Pilot analysis of magnetic resonance imaging-based contributors to patient-centred optimization of mandibular advancement devices in obstructive sleep apnea.

Mandibular advancement devices are an effective treatment option for obstructive sleep apnea. While their efficacy depends on the degree of mandibular protrusion, other contributing factors influencing the optimal outcome are not fully understood. This magnetic resonance imaging-based pilot study aimed at investigating whether there are promising planimetric parameters that may be related to the optimal therapeutic position.

Bare-Metal Stent Tracking with Magnetic Particle Imaging.

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.

theranostic platform combining highly localized magnetic fluid hyperthermia, magnetic particle imaging, and thermometry in 3D.

Theranostic platforms, combining diagnostic and therapeutic approaches within one system, have garnered interest in augmenting invasive surgical, chemical, and ionizing interventions. Magnetic particle imaging (MPI) offers a quite recent alternative to established radiation-based diagnostic modalities with its versatile tracer material (superparamagnetic iron oxide nanoparticles, SPION). It also offers a bimodal theranostic framework that can combine tomographic imaging with therapeutic techniques using the very same SPION.

Heating of Large Endovascular Stents and Stent Grafts in Magnetic Particle Imaging-Influence of Measurement Parameters and Isocenter Distance.

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.

[Magnetic particle imaging : From research to the prospect of clinical use].

Background: Magnetic particle imaging offers far-reaching potential with a unique range of applications.

Objectives: Identification of application scenarios with added value for clinical use.

Methods: Overview of previous application scenarios in phantom and small animal models, evaluation of dual-use potential.

First Dedicated Balloon Catheter for Magnetic Particle Imaging.

Vascular interventions are a promising application of Magnetic Particle Imaging enabling a high spatial and temporal resolution without using ionizing radiation. The possibility to visualize the vessels as well as the devices, especially at the same time using multi-contrast approaches, enables a higher accuracy for diagnosis and treatment of vascular diseases. Different techniques to make devices MPI visible have been introduced so far, such as varnish markings or filling of balloons.

Bimodal Interventional Instrument Markers for Magnetic Particle Imaging and Magnetic Resonance Imaging-A Proof-of-Concept Study.

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.

Navigation of a magnetic micro-robot through a cerebral aneurysm phantom with magnetic particle imaging.

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.

Heating of an Aortic Stent for Coarctation Treatment During Magnetic Particle Imaging and Magnetic Resonance Imaging-A Comparative In Vitro Study.

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.

Magnetic Particle Imaging: In vitro Signal Analysis and Lumen Quantification of 21 Endovascular Stents.

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.

Efficient hybrid 3D system calibration for magnetic particle imaging systems using a dedicated device.

Image reconstruction in magnetic particle imaging is often performed using a system matrix based approach. The acquisition of a system matrix is a time-consuming calibration which may take several weeks and thus, is not feasible for a clinical device. Due to hardware characteristics of the receive chain, a system matrix may not even be used in similar devices but has to be acquired for each imager.

A New Phantom for Individual Verification of the Dose Distribution in Precision Radiotherapy for Head-and-Neck Cancer.

Background/aim: Many patients with head-and-neck cancers receive radiotherapy. Treatment planning can be very complex in case of dental fillings or implants that cause metal artefacts. Verification of dose distributions may be performed using specific phantoms.

Magnetic particle imaging in vascular medicine.

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.

Magnetic Particle Imaging: Artifact-Free Metallic Stent Lumen Imaging in a Phantom Study.

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.

Magnetic Particle Imaging meets Computed Tomography: first simultaneous imaging.

Magnetic Particle Imaging (MPI) is a promising new tomographic modality for fast as well as three-dimensional visualization of magnetic material. For anatomical or structural information an additional imaging modality such as computed tomography (CT) is required. In this paper, the first hybrid MPI-CT scanner for multimodal imaging providing simultaneous data acquisition is presented.

Tracking the Growth of Superparamagnetic Nanoparticles with an In-Situ Magnetic Particle Spectrometer (INSPECT).

Magnetic Particle Spectroscopy (MPS) is a measurement technique to determine the magnetic properties of superparamagnetic iron oxide nanoparticles (SPIONs) in an oscillating magnetic field as applied in Magnetic Particle Imaging (MPI). State of the art MPS devices are solely capable of measuring the magnetization response of the SPIONs to an oscillatory magnetic excitation retrospectively, i.e.

Moving table magnetic particle imaging: a stepwise approach preserving high spatio-temporal resolution.

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 (FoV) scales with the strengths of the applied magnetic fields. In clinical applications, those strengths are limited by peripheral nerve stimulation, specific absorption rates, and the requirement to acquire images of high spatial resolution.

Corrigendum to "Polychromatic Iterative Statistical Material Image Reconstruction for Photon-Counting Computed Tomography".

[This corrects the article DOI: 10.1155/2016/5871604.].

Take a Deep Breath - Monitoring of Inhaled Nanoparticles with Magnetic Particle Imaging.

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 and studies and the technique can now be considered as an established preclinical imaging modality with a promising perspective of clinical applications.

Improvement of dose calculation in radiation therapy due to metal artifact correction using the augmented likelihood image reconstruction.

Background: Metal artifacts caused by high-density implants lead to incorrectly reconstructed Hounsfield units in computed tomography images. This can result in a loss of accuracy in dose calculation in radiation therapy. This study investigates the potential of the metal artifact reduction algorithms, Augmented Likelihood Image Reconstruction and linear interpolation, in improving dose calculation in the presence of metal artifacts.

Towards Picogram Detection of Superparamagnetic Iron-Oxide Particles Using a Gradiometric Receive Coil.

Superparamagnetic iron-oxide nanoparticles can be used in medical applications like vascular or targeted imaging. Magnetic particle imaging (MPI) is a promising tomographic imaging technique that allows visualizing the 3D nanoparticle distribution concentration in a non-invasive manner. The two main strengths of MPI are high temporal resolution and high sensitivity.