Quantitative MR biomarkers in identifying steatohepatitis and fibrosis associated with metabolic dysfunction...

Liver biopsy is the gold standard for diagnosing metabolic dysfunction associated steatohepatitis (MASH). There is an unmet need for non-invasive tests to differentiate uncomplicated hepatic steatosis from steatohepatitis and fibrotic MASH.

We aimed to evaluate the role of T1 relaxation time, MRI-PDFF (Proton density fat fraction), and IVIM (Intravoxel Incoherent motion) in detecting and differentiating MASH from non-MASH group of patients and fibrotic MASH from low-risk/absent MASH group.

We prospectively conducted a cross-sectional study of 64 patients with Metabolic dysfunction associated steatotic liver disease (MASLD) and reviewed MRI data from 46 patients who underwent liver biopsy. Dedicated sequences were performed using a 1.5 T MR scanner to derive liver MRI-PDFF, T1, and IVIM values (D-True diffusion coefficient, D*- pseudo diffusion coefficient, and f - perfusion fraction). The NASH CRN (Clinical Research Network) scoring system was used to categorize patients based on biopsy results. MR-derived data were compared with the biopsy results.

Median T1 values were significantly higher in patients with MASH than the non-MASH group (884.97 ms versus 698.59 ms; p = 0.0002, AUROC (95% CI) 0.828 (0.709-0.947)) and in fibrotic MASH versus low-risk/absent MASH group (870.48 ms versus 695.10 ms; p < 0.0001, AUROC (95% CI) 0.851 (0.742-0.961)). Median MRI-PDFF values were significantly higher in MASH patients compared to non-MASH patients (19.38% vs. 9.46%, p = 0.0004, AUROC (95% CI) 0.808 (0.657-0.937)) and in fibrotic MASH compared to low-risk/absent MASH (20.45% vs. 8.58%, p = 0.0001, AUROC (95% CI) 0.847 (0.730-0.963)). MASH patients showed significantly lower D* (p = 0.0167) and f (p = 0.0382) than the non-MASH group; fibrotic MASH patients had lower D (p = 0.042) and D* (p = 0.025) than the low-risk/absent MASH group. MRI T1 mapping and MRI-PDFF demonstrate good diagnostic accuracy for detecting biopsy-defined MASH and fibrotic MASH. Further large-scale, multicenter studies are required to establish their role in clinical practice and potentially help reduce reliance on liver biopsy.