BACKGROUND: With the increasing need for accurate liver disease diagnostics, non-invasive imaging techniques with rapid and precise quantitative measurements need to be established. This study introduced and validated the application of simultaneous multi-relaxation-time imaging (TXI) for the quantitative assessment of liver tissue by simultaneously acquiring proton density fat fraction (PDFF), lateral relaxation rate (R2*), and longitudinal relaxation time (T1) maps. It aimed to compare the accuracy and consistency of TXI with established quantitative magnetic resonance imaging (MRI) techniques, such as three-dimensional variable flip angle (VFA) T1 mapping, and multi-point quantitative Dixon (qDixon), in healthy volunteers and patients diagnosed with non-alcoholic fatty liver disease (NAFLD). METHODS: A prospective cohort of 35 healthy volunteers (mean age: 52±13 years, 21 women) and nine NAFLD patients (mean age: 48±13 years, 6 women) underwent liver MRI using TXI, VFA T1 mapping, and qDixon sequences. Intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to assess inter-observer agreement and measurement consistency. Paired RESULTS: The ICCs for the TXI-derived T1, R2*, and PDFF in healthy volunteers were 0.985 [95% confidence interval (CI): 0.971-0.993], 0.999 (95% CI: 0.998-1.000), and 0.995 (95% CI: 0.990-0.997), respectively, indicating excellent agreement. The regression analysis revealed strong correlations between the TXI and reference MRI measurements for the T1 (R CONCLUSIONS: TXI offers a rapid and reliable method for the simultaneous acquisition of T1, R2*, and PDFF maps, and has high consistency with established quantitative MRI techniques. This approach has significant potential for non-invasive liver tissue characterization in clinical settings, particularly in the diagnosis and monitoring of conditions such as NAFLD.