Left sidebar menu
Navigation menu
Page Content
Nuclear Magnetic Resonance Unit
Group Leader |
|||||||||||||||||
|
The NMR Unit is primarily engaged in the development and adaptation of novel magnetic resonance (MR) methods and research into the fundamental biophysics underlying neuroimaging contrast. We are particularly interested in contrast mechanisms that can be exploited for functional MR imaging (fMRI), mapping of perfusion by arterial spin labeling, and quantitative structural imaging. Pure methodological research besides imaging sequence development also comprises in-house construction of hardware including multi-channel radiofrequency (RF) coils and stimulation devices for fMRI. Support and sophistication of the MR infrastructure ensures that functional and structural MR studies performed at the Institute reflect the current state of the art.
To achieve these ends, the NMR Unit operates two human-scale 3T systems.
A Siemens MAGNETOM Trio scanner was installed in 2003 and upgraded to a TIM system in April 2008. The actively shielded magnet has an open bore diameter of 60 cm. Spatial information is encoded by a whole-body gradient system producing gradients of up to 45 mT/m within 225 µsec. The resonance frequency in imaging experiments with hydrogen is 123.2 MHz. A second broad-banded RF channel is available for MR experiments with nuclei other than hydrogen. A variety of RF coils permits all kinds of investigations of the human brain with up to 32 parallel receive channels.
A Bruker MedSpec 30/100 scanner was installed in the summer of 1996 as one of the first of its kind. The open bore of the superconducting magnet has an inner diameter of 55 cm. The stray field is restricted by 180 tons of steel embedded in the walls of the magnet room. The whole-body gradient set is capable of switching 45 mT/m within 320 µsec. Signal acquisition and RF transmission are generally performed at a hydrogen resonance frequency of 125.3 MHz using a quadrature birdcage resonator or custom-built RF coils. The amplifier can produce RF pulses with up to 5 kW. Additional RF cannels permit experiments with nuclei other than hydrogen. The system is routinely being used for fMRI and perfusion studies.
|
||||||||||||||||
Science |
|
||||||||||||||||
Footer
