Stephan Gruber

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Gamma aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the human brain. It plays a decisive role in a variety of nervous system disorders, such as anxiety disorders, epilepsy, schizophrenia, insomnia, and many others. The reproducibility of GABA quantification results obtained with a single-voxel spectroscopy J-difference editing(More)
PURPOSE To retrospectively correlate changes in fractional anisotropy (FA) and mean diffusivity in gliomas at diffusion-tensor magnetic resonance (MR) imaging with the degree of tumor cell infiltration determined histologically. MATERIALS AND METHODS The institutional review board required neither ethics committee approval nor patient informed consent for(More)
Neurologic disease in glutaryl-CoA dehydrogenase (GCDH) deficiency usually presents with acute encephalopathic crises before 2 years of age. The authors report two previously asymptomatic patients with macrocephaly presenting with progressive neurologic deterioration and a severe leukoencephalopathy during adolescence or adulthood.
Currently, there is a lack of stand-alone geo-monitoring systems for harsh environments that are easy to configure, deploy and manage, while at the same time adhering to science grade quality requirements. In a joint computer and geoscience project we have built and deployed a wireless sensor network for measuring permafrost related parameters. Using these(More)
PURPOSE To compare the diagnostic quality of diffusion-weighted (DW) imaging schemes with regard to apparent diffusion coefficient (ADC) accuracy, ADC precision, and DW imaging contrast-to-noise ratio (CNR) for different types of lesions and breast tissue. MATERIALS AND METHODS Institutional review board approval and written, informed consent were(More)
Longitudinal and transverse relaxation times were measured for proton MRS signals from human brain metabolites at 3 T using a short-echo STEAM protocol and a surface coil as a transmitter/receiver. Volumes of interest containing mostly grey or mostly white matter were selected in occipital lobes of healthy subjects and relaxation times for the following(More)
PURPOSE To evaluate proton magnetic resonance (MR) spectroscopic imaging with high spatial resolution for preoperative grading of suspected World Health Organization grades II and III gliomas. MATERIALS AND METHODS Institutional ethics committee approval and informed consent were obtained for control subjects but were not required for the retrospective(More)
The PermaSense project has set the ambitious goal of gathering real-time environmental data for high-mountain permafrost in unattended operation over multiple years. This paper discusses the specialized sensing and data recovery architecture tailored to meet the precision, reliability and durability requirements of scientists utilizing the data for model(More)
BACKGROUND AND PURPOSE The new 3.0-T imagers theoretically yield double the signal-to-noise ratio (SNR) and spectral resolution of 1.5-T instruments. To assess the possible improvements for multivoxel 3D proton MR spectroscopy (1H-MRS) in the human brain, we compared the SNR and spectral resolution performance with both field strengths. METHODS(More)
A large body of published work shows that proton (hydrogen 1 [(1)H]) magnetic resonance (MR) spectroscopy has evolved from a research tool into a clinical neuroimaging modality. Herein, the authors present a summary of brain disorders in which MR spectroscopy has an impact on patient management, together with a critical consideration of common data(More)