Design, construction and validation of a magnetic particle imaging (MPI) system for human brain imaging.

Magnetic Particle Imaging (MPI) was introduced in 2005 as a promising, tracer-based medical imaging modality with the potential for high sensitivity and spatial resolution. Since then, numerous preclinical devices have been built but only a few human-scale devices, none of which targeted functional neuroimaging. In this work, we probe the challenges of scaling the technology to meet the needs of human functional neuroimaging with sufficient sensitivity for detecting the hemodynamic changes following brain activation with a spatio-temporal resolution comparable to current functional Magnetic Resonance Imaging (fMRI) approaches.

Open-source device for high sensitivity magnetic particle spectroscopy, relaxometry, and hysteresis loop tracing.

Magnetic nanoparticles (MNPs) are used extensively across numerous disciples, with applications including Magnetic Particle Imaging (MPI), targeted hyperthermia, deep brain stimulation, immunoassays, and thermometry. The assessment of MNPs, especially those being designed for MPI, is performed with magnetic particle spectrometers, relaxometers, loop tracers, or similar devices. Despite the many applications and the need for particle assessment, there are few consolidated resources for designing or building such a MNP assessment system.

Towards measuring the effect of flow in blood T assessed in a flow phantom and in vivo.

Measurement of the blood T time using conventional myocardial T mapping methods has gained clinical significance in the context of extracellular volume (ECV) mapping and synthetic hematocrit (Hct). However, its accuracy is potentially compromised by in-flow of non-inverted/non-saturated spins and in-flow of spins which are not partially saturated from previous imaging pulses. Bloch simulations were used to analyze various flow effects separately.

Magnetic resonance fingerprinting for simultaneous renal T and mapping in a single breath-hold.

Purpose: To evaluate the use of magnetic resonance fingerprinting (MRF) for simultaneous quantification of and in a single breath-hold in the kidneys.

Methods: The proposed kidney MRF sequence was based on MRF echo-planar imaging. Thirty-five measurements per slice and overall 4 slices were measured in 15.

Dissolved hyperpolarized xenon-129 MRI in human kidneys.

Purpose: To assess the feasibility of using dissolved hyperpolarized xenon-129 ( Xe) MRI to study renal physiology in humans at 3 T.

Methods: Using a flexible transceiver RF coil, dynamic and spatially resolved Xe spectroscopy was performed in the abdomen after inhalation of hyperpolarized Xe gas with 3 healthy male volunteers. A transmit-only receive-only RF coil array was purpose-built to focus RF excitation and enhance sensitivity for dynamic imaging of Xe uptake in the kidneys using spoiled gradient echo and balanced steady-state sequences.