Clinical feasibility of noncontrast-enhanced magnetic resonance lymphography of the thoracic duct.

STUDY OBJECTIVE The dilatation of the thoracic duct was previously demonstrated in liver cirrhosis by lymphangiography, endoscopic ultrasound, and at autopsy. The evaluation of the morphologic change of the thoracic duct may be important in assessing the altered lymphodynamics in liver cirrhosis. The objectives of this study were to determine which combination of posture and breathing phase during noncontrast-enhanced magnetic resonance lymphography (MRL) provided the clearest images, and to evaluate the morphologic changes in the thoracic duct in healthy volunteers and patients with liver disease and malignancy. DESIGN Prospective study. SETTING Community general hospital. DESIGN AND SUBJECTS Twenty-three healthy volunteers and 113 patients underwent the MRL examination using a three-dimensional, half-Fourier, fast spin echo sequence on a 1.5-T, whole-body magnetic resonance system. The appropriate posture and breathing phase of MRL to obtain the best visualization was first determined by trial on 14 healthy volunteers. Morphologic changes of the thoracic ducts were evaluated in 23 healthy volunteers including the 14 healthy volunteers for the first trial and 113 patients using this appropriate method. The width of the thoracic ducts in both patients and volunteers was measured. MEASUREMENTS AND RESULTS MRL with respiratory gating in the supine position depicted the thoracic duct well and was the most comfortable for the subjects. In 82 of 113 patients (72.6%), the thoracic ducts were entirely visualized from the diaphragm level to the subclavian region. The remaining 31 patients had ducts that could not be entirely visualized due to sections or short lengths that were obscured. The maximum diameter was 3.74 +/- 0.81 mm in all healthy volunteers, 6.98 +/- 2.77 mm in alcoholic cirrhosis, 4.12 +/- 1.51 mm in nonalcoholic cirrhosis, 3.76 +/- 1.10 mm in malignancy, and 3.60 +/- 0.80 mm in chronic hepatitis (mean +/- SD). The diameter in alcoholic cirrhosis was significantly greater than in other groups (p < 0.01). CONCLUSIONS Respiratory gating in the supine position is the best MRL method for acquiring the clearest images. This may be a good method of detecting morphologic changes in the thoracic duct. The patients with alcoholic cirrhosis showed a greater thoracic duct diameter than other groups.