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Magnetic resonance (MR) spectroscopy and imaging experiments on humans were performed with a whole-body MR system at a static field of 4 tesla. Spectroscopic studies focussed on 1H, 13C, and 31P. Imaging of humans turned out to be possible, although below the optimum at this field. This holds especially for body imaging, since RF penetration effects and(More)
Sixteen patients with prediagnosed cerebral lesions were studied with stimulated echo localized 1H-spectroscopy at 4 Tesla. Initially, CT cerebral angiography and MR investigation at 1.5 Tesla were performed. After selecting a patient and receiving his agreement the high field examination started with the acquisition of an MR image of the known tumor at 4(More)
We have applied a new method for separating water and fat resonances in proton magnetic resonance (MR) imaging to human studies using a whole-body MR imaging system at 2.0 T. Chemical shift selective (CHESS) MR imaging provides either a water or fat image in a single experimental run within the same time needed for a conventional composite image. Although(More)
Recently, stimulated echo acquisition mode (STEAM) magnetic resonance (MR) imaging has been demonstrated as a new tool for multiparametric MR imaging studies. Applications of the chemical shift selective (CHESS) STEAM technique using a 2.0-T whole-body MR imaging system are reported in which a series of contiguous cross-sectional images of the head and the(More)
The introduction of STEAM (stimulated echo acquisition mode) magnetic resonance (MR) sequences provides access to a variety of MR parameters. T1-weighted and calculated T1 proton MR images of the head of healthy volunteers and a patient with an astrocytoma are presented. MR examinations were performed with a 2.0-T whole-body system. The STEAM T1 method can(More)
In vivo 13C spectroscopy experiments were performed using a whole-body MR system at a static field of 4 T. The main goal of the investigations was to evaluate the sensitivity increase achievable by means of 13C/1H double-resonance techniques at 4 T. Spectra from subcutaneous fat as well as muscle glycogen from the lower leg were acquired using frequency(More)
A bridge type superhet spectrometer for time resolved investigation of rotational relaxation is described. Allowing the application of both Starkand pump-modulation techniques the arrangement may be used for single and double resonance experiments, showing a lot of advantages compared with a conventional Starkor double resonance-spectrometer. These features(More)
Transient experiments in gas phase microwave spectroscopy have been developed in the past few years to investigate molecular rotational relaxation processes [1]. The information on bulk relaxation data obtained from these studies may be useful to understand molecular collision dynamics and thereby the intermolecular potential. Such information has also(More)
X-ray diffraction is investigated in the supercooled region (263-273 K) and, for comparison, at ambient conditions. By means of an energy-dispersive set-up coherent x-ray scattering cross sections within a wide range of momentum transfer values are monitored simultaneously using in-house laboratory equipment. The data are corrected for the energy-dependent(More)
A four-level double resonance method has been developed allowing the determination of the relative collision induced change in signal intensity rj without application of the Stark modulation technique. The method is based on certain properties of the bridge type superheterodyne spectrometer and may be applied to molecular transitions showing strong(More)
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