S. B. King, J. Bellec, V. Volotovskyy, H-Y. Lin, C. P. Bidinosti, K. Jasinski, M. J. Smith, and B. Tomanek Institute for Biodiagnostics, National Research Council of Canada, Winnipeg, Manitoba, Canada, Department of Physics, University of Winnipeg, Winnipeg, Manitoba, Canada, Department of Magnetic Resonance Imaging, Polish Academy of Sciences, H. Niewodniczanski Institute of Nuclear Physics, K...

One of the main topics to be investigated at the recently launched large (A(source) = 1.0 × 0.9 m(2)) ITER relevant RF driven negative ion test facility ELISE (Extraction from a Large Ion Source Experiment) is the connection between the homogeneity of the plasma parameters close to the extraction system and the homogeneity of the extracted negative hydrogen ion beam. While several diagnostics t...

PURPOSE The B0 and B1+ maps required for calculation of the radiofrequency (RF) pulse of parallel transmission (pTx) are obtained in calibration scans; however, they may be affected by respiratory motion. We aimed to compare the reproducibility of B0 and B1+ maps and gradient echo (GRE) images of the brain scanned with pTx at 7T between free-breathing (FB) and breath-holding (BH) conditions dur...

For heating and current drive the neutral beam injection system for ITER requires a 1 MeV deuterium beam for up to 1 h pulse length. In order to inject the required 17 MW the large area source (1.9m x 0.9m) has to deliver 40 A of negative ion current at the specified source pressure of 0.3 Pa. In 2007 the IPP RF driven negative hydrogen ion source was chosen as the new reference source for the ...

PURPOSE In oncology, texture features extracted from positron emission tomography with 18-fluorodeoxyglucose images (FDG-PET) are of increasing interest for predictive and prognostic studies, leading to several tens of features per tumor. To select the best features, the use of a random forest (RF) classifier was investigated. METHODS Sixty-five patients with an esophageal cancer treated with...

Conventional magnetic resonance spectroscopic imaging (MRSI), also known as phase-encoded (PE) chemical shift imaging (CSI), suffers from both low signal-to-noise ratio (SNR) of the brain metabolites, as well as inflexible tradeoffs between acquisition time and spatial resolution. In addition, although CSI at higher main field strengths, e.g. 7 Tesla (T), offers improved SNR over clinical 1.5T ...

1. Introduction The increasing interest in MRI at high magnetic field (i.e. 3T and above) has mainly been driven by neuro-imaging applications. More specifically, the higher sensitivity to detect activations in functional neuro-imaging studies was a main incentive. With the more widespread availability of high field systems many other applications benefit from the main advantage of higher magne...

INTRODUCTION – In clinical practice, imaging of the intracranial arteries, such as the Circle of Willis (CoW), is performed most frequently with 3D TOF angiography. This noninvasive technique uses a T1-weighted RF-spoiled gradient echo (SPGR) sequence, typically in conjuction with multiple overlapping slabs (MOTSA) and RF slab excitation pulses with ramped excitation profile (TONE) to reduce bl...

Introduction Ultra-high magnetic field strength, as widely utilised in small animal MRI systems, has advantages of being able to enhance signal-to-noise ratio (SNR) and gain high spectral resolution [1]. However, the homogeneity of B1 field worsens along with the move to higher RF-frequencies. Methods such as RF shimming and transmit SENSE, which require transceive volume-arrays had been propos...

Cardiac magnetic resonance imaging (MRI) at high field presents challenges because of the high specific absorption rate and significant transmit field (B1+ ) inhomogeneities. Parallel transmission MRI offers the ability to correct for both issues at the level of individual radiofrequency (RF) pulses, but must operate within strict hardware and safety constraints. The constraints are themselves ...