We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Spectrally selective bSSFP using off‐resonant RF excitations permits high spatiotemporal resolution 3D metabolic imaging of hyperpolarized [1‐<sup>13</sup>C]Pyruvate‐to‐[1‐<sup>13</sup>C]lactate conversion.
- Authors
Skinner, Jason G.; Topping, Geoffrey J.; Nagel, Luca; Heid, Irina; Hundshammer, Christian; Grashei, Martin; van Heijster, Frits H. A.; Braren, Rickmer; Schilling, Franz
- Abstract
Purpose: To develop a high spatiotemporal resolution 3D dynamic pulse sequence for preclinical imaging of hyperpolarized [1‐13C]pyruvate‐to‐[1‐13C]lactate metabolism at 7T. Methods: A standard 3D balanced SSFP (bSSFP) sequence was modified to enable alternating‐frequency excitations. RF pulses with 2.33 ms duration and 900 Hz FWHM were placed off‐resonance of the target metabolites, [1‐13C]pyruvate (by approximately −245 Hz) and [1‐13C]lactate (by approximately 735 Hz), to selectively excite those resonances. Relatively broad bandwidth (compared to those metabolites' chemical shift offset) permits a short TR of 6.29 ms, enabling higher spatiotemporal resolution. Bloch equation simulations of the bSSFP response profile guided the sequence parameter selection to minimize spectral contamination between metabolites and preserve magnetization over time. Results: Bloch equation simulations, phantom studies, and in vivo studies demonstrated that the two target resonances could be cleanly imaged without substantial bSSFP banding artifacts and with little spectral contamination between lactate and pyruvate and from pyruvate hydrate. High spatiotemporal resolution 3D images were acquired of in vivo pyruvate‐lactate metabolism in healthy wild‐type and endogenous pancreatic tumor‐bearing mice, with 1.212 s acquisition time per single‐metabolite image and (1.75 mm)3 isotropic voxels with full mouse abdomen 56 × 28 × 21 mm3 FOV and fully‐sampled k‐space. Kidney and tumor lactate/pyruvate ratios of two consecutive measurements in one animal, 1 h apart, were consistent. Conclusion: Spectrally selective bSSFP using off‐resonant RF excitations can provide high spatio‐temporal resolution 3D dynamic images of pyruvate‐lactate metabolic conversion.
- Subjects
THREE-dimensional imaging; BLOCH equations; LACTATES; LACTATION; KIDNEY tumors
- Publication
Magnetic Resonance in Medicine, 2023, Vol 90, Issue 3, p894
- ISSN
0740-3194
- Publication type
Article
- DOI
10.1002/mrm.29676