Characterization of Central Lymphatic Anatomy and Flow in Healthy Volunteers Using Dynamic Contrast-Enhanced MR Lymphangiography

Objectives To characterize central lymphatic anatomy and physiological flow dynamics in healthy volunteers using dynamic contrast-enhanced MR lymphangiography (DCMRL), thereby providing preliminary DCMRL-specific quantitative characterization of central lymphatic anatomy and flow dynamics. Materials and Methods In this prospective single-center study, healthy adult volunteers underwent DCMRL between April 2023 and March 2024. Thoracic duct (TD) morphology, outlet anatomy, length, width, and tortuosity were assessed on contrast-enhanced T1-weighted imaging, with additional width measurements on T2-weighted imaging. Quantitative flow analysis was performed using time-resolved contrast-enhanced sequences. Descriptive statistics, paired and independent t-tests, and Spearman correlation coefficients were applied. Results Sixteen participants (6 male, 10 female; median age 27 years, range 19-44) were included. The thoracic duct (TD) was visualized in all on T2-weighted imaging and in 14 on contrast-enhanced T1-weighted imaging. The cisterna chyli was visible in 13, and the TD outlet was left-sided in 15, with bilateral outlets in one. Fourteen TDs were tubular, with partial duplication in 2. On contrast-enhanced T1-weighted imaging (n=14), mean TD width was 4.43 ± 0.76 mm. On T2-weighted imaging, the corresponding mean TD width was 4.13 ± 0.25 mm. The mean TD length was 232 ± 20 mm, with a tortuosity index of 1.04 ± 0.02. Quantitative flow analysis in 13 participants revealed a steady flow pattern with a mean flow rate of 0.63 ± 0.41 mL/min. Conclusion This prospective study characterizes central lymphatic anatomy and flow physiology in healthy volunteers using DCMRL, highlighting modest physiological variability and a gradual increase in lymphatic contrast propagation, providing preliminary interpretive context for DCMRL interpretation.