Fig 1. T1MES phantom used in this study, and the reproducibility study protocol.

a) The T1MES phantom used in this study consists of 9 vials of NiCl₂ doped agarose covering T₁ and T₂ ranges in the blood and myocardium before and after Gadolinium-based contrast agents. b) An imaging session was repeated every 2–3 weeks over 20 months (between-session reproducibility). Within each session, slice-interleaved T₁ and T₂ mapping sequences were repeated 3 times (between-repetition repeatability) for five slices (between-slice repeatability). SE T₁ and T₂ measurements and MOLLI were performed for comparison. STONE-bSSFP, slice-interleaved T₁ with balanced steady‐state free precession; STONE-GRE, slice-interleaved T₁ with spoiled gradient echo; SE, spin-echo.