In Vivo Measurement of Taurine With Optimized Double-Quantum Filtering Magnetic Resonance Spectroscopy

To enhance the accuracy and reproducibility for in vivo taurine quantification using the double-quantum filtering (DQF) technique.

Simulations and phantom experiments were conducted at both 7 T and 3 T to determine the optimal parameter τ by calculating the taurine purity index among other neighboring metabolites. The frequency-selective read-pulse bandwidth and the dephasing/rephasing gradient moments were further adjusted to reduce residual water side band interference. Rat models of C6 gliomas were compared to normal brain for taurine level at 7 T. Metabolomics was conducted to validate the accuracy of taurine quantification. Human gray and white matter taurine differences were revealed at 3 T. Test-retest reliability was evaluated on humans.

Simulations and phantom experiments identified optimal τ for maximizing taurine signal purity as 102 ms at 7 T and 92 ms at 3 T. The best combinations of parameters for minimal water interference were determined at 3 T. Optimized DQF sequences yielded lower CRLBs. In rat brains, taurine concentration measured with optimized DQF sequences exhibited strong correlation with metabolomics, outperforming both conventional MRS and nonoptimized DQF sequences. Only the optimized method revealed significant taurine concentration differences between gray and white matter. Test-retest demonstrated good reproducibility in gray matter (ICC = 0.82) for the optimized method.

The optimized DQF method enhances taurine detection accuracy and robustness in both animal and human studies and was for the first time applied in human brain taurine test at 3 T.