Magnetic resonance thoracic ductography assessment of serial changes in the thoracic duct after the intake of a fatty meal

Abstract

The thoracic duct, a terminal lymph vessel, is thought to dilate after the intake of a fatty meal. However, this physiological change has not been well explored in vivo. Therefore, the present study aimed to assess serial changes in the thoracic duct after the intake of a fatty meal using magnetic resonance thoracic ductography (MRTD). Eight healthy volunteers were subjected to one MRTD scan before a fatty meal and eight serial MRTD scans every hour thereafter. The cross‐sectional areas of the thoracic duct were estimated using MRTD measurements of the diameters of the thoracic duct at the upper edge of the aortic arch, the tracheal bifurcation, the mid‐point between the tracheal bifurcation and the left part of the diaphragm and the left part of the diaphragm. The change‐rates in these areas were calculated before and after the fatty meal intake, and the maximal change‐rate and timing of its achievement were determined for each subject. The summed change‐rates in the four portions of the thoracic duct ranged from −40.1 to 81.3%, with maximal change‐rates for each subject ranging from 22.8 to 81.3% (mean, 50.4%). Although individual variations were observed, most subjects (88.9%) exhibited a maximal change‐rate at 4–6 h after meal intake, with subsequent decreases at 7–8 h. In conclusion, MRTD revealed a tendency toward thoracic duct enlargement at 4–6 h after the intake of a fatty meal, followed by contraction.

Sonography for assessment of thoracic duct anatomy and physiology before and after meals

“…The TD dilated significantly after a meal. This phenomenon is well known and used in the TD imaging as well as in surgery (Chen et al, 2017; Nomura et al, 2018; Robinson, 1985). It is arguable if the dilation we have seen was caused by fat absorption.…”

Back to the Future II—A Comprehensive Update on the Rapidly Evolving Field of Lymphatic Imaging and Interventions

“…However, there are considerable individual variations making timing difficult. Although one investigation described a peak of thoracic duct enlargement approximately 3–4 hours 100 after ingestion of a high fat meal, 4–6 hours were described in a different cohort 101 . Because of the uncertainty of clinical use in a single patient and more complex logistics, the author does not routinely give high fat meals before noncontrast lymphangiography.…”

“…20 When performing noncontrast thoracic ductography, some authors have suggested improving image quality by a prior high fat meal. [100][101][102] Oral or enteral administration of, for example, cream increases flow in the thoracic duct, thereby potentially improving visibility on noncontrast MRL. However, there are considerable individual variations making timing difficult.…”