A Case Study Analysis on Monte Carlo-Simulated Uncertainty Propagation in Absolute Quantification for in vivo 1H-MRS of the Human Brain

The effect of uncertainty propagation for absolute quantification performed on individual single-voxel in vivo 1H-MRS experiments has yet to be examined. In this case study, we conduct an uncertainty analysis using Monte Carlo simulations on two previously published studies with reported absolute concentrations of metabolites and macromolecules, each employing different field strengths, relative linewidths and internal references (e.g. total creatine, tissue-specific water). The uncertainty from 8 in vivo spectra is simulated and compared to CRLBs from Linear Combination Modeling. A multifold uncertainty increase is observed in both metabolites and macromolecules across datasets, demonstrating that the CRLB systematically overestimates quantification precision.