Correction of Frequency Drifts Induced by Gradient Heating in 1H Spectra Using Interleaved Reference Spectroscopy

Thomas Lange¹, Maxim Zaitsev¹, Martin Buechert¹

Long MRI measurements utilizing high gradient duty cycle can heat up the passive shim elements of the MR system giving rise to frequency drifts in subsequent MRS experiments. The interleaved reference scan (IRS) method is used for correcting these frequency drifts in 1H spectra in vitro and in vivo. IRS implies the acquisition of an additional water reference spectrum after every spectral average. The line widths of the spectral resonances can be largely reduced using the reference signal for phase correction. This may improve peak resolution and SNR considerably, allowing a more valid data analysis in clinical studies.