a model that accounts for relaxation effects in the reconstruction of {MPI} images is presented here in the form of a simplified, but well performing strategy for signal deconvolution. The results demonstrate the high impact of relaxation deconvolution on the {MPI} imaging process.

[BibTex]

Note: article

Abstract: It has been shown that magnetic particle imaging ({MPI}), an imaging method suggested in 2005, is capable of measuring the spatial distribution of magnetic nanoparticles. Since the particles can be administered as biocompatible suspensions, this method promises to perform well as a tracer-based medical imaging technique. It is capable of generating real-time images, which will be useful in interventional procedures, without utilizing any harmful radiation. To obtain a signal from the administered superparamagnetic iron oxide ({SPIO}) particles, a sinusoidal changing external homogeneous magnetic field is applied. To achieve spatial encoding, a gradient field is superimposed. Conventional {MPI} works with a spatial encoding field that features a field free point ({FFP}). To increase sensitivity, an improved spatial encoding field, featuring a field free line ({FFL}) can be used. Previous {FFL} scanners, featuring a 1-D excitation, could demonstrate the feasibility of the {FFL}-based {MPI} imaging process. In this work, an {FFL}-based {MPI} scanner is presented that features a 2-D excitation field and, for the first time, an electronic rotation of the spatial encoding field. Furthermore, the role of relaxation effects in {MPI} is starting to move to the center of interest. Nevertheless, no reconstruction schemes presented thus far include a dynamical particle model for image reconstruction. A first application of a model that accounts for relaxation effects in the reconstruction of {MPI} images is presented here in the form of a simplified, but well performing strategy for signal deconvolution. The results demonstrate the high impact of relaxation deconvolution on the {MPI} imaging process.