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Purpose: This study aims to show the viability of conducting three-dimensional (3D) myocardial perfusion quantification covering the entire heart using both GRE and bSSFP sequences with hyperpolarized HP001., Methods: A GRE sequence and a bSSFP sequence, both with a stack-of-spirals readout, were designed and applied to three pigs. The images were reconstructed using   13 $$ {}^{13} $$ C coil sensitivity maps measured in a phantom experiment. Perfusion was quantified using a constrained decomposition method, and the estimated rest/stress perfusion values from   13 $$ {}^{13} $$ C GRE/bSSFP and Dynamic contrast-enhanced MRI (DCE-MRI) were individually analyzed through histograms and the mean perfusion values were compared with reference values obtained from PET(   15 $$ {}^{15} $$ O-water). The Myocardial Perfusion Reserve Index (MPRI) was estimated for   13 $$ {}^{13} $$ C GRE/bSSFP and DCE-MRI and compared with the reference values., Results: Perfusion values, estimated by both DCE and   13 $$ {}^{13} $$ C MRI, were found to be lower than reference values. However, DCE-MRI's estimated perfusion values were closer to the reference values than those obtained from   13 $$ {}^{13} $$ C MRI. In the case of MPRI estimation, the   13 $$ {}^{13} $$ C estimated MPRI values (GRE/bSSFP: 2.3/2.0) more closely align with the literature value (around 3) than the DCE estimated MPRI value (1.6)., Conclusion: This study demonstrated the feasibility of 3D whole-heart myocardial perfusion quantification using hyperpolarized HP001 with both GRE and bSSFP sequences. The   13 $$ {}^{13} $$ C perfusion measurements underestimated perfusion values compared to the   15 $$ {}^{15} $$ O PET literature value, while the   13 $$ {}^{13} $$ C estimated MPRI value aligned better with the literature. This preliminary result indicates   13 $$ {}^{13} $$ C imaging may more accurately estimate MPRI values compared to DCE-MRI., (© 2024 The Author(s). Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Sevoflurane is the most widely used inhaled anesthetic. Environmental enrichment (EE) can reverse sevoflurane-induced learning and memory impairment in young mice. However, the mechanism by which EE elicits this effect is unclear. The peroxisome proliferator-activated receptor (PPAR) regulatory pathway plays a critical role in the regulation of inflammation in central nervous system diseases. In this study, we investigated whether EE attenuates sevoflurane-induced learning and memory disability via the PPAR signaling pathway. Six-day-old mice were treated with 3% sevoflurane for 2 hours daily from postnatal day 6 (P6) to P8. Then, the mice were treated with EE. The effects of sevoflurane on learning and memory function, PPAR-γ expression in the brain, and the numbers of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells and 5-bromodeoxyuridine-positive cells in the hippocampus were determined. Sevoflurane induced neuronal apoptosis and neurogenesis inhibition, which may impair learning and memory in young mice. Furthermore, sevoflurane downregulated PPAR-γ expression. Both EE and the PPAR-γ agonist, rosiglitazone, attenuated sevoflurane-induced neuronal apoptosis, neurogenesis inhibition, and learning and memory impairment. Our findings suggest that EE ameliorated sevoflurane-induced neurotoxicity and learning and memory impairment through the PPAR-γ signaling pathway. PPAR-γ may be a potential therapeutic target for preventing or treating sevoflurane-induced neurotoxicity.