Quantitative equivalence of Quantitative Imaging Biomarkers Alliance (QIBA)-2023- and QIBA-2020-compliant MR...

Magnetic resonance elastography (MRE) has become an essential noninvasive tool for quantitative assessment of liver stiffness and fibrosis staging, particularly in patients with steatotic liver disease. To enhance standardization and reproducibility, the Quantitative Imaging Biomarkers Alliance (QIBA) released an updated liver MRE profile in 2023, replacing the previous 2020 version. However, the quantitative continuity between these two protocol versions, particularly for longitudinal liver stiffness measurements, has not been sufficiently validated. This study aimed to evaluate the quantitative equivalence and clinical utility of a QIBA-2023-compliant MRE protocol through direct comparison with the conventional QIBA-2020-compliant protocol in the same subjects, with emphasis on longitudinal liver stiffness assessment and image quality.

This retrospective study included 130 consecutive patients who underwent liver MRE in 2024. Each patient was examined using both the conventional QIBA-2020-compliant protocol and the updated QIBA-2023-compliant protocol during a single imaging session. Liver stiffness values were compared using Spearman correlation, Bland-Altman analysis, and intraclass correlation coefficients (ICC). Measurement variability and repeatability were evaluated with reference to QIBA-defined repeatability metrics. Image quality was evaluated by comparing region-of-interest (ROI) size and measurable liver parenchymal area excluding low-confidence (cross-hatched) regions.

Mean liver stiffness values were 3.62 ± 1.81 kPa for the conventional protocol and 3.69 ± 1.94 kPa for the updated protocol, with a very strong correlation (r = 0.98, p < 0.001) and excellent agreement (ICC = 0.988). Bland-Altman analysis showed a minimal mean bias of 0.07 kPa with 95% limits of agreement from - 0.48 to 0.63 kPa, which were within established MRE repeatability thresholds. Although the difference between protocols reached statistical significance, the absolute difference was not clinically meaningful. The updated protocol produced significantly larger ROIs and a greater measurable liver parenchymal area, consistent with reduced imaging artifacts and improved image quality.

The QIBA-2023-compliant MRE protocol demonstrates quantitative equivalence to the conventional QIBA-2020 protocol while offering improved artifact suppression and expanded measurable liver parenchyma. These findings support use of the updated protocol for reliable longitudinal liver stiffness assessment without compromising diagnostic performance.