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1. Functional magnetic resonance imaging (fMRI) at 1.5 T was used to investigate the lateralization of prefrontal cortex activity during internal mental calculation in 16 human volunteers (8 right-handed and 8 left-handed). Subjects were asked to perform two different tasks: 1) a serial subtraction of prime numbers and 2) a control task in which they(More)
RATIONALE AND OBJECTIVES The authors detect activation in the auditory cortex during cochlear electrical stimulation in deaf patients using functional magnetic resonance (MR) imaging. METHODS Stimulating electrode was inserted gently under local anesthesia close to the round window membrane of the cochlea in seven cochlear implant candidates. These(More)
Magnetic Resonance Images (MRI) of the temporomandibular joint (TMJ) are usually performed to study the opening/closing movements of the mandible and have up to now been pseudodynamic step-by-step images simulating condylar motion by post-processing reconstruction. The aim of this study was: 1. to optimize a TMJ cine-imaging method to give a better clinical(More)
Activations in the temporal lobes previously observed using positron emission tomography and auditory stimuli were partially reproduced with functional MRI and echo-planar imaging at 1.5 T in six volunteers performing tone and phoneme monitoring tasks. Verbal processing compared to a tone recognition task significantly activated a cortical area located in(More)
Magnetisation transfer ratio (MTR) is increasingly used to evaluate neurological disorders, especially those involving demyelination. It shows promise as a surrogate marker of disease progression in treatment trials in multiple sclerosis (MS) but the value measured is highly dependent on pulse sequence parameters, making it hard to include the technique in(More)
To improve 3D-time of flight (3D-TOF) magnetic resonance angiography, we used magnetisation transfer (MT) to increase the contrast between flowing blood and stationary tissues. With a 1.5 KHz off-resonance radio-frequency MT applied for 16 ms at a maximum power within specific absorption rate (SAR) limits, a 37% decrease in the signal of white matter was(More)
Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by a progressive degeneration of the striatonigral, olivo-ponto-cerebellar, and autonomic systems. Glial cytoplasmic inclusions (GCIs) containing alpha-synuclein represent the hallmark of MSA and are recapitulated in mice expressing alpha-synuclein in oligodendrocytes. To assess if(More)
Although conventional spin echo and gradient echo sequences are still in general use, the need to improve the temporal resolution of MRI and to study organ function has prompted to develop fast imaging techniques. These techniques are based on different approaches, but present common underlying principles which allow optimize k space fitting. As a result,(More)
The aim of magnetization transfer is to saturate the protons of the macromolecule pool with a radiofrequency (RF) pulse leading to differences in free water pool signal. Magnetization transfer (MT) contrast is difficult to achieve with the echo planar imaging (EPI) technique, although its short acquisition time would be most beneficial. Indeed, the RF(More)
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