Deep brain stimulation (DBS) is used increasingly in the field of movement disorders. The implanted electrodes create not only a prior risk to patient safety during MRI, but also a unique opportunity in the collection of functional MRI data conditioned by direct neural stimulation. We evaluated MRI-related heating for bilateral neurostimulation systems used for DBS with an emphasis on assessing...

In vivo detection of transplanted stem cells is requisite for improving stem cell-based treatments by developing a thorough understanding of their therapeutic mechanisms. MRI tracking of magnetically labeled cells is non-invasive and is suitable for longitudinal studies. Molday ION Rhodamine-B™ (MIRB) is a new superparamagnetic iron oxide (SPIO) contrast agent specifically formulated for cell l...

Three weeks after severe traumatic brain injury (pedestrian hit by a car) and correction of initial intracranial hypertension, a brain MRI is performed in a 22-yearold woman, who remains in a comatose state (Glasgow Coma Scale at 4, with withdrawal to painful stimuli; abolition of photomotor reflex; persistence of corneal and cough reflexes). Fluid-attenuated inversion recovery and T2*-weighted...

Principles and concepts of gradient echo (GRE) imaging are the basis of many applications on modern MR-systems. The most obvious difference between Spin Echo and GRE imaging is related to the pulse sequence elements that are used to generate an MR signal (see figure 1). While two rf-pulses (90 and 180) are used for spin refocusing and spin echo generation, GRE imaging is based on only a single ...

PURPOSE To develop a purpose-built quiet echo planar imaging capability for fetal functional and diffusion scans, for which acoustic considerations often compromise efficiency and resolution as well as angular/temporal coverage. METHODS The gradient waveforms in multiband-accelerated single-shot echo planar imaging sequences have been redesigned to minimize spectral content. This includes a s...

  Background :Inversion recovery (IR) pulse sequences can generate T1-weighted images with a different range of inversion time (TI) to suppress or null the signal intensity (SI) for a specified tissue. In this study, we aimed to investigate the effect of TI values on the concentration of the contrast agent, which leads to a minimum signal intensity, using an inversion recovery T1-weighted 3-dim...

The use of magnetic resonance (MR) imaging is growing exponentially, in part because of the excellent anatomic and pathologic detail provided by the modality and because of recent technologic advances that have led to faster acquisition times. Radiology residents now are introduced in their 1st year of training to the MR pulse sequences routinely used in clinical imaging, including various spin...