Renal cortical T1 times at 1.5 T: exploratory reference estimates from a real-world cohort with preserved renal function

Background Early detection of renal tissue alterations remains challenging, as laboratory markers often remain within the normal range until advanced stages of disease. T1 mapping offers a non-invasive approach to assess tissue composition, but data on typical renal cortical T1 times in real-world clinical populations at 1.5 T are limited. Aim To define exploratory real-world reference estimates for renal cortical T1 times and to assess their association with demographic and laboratory parameters in individuals with preserved renal function. Methods This retrospective study included patients undergoing clinical cardiac magnetic resonance (CMR) at 1.5 T in whom the kidneys were visible on native short-axis T1 maps. T1 times were derived from three manually placed regions of interest in the upper, middle, and lower renal cortex and averaged. Associations with sex, age, hemoglobin, and hematocrit were analysed. Results In a cohort without relevant comorbidities (n = 65), mean renal cortical T1 times were 1054 ± 53 ms (95% CI 1040–1067). Renal cortical T1 times showed no significant difference between women and men (1068 ± 34 ms vs. 1046 ± 60 ms, p = 0.21). No significant differences were observed across age groups (p = 0.34). Renal cortical T1 times were not significantly associated with hemoglobin (r = –0.10, p = 0.45) or hematocrit (r = –0.08, p = 0.54). Conclusion Renal cortical T1 times derived from routine CMR appear relatively stable across age and sex in individuals with preserved renal function. Opportunistic renal T1 assessment from routine CMR may provide additional, non-invasive information on renal tissue characteristics without extending scan time.