Comparison of commercial iron oxide-based MRI contrast agents with synthesized high-performance MPI tracers.

Magnetic particle imaging (MPI) recently emerged as a new tomographic imaging method directly visualizing the amount and location of superparamagnetic iron oxide particles (SPIOs) with high spatial resolution. To fully exploit the imaging performance of MPI, specific requirements are demanded on the SPIOs. Most important, a sufficiently high number of detectable harmonics of the receive signal spectrum is required.

Toward cardiovascular interventions guided by magnetic particle imaging: first instrument characterization.

Magnetic particle imaging has emerged as a new technique for the visualization and quantification of superparamagnetic iron oxide nanoparticles. It seems to be a very promising application for cardiovascular interventional radiology. A prerequisite for interventions is the artifact-free visualization of the required instruments and implants.

A specific absorption rate prediction concept for parallel transmission MR.

The specific absorption rate (SAR) is a limiting factor in high-field MR. SAR estimation is typically performed by numerical simulations using generic human body models. However, SAR concepts for single-channel radiofrequency transmission cannot be directly applied to multichannel systems.

Experimental generation of an arbitrarily rotated field-free line for the use in magnetic particle imaging.

Purpose: The concept of a magnetic field-free line (FFL), with regard to the novel tomographic modality magnetic particle imaging (MPI), was recently introduced. Theoretical approaches predict the improvement of sensitivity of MPI by a factor of ten replacing the conventionally used field-free point (FFP) by a FFL. In this work, an experimental apparatus for generating an arbitrarily rotated and translated FFL field is described and tested.

Prediction of the spatial resolution of magnetic particle imaging using the modulation transfer function of the imaging process.

The magnetic particle imaging method allows for the quantitative determination of spatial distributions of superparamagnetic nanoparticles in vivo. Recently, it was shown that the 1-D magnetic particle imaging process can be formulated as a convolution. Analyzing the width of the convolution kernel allows for predicting the spatial resolution of the method.

Efficient generation of a magnetic field-free line.

Purpose: Signal encoding in magnetic particle imaging (MPI) is achieved by moving a field-free point (FFP) through the region of interest. One way to increase the sensitivity of the method is to scan the region of interest with a field-free line (FFL) instead of the FFP. Recently, the first feasible FFL coil setup was introduced.

2D model-based reconstruction for magnetic particle imaging.

Purpose: Magnetic particle imaging (MPI) is a new quantitative imaging technique capable of determining the spatial distribution of superparamagnetic nanoparticles at high temporal and spatial resolution. For reconstructing this spatial distribution, the particle dynamics and the scanner properties have to be known. To date, they are obtained in a tedious calibration procedure by measuring the magnetization response of a small delta sample shifted through the measuring field.

Model-based reconstruction for magnetic particle imaging.

Magnetic particle imaging (MPI) is a new imaging modality capable of imaging distributions of superparamagnetic nanoparticles with high sensitivity, high spatial resolution and, in particular, high imaging speed. The image reconstruction process requires a system function, describing the mapping between particle distribution and acquired signal. To date, the system function is acquired in a tedious calibration procedure by sequentially measuring the signal of a delta sample at the positions of a grid that covers the field of view.