Abdominal Confluence of Lymph Trunks: Detectability and Morphology on Heavily T2-Weighted Images

Abstract

Our aims were to evaluate the detectability, configuration, location, and dimensions of the cisterna chyli on heavily T2-weighted images obtained with a single-shot fast spin-echo technique and to determine whether the disorders that have the potential to affect the abdominal lymphatic drainage could change the cisternal dimensions. Thin-collimated axial and coronal images that were originally obtained for MR cholangiopancreatography in 125 patients were reviewed by three observers individually for the presence of abdominal lymphatic confluence. The configuration, location, and dimensions of hyperintense ductal or saccular structures immediately anterior to the vertebral bodies below the diaphragma were recorded. The differences between the mean values of the diameters of the cisterna chyli obtained in the control group and in groups in which lymphatic drainage was expected to be abnormally high were compared using a one-way analysis of variance test. Abdominal confluence of the lymphatics was shown in 96% of patients. The most common configuration of the cisterna chyli was tubular (42.5%). It was located at the level of L1-2 in 33% of cases and at the midline in 70%. Mean longitudinal, anteroposterior, and transverse diameters of the duct were 33.45 +/- 1.74 (SD) mm, 5.23 +/- 0.13 mm, and 5.23 +/- 0.15 mm, respectively. No significant difference was found in the mean values of antero-posterior, transverse, and longitudinal diameters of the cisterna chyli in the control group and in the groups expected to have an increased flow into the cisterna chyli. Abdominal confluence of lymphatics seems to be present on most of the heavily T2-weighted images. Its morphologic details and extensions can be visualized on images reconstructed with a maximum-intensity-projection algorithm. Any disorder does not necessarily lead to dilatation of these lymphatic structures.