In Vivo Quantification of Relaxation Times of Abdominal Tissues at 5.0 T MRI: A Preliminary Study in Healthy Volunteers.

OBJECTIVES

To establish normative T1 and T2 relaxation times for the liver, pancreas, and kidneys at 5.0 T MRI, providing reference data for imaging parameter optimization and quantitative diagnosis.

MATERIALS AND

METHODS

Standardized T1/T2 phantoms were used for in vitro validation. From January to March 2025, healthy adults underwent 5.0 T abdominal MRI. T1/T2 maps were obtained using Modified Look-Locker Inversion Recovery (MOLLI) and T2-prepared gradient echo (T2 prep) sequences. Values, reproducibility, and correlations with age, sex, and other factors were evaluated.

RESULTS

Results from the 10 tubes showed excellent agreement with MOLLI-based T1 and T2-prep-based T2 values and reference standards. The final cohort consisted of 41 participants. In healthy volunteers at 5.0 T MRI, mean T1 values were 1131.68±123.03ms(liver), 1164.63±57.81ms(pancreas), 1753.62±80.44ms (kidney cortex), and 2175.06±100.80ms (kidney medulla); mean T2 values were 31.16±3.37ms, 47.48±4.55ms, 59.36±6.35ms, and 41±4.07ms, respectively. T1 and T2 showed excellent reproducibility. Correlation analysis demonstrated a significant linear negative correlation between R2* and liver T1, and the R2* corrected liver T1 was 1156.57±69.25ms. Liver T2 decreased with age, and both measured and corrected liver T1 decreased with waist-to-hip ratio. Measured T1 and T2 of liver and kidney (cortex and medulla) were all lower in males than females, but liver corrected T1 showed no sex difference.

CONCLUSION

This study reports normative T1 and T2 relaxation times of the liver, pancreas, renal cortex, and medulla at 5.0 T MRI, confirming the method's feasibility and reproducibility, thus providing reference values for parameter optimization and future disease-related research.

KEY POINTS: Question Quantitative 5.0 T MRI is diagnostically significant, but normative reference values for abdominal T1/T2 relaxation times are currently lacking. Findings We established normative T1/T2 values for abdominal organs at 5.0 T MRI, providing a reference for protocol optimization and diagnosis. Clinical relevance This study establishes normative T1 and T2 relaxation times for abdominal organs at 5.0 T MRI. These reproducible, quantitative reference values are essential for optimizing imaging protocols and provide a robust baseline for diagnosing abdominal diseases.