Abstract
Spectral quality in 1H magnetic resonance spectroscopic imaging (MRSI) critically depends on the stability of the main magnetic field. For echo-planar MRSI implemented at 3 T, temperature variation in the passive steel shims of the magnet system can lead to a significant drift in the resonance frequency. A method is presented that incorporates interleaved measurement of the instantaneous resonance frequency of a reference water signal into a volumetric MRSI sequence and allows correction for the drift during postprocessing. Results from normal human brain at 3 T indicate that the correction largely removes lineshape distortions, recovers metabolite signal loss, and improves spectral quality by reducing the width of spectral lines; however, particularly in inferior regions, other sources of distortion may be present that cause broadening of spectral lines.
Original language | English (US) |
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Pages (from-to) | 465-469 |
Number of pages | 5 |
Journal | Magnetic Resonance in Medicine |
Volume | 53 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2005 |
Keywords
- Brain
- EPSI
- Frequency drift
- In vivo MR spectroscopic imaging
- Instrumental instabilities
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Radiological and Ultrasound Technology