MR extracellular volume mapping and non-contrast T1ρ mapping allow early detection of myocardial fibrosis in diabetic monkeys.

• Monkeys with T2DM exhibit increased ECV, T1ρ, and mFI values, which may be indicative of the expansion of extracellular volume and the deposition of excessive collagen. • The relationship between diastolic dysfunction and diffuse myocardial fibrosis may be demonstrated by imaging markers. • Non-contrast T1ρ mapping may have the potential to be used for diffuse myocardial assessment.