Standardization of T1-mapping in cardiovascular magnetic resonance using clustered structuring for benchmarking normal ranges

•Normal myocardial T1 values vary widely across different MOLLI T1-mapping methods.•Clustered structuring via an online calculator is practical for T1 standardization.•Clustered structuring allows benchmarking of local norms against published norms.•Clustered structuring increases confidence and quality in T1-mapping implementation.