In the presence of alternating-sinusoidal or rotating magnetic fields, magnetic nanoparticles will act to realign their magnetic moment with the applied magnetic field. The realignment is characterized by the nanoparticle's time constant, τ. As the magnetic field frequency is increased, the nanoparticle's magnetic moment lags the applied magnetic field at a constant angle for a given frequency,...

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Juhani Dabek Name of the doctoral dissertation Method development for ultra-low-field magnetic resonance imaging and magnetoencephalography Publisher School of Science Unit Department of Biomedical Engineering and Computational Science Series Aalto University publication series DOCTORAL DISSERTATIONS 42/2014 Field of research ...

OBJECTIVE The objective was to evaluate magnetic resonance imaging (MRI) issues (magnetic field interactions, heating, artifacts and functional alterations) at 1.5 T and 3 T for the Argus II Retinal Prosthesis (Second Sight Medical Products, Sylmar, CA, USA). MATERIALS AND METHODS Standardized protocols were used to assess magnetic field interactions (translational attraction and torque; 3 T,...

Magnetic resonance imaging (MRI) is being rapidly integrated for cancer treatments-such systems are referred to as MRI-guided radiation therapy (MRIgRT). As the magnet of an MRI scanner is always on, the presence of a strong static magnetic field from the MRI scanner during radiotherapy delivery presents new challenges. One of the challenges is that a personal radiation dosimeter used to estima...

Magnetic source MRI (msMRI) has been developed recently for direct detections of neuronal magnetic fields to map brain activity. However, whether MRI can be used for direct detection of neuronal activity is a matter of debate. Controversial theoretical and experimental results have been reported. In this work, theoretical modeling and experimental validation have been presented to demonstrate t...

Gastric digestion is crucial for protein breakdown. Magnetic resonance techniques have a great deal of potential but remain underexplored with regard to their application in the study food via MRI-markers, such as transverse (R2) and longitudinal (R1) relaxation rates. R2 has been used monitor gastric whey gels, only static vitro model. It essential investigate whether rates can be valid measur...

PURPOSE In-vitro evaluation of the feasibility of 4D real time tracking of endovascular devices and stenosis treatment with a magnetic particle imaging (MPI) / magnetic resonance imaging (MRI) road map approach and an MPI-guided approach using a blood pool tracer. MATERIALS AND METHODS A guide wire and angioplasty-catheter were labeled with a thin layer of magnetic lacquer. For real time MPI ...

OBJECTIVES Limited data is available about incidence of acute transient symptoms associated with occupational exposure to static magnetic stray fields from MRI scanners. We aimed to assess the incidence of these symptoms among healthcare and research staff working with MRI scanners, and their association with static magnetic field exposure. METHODS We performed an observational study among 36...

magnetic nanoparticles attracted a great deal of attention in the medical applications due to their unique properties. the most exceptional property of magnetic particles is their response to a magnetic force, and this property has been utilized in applications such as drug targeting, bioseparation, contrast agents in magnetic resonance imaging (mri) and heating mediators for cancer therapy. in...