• Proceedings of the Korean Society of Medical Physics Conference
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• 2005.04a
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• pp.93-95
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• 2005

MRS is to measure very small metabolite signals, whose resonant frequencies spread over the chemical shift range characteristic of the measured nucleus. The MR signal originates from the excited volume, which is a column of tissue divided into slices by gradient or rf encoding. The parameters that acquired data affected by TE, TR, and other variables. The higher spatial resolution of 3D CSI compared to SVS and its ability to examine regional metabolite variations for brain study.

• Investigative Magnetic Resonance Imaging
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• v.12 no.1
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• pp.27-32
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• 2008

Purpose : We developed a 3D CSI (chemical shift imaging) sequence that uses the PRESS (point resolved spectroscopy) excitation scheme and spiral-based readout gradients. Materials and Methods : We implemented constant-density spirals ($32{\times}32$ matrix, $24{\times}24\;cm$ FOV) which use analytic equations to enable real-time prescription on the scanner. In-vivo data from the brain were collected and reconstructed using the gridding algorithm. Results : Data illustrate that with our imaging sequence, the benefits of the PRESS technique, which include elimination of lipid artifacts, remain intact while flexible scan time versus resolution tradeoffs can be achieved using the constant-density spirals. Volumetric high resolution 3D CSI covering 5760 cm3 could be obtained in 12.5 minutes. Conclusion : Spiral-based readout gradients offer a flexible tradeoff between scan time versus resolution. By combining this feature with PRESS based excitation, efficient methods of volumetric spectroscopic imaging can be accomplished by obtaining whole brain coverage while eliminating lipid contamination.