Morphological changes of the thoracic duct and accessory lymphatic channels in patients with chylothorax: detection with unenhanced magnetic resonance imaging.

OBJECTIVES: To characterise the imaging findings of patients with chylothorax and to identify the leak site using unenhanced MRI.
METHODS: Seven patients with chylothorax and 30 healthy individuals (as the control group) underwent three-dimensional heavily and routine T2-weighted MRI. Morphological changes and diameters of the thoracic duct, chyloma display, and some dilated accessory lymph channels were evaluated and measured. The differences between patients and the control group were compared. The leak sites of the thoracic duct and parietal pleura were also identified.
RESULTS: The patients had a higher display rate of the entire thoracic duct and some accessory lymphatic channels, enlarged diameters and tortuous configuration of the thoracic duct, and existence of chylomas compared with the control group (P < 0.05). Seven leaks of the thoracic duct in five patients and five leaks of the parietal pleura in four patients were identified. Close relationships between the leak of thoracic duct and the chylomas or the meshworks of tiny lymphatics were found (P < 0.05).
CONCLUSION: Unenhanced MRI appears reliable in the detection of morphological changes of thoracic lymphatics and in the identification of chyloma and leak sites in patients with chylothorax, which helps appropriate treatment planning and follow-up.