Florian Griese

University Medical Center Hamburg - Eppendorf · Bio medical Imaging

Advances in micromachinery and nanotechnology, such as magnetically actuated microrobots for navigating in viscous environments, are important driving forces in medicine. Recently, it has been shown that the spatial orientation of an ensemble of immobilized nanoparticles with parallel-aligned magnetic easy axes has an effect on the magnetization re...

Die Magnetpartikelbildgebung (MPI) ist eine junge tomographische Bildgebungstechnik, die magnetische Nanopartikel mit einer hohen räumlichen und zeitlichen Auflösung quantitativ abbildet. Eine gängige Methode zur Rekonstruktion von MPI-Daten ist die Systemmatrix (SM)-basierte Rekonstruktion. Die komplexwertige SM wird in einer zeitaufwändigen Kalib...

Magnetic particle imaging (MPI) data is commonly reconstructed using a system matrix acquired in a time-consuming calibration measurement. Compared to model-based reconstruction, the calibration approach has the important advantage that it takes into account both complex particle physics and system imperfections. However, this has the disadvantage...

Purpose Using 4D magnetic particle imaging (MPI), intravascular optical coherence tomography (IVOCT) catheters are tracked in real time in order to compensate for image artifacts related to relative motion. Our approach demonstrates the feasibility for bimodal IVOCT and MPI in-vitro experiments. Material and methods During IVOCT imaging of a steno...

Magnetic particle imaging is a tomographic imaging technique capable of measuring the local concentration of magnetic nanoparticles that can be used as tracers in biomedical applications. Since MPI is still at a very early stage of development, there are only a few MPI systems worldwide that are primarily operated by technical research groups that...

Purpose: Using 4D magnetic particle imaging (MPI), intravascular optical coherence tomography (IVOCT) catheters are tracked in real time in order to compensate for image artifacts related to relative motion. Our approach demonstrates the feasibility for bimodal IVOCT and MPI in-vitro experiments. Material and Methods: During IVOCT imaging of a sten...

Intravascular optical coherence tomography (IVOCT) is a catheter based image modality allowing for high resolution imaging of vessels. It is based on a fast sequential acquisition of A-scans with an axial spatial resolution in the range of 5 to 10 {\mu}m, i.e., one order of magnitude higher than in conventional methods like intravascular ultrasound...

Magnetic Particle Imaging (MPI) has been successfully used to visualize the distribution of superparamagnetic nanoparticles within 3D volumes with high sensitivity in real time. Since the magnetic field topology of MPI scanners is well suited for applying magnetic forces on particles and micron-sized ferromagnetic devices, MPI has been recently use...

Magnetic Particle Imaging (MPI) has been successfully used to visualize the distribution of superparamagnetic nanoparticles within 3D volumes with high sensitivity in real time. Since the magnetic field topology of MPI scanners is well suited for applying magnetic forces on particles and micron-sized ferromagnetic devices, MPI has been recently use...

Magnetic particle imaging (MPI) data is commonly reconstructed using a system matrix acquired in a time-consuming calibration measurement. The calibration approach has the important advantage over model-based reconstruction that it takes the complex particle physics as well as system imperfections into account. This benefit comes for the cost that...

Determining the brain perfusion is an important task for diagnosis of vascular diseases such as occlusions and intracerebral haemorrhage. Even after successful diagnosis, there is a high risk of restenosis or rebleeding such that patients need intense attention in the days after treatment. Within this work, we present a diagnostic tomographic image...

Purpose Intravascular optical coherence tomography (IVOCT) is a catheter‐based image modality allowing for high‐resolution imaging of vessels. It is based on a fast sequential acquisition of A‐scans with an axial spatial resolution in the range of 5–10 μm, that is, one order of magnitude higher than in conventional methods like intravascular ultras...

Magnetic Particle Imaging (MPI) is a highly sensitive imaging method that enables the visualization of magnetic tracer materials with a temporal resolution of more than 46 volumes per second. In MPI the size of the field of view scales with the strengths of the applied magnetic fields. In clinical applications those strengths are limited by periphe...

Determining the brain perfusion is an important task for the diagnosis and treatment of vascular diseases such as occlusions and intracerebral haemorrhage. Even after successful diagnosis and treatment, there is a high risk of restenosis or rebleeding such that patients need intense and frequent attention in the days after treatment. Within this wo...

Die Magnetpartikelbildgebung (engl. Magnetic-Particle-Imaging, MPI) ist eine Bildgebungsmodalität, die auf der Darstellung super-paramagnetischer Nanopartikeln unter Verwendung von statischen und dynamischen Magnetfeldern basiert [1]. Das Bildgebungsverfahren weist eine hohe zeitliche Auflӧsung von über 40 Volumen pro Sekunde auf und ist mit einer...

In Magnetic Particle Imaging the spatial distribution of superparamagnetic iron-oxide nanoparticles is determined using oscillating magnetic fields. The change of particle magnetization is recorded with receive coils. Spatial encoding is achieved with a superimposed gradient field featuring a field-free point. Particles not located in the vicinity...

Real-time target localization in ultrasound is useful in many clinical and scientific areas. For example in radiation therapy tumors can be localized in real-time and irradiated with a high accuracy. To measure the position of an ultrasound target in a global coordinate system or to extend the tracking volume by moving the ultrasound transducer an...