Simultaneous two-voxel localized 1H-observed 13C-edited spectroscopy for in vivo MRS on rat brain at 9.4T: Application to the investigation of excitotoxic lesions

PRESS timings for resolving 13C4‐glutamate 1H signal at 9.4 T: Demonstration in rat with uniformly labelled 13C‐glucose

“…Measuring brain 13 C 4 ‐Glu with MRS during an infusion of a 13 C‐labelled substrate such as [U‐ 13 C 6 ]‐Glc provides a measure of V TCA from the Glu C4 FE time course . Such measures have been performed in rat brain at 9.4 T . Techniques that require system multinuclear capability were used.…”

“…Indirect 13 C studies at 9.4 T have primarily involved POCE based techniques; however, our approach is closer to that of Ref. .…”

In vivo proton observed carbon edited (POCE) 13C magnetic resonance spectroscopy of the rat brain using a volumetric transmitter and receive‐only surface coil on the proton channel

“…Usage of a 1 H volumetric resonator accommodates the realization of a PRESS-localized POCE sequence with highly uniform spin nutation with conventional pulses. With little or no modifications, the proposed 1 H-[ 13 C] coil platform is expected to provide excellent localization and uniform nutation when paired with POCE sequences using conventional pulse such as: PRESS-POCE (described here and elsewhere; 4,20), ACED-STEAM based POCE (7), and SPECIAL based POCE (8). Furthermore, the coil platform is compatible with spinecho and gradient-echo based imaging sequences using conventional pulses (due to the B þ 1 field homogeneity relative to an all-surface coil 1 H-13 C MRS coil approach), thus providing the convenience of using optimized and established functional imaging sequences during 1 H-13 C MRS studies.…”

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

“…However, POCE via this scheme typically necessitates the final echo to be >10 ms to accommodate 2 nonsimultaneously employed and pulses and the ms delay. 2) Employ and refocusing pulses on alternate scans, centered ms before a ms echo, reported for image‐selected in vivo spectroscopy (ISIS), PRESS, and LASER implementations . This approach can reduce the sequence TE relative to approach 1 due to the simultaneous use of editing and refocusing.…”

“…LASER‐POCE sequences reported have TE >22 ms, primarily due to the requirement for 3 pairs of ∼1 ms adiabatic full passage (AFP) pulses and an ∼10 ms final echo; however, the effects of homonuclear J‐evolution and diffusion are minimized for LASER‐POCE due to the Carr‐Purcell spin‐echo character of the sequence, and chemical shift displacements are minimal due to the high bandwidth (BW) AFP pulses (relative to purely amplitude modulated pulses) used. PRESS‐POCE sequences have been implemented with TE < 16 ms, which is an attractive alternative to LASER and multi‐shot ISIS‐based implementations, provided that a spatially homogenous field is present.…”