Diagnostic Value of Native T1 and T2 Mapping in Differentiating Clinically Suspected Amyloidosis and Hypertrophic Cardiomyopathy

Background/Objectives: Differentiating clinically suspected cardiac amyloidosis from hypertrophic cardiomyopathy (HCM) remains a significant clinical challenge, especially when contrast-enhanced imaging is contraindicated. This study evaluated the potential diagnostic utility of non-contrast cardiac MRI parameters, specifically native T1 and T2 mapping, as supportive indicators in this differential diagnosis. Methods: This retrospective single-center study included 20 patients with clinically suspected amyloidosis (based on combined clinical and echocardiographic assessment), 20 patients with HCM, and 20 healthy controls. Cine imaging and native T1/T2 mapping were analyzed. Myocardial, blood-pool, and liver T1/T2 values, along with morphological parameters, were recorded. N-terminal pro–B-type natriuretic peptide (NT-proBNP) and troponin levels, when available, were documented retrospectively for descriptive purposes. Receiver operating characteristic (ROC) analyses were performed to assess the discriminatory performance of imaging parameters. Results: Patients in the suspected amyloidosis group demonstrated significantly higher myocardial, blood-pool, and liver T1 values, as well as higher myocardial T2 values, compared with both the HCM and control groups (p < 0.001). Myocardial T1 showed strong discriminatory performance for differentiating suspected amyloidosis from controls (cut-off 1061 ms, AUC = 0.975). In distinguishing suspected amyloidosis from HCM, blood-pool T1 (AUC = 0.900) and myocardial T1 (AUC = 0.938) provided the highest diagnostic performance. Additionally, elevated NT-proBNP (>1000 pg/mL in 93% of tested cases) and troponin levels were observed in the suspected amyloidosis group, consistent with increased myocardial stress. Conclusions: Native T1 and T2 mapping may offer valuable supportive information in differentiating clinically suspected amyloidosis from HCM on non-contrast MRI. Myocardial and blood-pool T1 values appear to provide complementary tissue characterization, which may be particularly useful when gadolinium administration or invasive procedures are not feasible. These findings suggest a role for non-contrast mapping in the diagnostic workup but require further validation in larger, biopsy-confirmed multicenter cohorts.