Spiral imaging artifact reduction: a comparison of two k-trajectory measurement methods.

Purpose: To compare an external sensor-based k-space calibration technique with a routine precalibration method for quantification of method accuracy and reduction of spiral imaging artifacts to obtain improved image quality.

Materials And Methods: Recently, magnetic field monitoring (MFM) has been introduced as a new calibration technique of gradient field-related imperfections. External sensors are placed near the observed object to measure magnetic field variations during image acquisition.

Proton MR spectroscopy of the brain at 3 T: an update.

Proton magnetic resonance spectroscopy ((1)H-MRS) provides specific metabolic information not otherwise observable by any other imaging method. (1)H-MRS of the brain at 3 T is a new tool in the modern neuroradiological armamentarium whose main advantages, with respect to the well-established and technologically advanced 1.5-T (1)H-MRS, include a higher signal-to-noise ratio, with a consequent increase in spatial and temporal resolutions, and better spectral resolution.