Feedback-Based Interleaved Reference Spectroscopy

Thomas Lange¹, Martin Buechert¹, Maxim Zaitsev¹

Magnetic resonance spectroscopy experiments can be severely affected by frequency drifts, for example when a spectroscopy scan is run right after an imaging experiment involving a high gradient duty cycle. In this work we propose a feedback-based interleaved reference scan (IRS) method which updates the carrier frequency of RF pulses and ADCs in real time, using water reference spectra acquired in an interleaved fashion. Compared to a frequency lock using the residual water peak in the actual spectrum, the proposed method is more robust, particularly in the presence of strong lipid contamination. Additionally, it allows for retrospective phase correction.