Longitudinal Tρ quantification in chronic hepatitis B: from fibrosis staging to pegylated interferon-α therapeutic response tracking.

Rationale And Objectives: To investigate liver tissue alterations across chronic hepatitis B (CHB) progression stages and monitor therapeutic changes following pegylated interferon-α (PEG-IFNα) therapy using Tρ magnetic resonance imaging (MRI).

Materials And Methods: This prospective study enrolled 93 CHB patients stratified by histological severity: 44 mild, 26 moderate, and 23 severe cases. All patients underwent liver biopsy and Tρ MRI at baseline, followed by 48 weeks of PEG-IFNα therapy. 36 patients completed post-treatment Tρ MRI. A control cohort of 23 healthy volunteers received baseline MRI scans. Hepatic Tρ relaxation times were compared across subgroups and correlated with histopathological parameters (inflammation grade, fibrosis stage), serum biomarkers (alanine aminotransferase [ALT], aspartate aminotransferase [AST], total bilirubin [TBIL], direct bilirubin [DBIL], cholinesterase [CHE]), and non-invasive indices (fibrosis-4 index [FIB-4]). Statistical analyses included Spearman's correlation and linear regression.

Results: The mild CHB group showed elevated Tρ relaxation time (43.94 ± 4.88 ms) versus healthy controls (39.05 ± 3.07 ms; P = 0.028), with progressive increases in moderate (48.21 ± 5.78 ms; P = 0.022 vs mild) and severe subgroups (53.99 ± 5.78 ms; P < 0.001 vs moderate). All patient groups differed significantly from controls (all P < 0.001). Tρ relaxation times exhibited strong positive correlations with histopathological progression (R = 0.77 for fibrosis stage, R = 0.50 for inflammation grade; both P < 0.001) and moderate correlations with liver function parameters (ALT: R = 0.18; AST: R = 0.21) and synthetic markers (CHE: R = 0.24). Post-therapeutic Tρ values decreased significantly compared to baseline (48.99 ± 8.05 ms vs. 43.57 ± 7.20 ms, P = 0.014).

Conclusion: Tρ MRI provides a promising non-invasive tool for assessing liver disease severity and monitoring treatment-related changes in CHB patients.