Cardiac magnetic resonance parametric mapping in patients with thalassemia: Clinical insights into native myocardial T1 mapping and its relationship with T2*. A systematic review.

Myocardial iron overload represents a major cause of cardiac morbidity in patients with thalassemia. Cardiovascular magnetic resonance (CMR) T2* is the current reference for noninvasive myocardial iron quantification; however, it may be limited in detecting early iron-related myocardial changes. Native T1 mapping emerged as a complementary technique that may overcome some of the T2* limitations. The aim of this review is to analyze the available evidence on the use of native T1 mapping in thalassemia patients and to evaluate its relationship with T2*. Literature search was performed in PubMed, Scopus, Embase, and Cochrane. Studies evaluating myocardial T1 mapping in thalassemia patients were included. Data extraction focused on study characteristics, technical aspects, T1 and T2* values, and associations between the two measures. Sixteen studies were included. Most investigations reported a good relationship between T1 and T2* values. The strength of this association was higher in iron-overloaded cohorts and weaker in patients with normal T2*. Several studies described a subset of patients with reduced T1 despite normal T2*. Considerable heterogeneity was observed across studies in acquisition protocols, region of interest strategies and native T1 reference values. In conclusion, T1 mapping shows a global, though heterogeneous, association with T2* in thalassemia patients and its systematic integration in acquisition protocols represents a valuable complementary tool to T2*. Native T1 mapping may improve detection of early myocardial iron-related changes and support individualized patient management. Prospective longitudinal studies incorporating clinical outcomes are required to define the prognostic value and clinical role of T1 mapping.