Minimum echo time PRESS-based proton observed carbon edited (POCE) MRS in rat brain using simultaneous editing and localization pulses

Magn Reson Med. 2018 Oct;80(4):1279-1288. doi: 10.1002/mrm.27119. Epub 2018 Feb 9.


Purpose: Indirect 13 C MRS by proton-observed carbon editing (POCE) is a powerful method to study brain metabolism. The sensitivity of POCE-MRS can be enhanced through the use of short TEs, which primarily minimizes homonuclear J-evolution related losses; previous POCE-MRS implementations use longer than optimal echo times due to sequence limitations, or short TE image selected in vivo spectroscopy-based multi-shot acquisitions for 3D localization. To that end, this paper presents a novel single-shot point resolved spectroscopy (PRESS)-localized POCE-MRS sequence that involves the application of simultaneous editing and localization pulses (SEAL)-PRESS, allowing the TE to be reduced to a theoretically optimal value of ∼ 1/JHC .

Methods: The optimized SEAL-PRESS sequence was first evaluated in simulation and in phantom; next, the sequence was validated with dynamic in vivo POCE-MRS performed in a rat preparation during a 1,6-13 C2 -Glc infusion, and on a microwave fixed rat brain following a 2-hour [1,6-13 C2 ]-Glc infusion. POCE spectra from the SEAL-PRESS sequence were compared against a previously described 12.6-ms PRESS-POCE sequence utilizing a classical carbon editing scheme.

Results: The SEAL-PRESS sequence provides > 95% editing efficiency, optimal sensitivity, and localization for POCE MRS with an overall sequence TE of 8.1 ms. Signal amplitude of 13 C-labeled metabolites Glu-H4, Gln-H4, Glx-H3, Glc-H6 +Glx-H2, and Asp-H2 were shown to be improved by >17% relative to a 12.6-ms PRESS-POCE sequence in vivo.

Conclusion: We report for the first time, a single-shot PRESS-localized and edited 8.1-ms TE POCE-MRS sequence with optimal sensitivity, editing efficiency, and localization.

Keywords: 1H-[13C] MRS; POCE; SEAL-PRESS; [1,6-13C2] glucose infusion; localized 13C edited MRS; short TE.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / diagnostic imaging*
  • Brain / metabolism*
  • Brain Chemistry / physiology
  • Carbon-13 Magnetic Resonance Spectroscopy / methods*
  • Glucose / administration & dosage
  • Glucose / chemistry
  • Glucose / pharmacokinetics
  • Image Processing, Computer-Assisted / methods*
  • Male
  • Phantoms, Imaging
  • Rats
  • Rats, Long-Evans


  • Glucose