Spectroscopic imaging with prospective motion correction and retrospective phase correction

Abstract

Motion-induced artefacts in magnetic resonance spectroscopic imaging are much harder to recognize than in imaging experiments and can therefore lead to erroneous interpretation. A method for prospective motion correction based on an optical tracking system has recently been proposed and has already been successfully applied to single voxel spectroscopy. In this work, the utility of prospective motion correction in combination with retrospective phase correction is evaluated for spectroscopic imaging in the human brain. Retrospective phase correction, based on the interleaved reference scan method, is used to correct for motion-induced frequency shifts and ensure correct phasing of the spectra across the whole spectroscopic imaging slice. It is demonstrated that the presented correction methodology can reduce motion-induced degradation of spectroscopic imaging data.

Real-time motion- and B0-correction for LASER-localized spiral-accelerated 3D-MRSI of the brain at 3T

“…Several groups have found significantly improved MRS data quality, if motion correction was applied (Andrews-Shigaki et al, 2011; Boer et al, 2012; de Nijs et al, 2009; Ernst and Li, 2011; Helms and Piringer, 2001; Hess et al, 2012; Hess et al, 2011; Keating and Ernst, 2012; Kim et al, 2004; Lange et al, 2012; Lin et al, 2009; Posse et al, 1993; Thiel et al, 2002; Zaitsev et al, 2010). A common approach is the retrospective correction of frequency and phase, in particular for SVS (Ernst and Li, 2011; Helms and Piringer, 2001; Lin et al, 2009).…”

“…Several studies have reported significantly improved spectral quality for both single-voxel spectroscopy (SVS) and 2D-MRSI, when retrospective, prospective, or a combination of both motion corrections is used (Andrews-Shigaki et al, 2011; Boer et al, 2012; de Nijs et al, 2009; Ernst and Li, 2011; Hess et al, 2012; Hess et al, 2011; Keating and Ernst, 2012; Lange et al, 2012; Lin et al, 2009; Thiel et al, 2002; Zaitsev et al, 2010). While retrospective correction alone (e.g., frequency/phase alignment of separately saved averages) can improve data quality to a certain degree (Helms and Piringer, 2001; Kim et al, 2004; Posse et al, 1993), prospective real-time motion correction (i.e., updating the MR sequence in real-time) can further improve data quality (Andrews-Shigaki et al, 2011; Hess et al, 2012; Hess et al, 2011; Lange et al, 2012; Zaitsev et al, 2010).…”

“…While retrospective correction alone (e.g., frequency/phase alignment of separately saved averages) can improve data quality to a certain degree (Helms and Piringer, 2001; Kim et al, 2004; Posse et al, 1993), prospective real-time motion correction (i.e., updating the MR sequence in real-time) can further improve data quality (Andrews-Shigaki et al, 2011; Hess et al, 2012; Hess et al, 2011; Lange et al, 2012; Zaitsev et al, 2010). …”

“…There are three conceptually different real-time motion-tracking approaches that can be used for prospective correction: 1) optical tracking (Andrews-Shigaki et al, 2011; Lange et al, 2012; Zaitsev et al, 2010); 2) active markers (Ooi et al, 2009); and 3) MR navigators (Hess et al, 2012; Hess et al, 2011; Thiel et al, 2002). To date, only optical tracking and MR navigators have been used for MRS motion correction.…”

Motion artifacts in MRI: A complex problem with many partial solutions

“…The topic of prospective motion correction has gained popularity in the last few years resulting in numerous new applications including fMRI (101, 102), DWI (103, 104), and spectroscopy (105-107). Although it is an extremely promising approach for neuroimaging, it does have some limitations, including practical considerations (e.g., marker fixation for external tracking systems) and uncorrectable effects (e.g., motion-related B0 distortions (108)).…”