Liver Tissue Mapping in Transfusion-Dependent β-Thalassemia: Reproducibility and Clinical Insights from Multiparametric MRI

<b>Background/Objectives</b>: We measured hepatic T2*, T1, and T2 values in <i>N</i> = 81 transfusion-dependent thalassemia (TDT) patients to assess and compare their reproducibility, evaluate their correlations with demographics and clinical parameters, and explore their association with disease-related complications. <b>Methods:</b> All TDT patients (52 females, 38.13 ± 10.79 years), were enrolled in the Extension-Myocardial Iron Overload in Thalassaemia Network. The magnetic resonance imaging protocol (1.5 T) included: multi-echo gradient echo sequences for T2* relaxometry, modified look-locker inversion recovery (MOLLI) sequences for T1 mapping, and multi-echo fast-spin-echo (MEFSE) sequences for T2 mapping. <b>Results:</b> All three relaxation times demonstrated good intra- and inter-observer reproducibility and were significantly correlated with each other. Of the 59 patients with reduced T2*, 45 (76.3%) also had reduced T1, and 42 (71.2%) had reduced T2 values. Among 22 patients with normal T2*, 3 (13.6%) exhibited reduced T1. No patients showed increased T1, and only one had elevated T2. Liver relaxation times were not associated with gender or splenectomy status. All relaxation times inversely correlated with serum ferritin levels, while T2 and T2* inversely correlated with mean alanine aminotransferase levels. Cirrhosis and glucose metabolism alterations were associated with lower relaxation times. All three relaxation times effectively discriminated between the absence and presence of cirrhosis [areas under the curve (AUCs) with 95% confidence intervals (CIs): 0.85 (0.75-0.92) for T2*, 0.78 (0.68-0.87) for T1, and 0.92 (0.84-0.97) for T2]. T2* showed comparable accuracy to T1 and T2, while a significant difference was observed between T1 and T2 values. All liver relaxation times demonstrated similar diagnostic performance in identifying glucose metabolism alterations [AUCs with 95% CIs: 0.67 (0.55-0.77) for T2*, 0.69 (0.57-0.79) for T1, and 0.67 (0.56-0.77) for T2]. <b>Conclusions:</b> In TDT, a comprehensive assessment of hepatic relaxation times may enhance clinical monitoring and management of iron overload and its related complications.