Radiology of the thoracic duct.

Abstract

The appearance of the thoracic duct was analyzed in 390 sequential lymphangiograms.The classic bulbous dilatation of the cisterna chyli was visualized in 53 per cent of cases. It was located at the T-12 to L-2 levels and was usually less than 5 cm. in length.The thoracic duct varied in size from 1 to 7 mm. Valves were visible in 84 per cent of cases (usually in the upper third of the duct). Double thoracic ducts, bilateral superior mediastinal ducts, and multiple variations in the cervical segment of the duct were observed. Intercostal lymphatic vessels were occasionally filled in normal studies. In the presence of mediastinal masses, the distance between the lateral tracheal wall and the thoracic duct measured greater than the normal of 10 mm. Kinking, tortuosity, and displacement of the duct were also apparent.Thoracic duct obstruction may be diagnosed by a sharp cut-off in its course, dilatation, tortuosity, visualization of collateral channels, and delayed emptying. If the site of obstruction is not c...