Lactate saturation limits bicarbonate detection in hyperpolarized 13 C ‐pyruvate MRI of the brain

Autor: Nikolaj Bøgh, James T. Grist, Camilla W. Rasmussen, Lotte B. Bertelsen, Esben S. S. Hansen, Jakob U. Blicher, Damian J. Tyler, Christoffer Laustsen
Rok vydání: 2022
Předmět:
Zdroj: Bøgh, N, Grist, J T, Rasmussen, C W, Bertelsen, L B, Hansen, E S S, Blicher, J U, Tyler, D J & Laustsen, C 2022, ' Lactate saturation limits bicarbonate detection in hyperpolarized 13 C-pyruvate MRI of the brain. ', Magnetic Resonance in Medicine . https://doi.org/10.1002/mrm.29290
Bøgh, N, Grist, J T, Rasmussen, C W, Bertelsen, L B, Søvsø Szocska Hansen, E, Blicher, J, Tyler, D J & Laustsen, C 2022, ' Lactate saturation limits bicarbonate detection in hyperpolarized 13 C-pyruvate MRI of the brain ', Magnetic Resonance in Medicine, vol. 88, no. 3, pp. 1170-1179 . https://doi.org/10.1002/mrm.29290
Bøgh, N, Grist, J T, Rasmussen, C W, Bertelsen, L B, Hansen, E S S, Blicher, J U, Tyler, D J & Laustsen, C 2022, ' Lactate saturation limits bicarbonate detection in hyperpolarized 13 C-pyruvate MRI of the brain ', Magnetic Resonance in Medicine, vol. 88, no. 3, pp. 1170-1179 . https://doi.org/10.1002/mrm.29290
ISSN: 1522-2594
0740-3194
Popis: Purpose: To investigate the potential effects of [1- 13C]lactate RF saturation pulses on [ 13C]bicarbonate detection in hyperpolarized [1- 13C]pyruvate MRI of the brain. Methods: Thirteen healthy rats underwent MRI with hyperpolarized [1- 13C]pyruvate of either the brain (n = 8) or the kidneys, heart, and liver (n = 5). Dynamic, metabolite-selective imaging was used in a cross-over experiment in which [1- 13C]lactate was excited with either 0° or 90° flip angles. The [ 13C]bicarbonate SNR and apparent [1- 13C]pyruvate-to-[ 13C]bicarbonate conversion (k PB) were determined. Furthermore, simulations were performed to identify the SNR optimal flip-angle scheme for detection of [1- 13C]lactate and [ 13C]bicarbonate. Results: In the brain, the [ 13C]bicarbonate SNR was 64% higher when [1- 13C]lactate was not excited (5.8 ± 1.5 vs 3.6 ± 1.3; 1.2 to 3.3–point increase; p = 0.0027). The apparent k PB decreased 25% with [1- 13C]lactate saturation (0.0047 ± 0.0008 s −1 vs 0.0034 ± 0.0006 s −1; 95% confidence interval, 0.0006–0.0019 s −1 increase; p = 0.0049). These effects were not present in the kidneys, heart, or liver. Simulations suggest that the optimal [ 13C]bicarbonate SNR with a TR of 1 s in the brain is obtained with [ 13C]bicarbonate, [1- 13C]lactate, and [1- 13C]pyruvate flip angles of 60°, 15°, and 10°, respectively. Conclusions: Radiofrequency saturation pulses on [1- 13C]lactate limit [ 13C]bicarbonate detection in the brain specifically, which could be due to shuttling of lactate from astrocytes to neurons. Our results have important implications for experimental design in studies in which [ 13C]bicarbonate detection is warranted.
Databáze: OpenAIRE
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