Thoracic duct and cisterna chyli: evaluation with multidetector row CT.

ABSTRACT

OBJECTIVES: The aim of this study was to evaluate the normal anatomy of the thoracic duct and cisterna chyli obtained by axial and multiplanar reformation (MPR) images of 1 mm slice thickness using multidetector row CT (MDCT). METHODS: We evaluated the ability of MDCT to examine the normal anatomy of the thoracic duct and cisterna chyli. The axial and coronal images of thoracoabdominal MDCT images obtained in 50 patients (20 females and 30 males; mean age, 63.5 years; range, 32-81 years) were reviewed between January and October 2005. We excluded patients with malignant neoplasms, inflammation or vascular diseases (e.g. aortic aneurysm, aortic dissection) and those with a history of thoracoabdominal surgery. The thoracic duct was divided into three anatomical sections the upper, middle and lower. We evaluated the degree of visualisation and the maximum size of the thoracic duct. We also evaluated the degree of visualisation, maximum size, configuration and location of the cisterna chyli. RESULTS: Visualisation of the thoracic duct and cisterna chyli was almost 100% on axial and coronal images. The lower section of the thoracic duct was most clearly visualised among the three sections. There was little difference in the maximum size of the thoracic duct among the three sections. The cisterna chyli was most frequently located at the Th12 or L1 level, and the most common type was the "straight thin tube type". CONCLUSION: Axial and MPR images of 1 mm slice thickness using MDCT can clearly depict the thoracic duct and cisterna chyli.