CIO 2021-31 Intranodal CT Lymphangiography Using Water-Soluble Iodinated Contrast for the Imaging of the Central Lymphatic System

Purpose: To evaluate the feasibility of intranodal CT lymphangiography (ICTL) imaging for diagnosis and planning of subsequent intervention in patients with thoracic lymphatic disorders.

Material and Methods: In this retrospective review, five women with suspected lymphatic abnormalities ranging from traumatic chylothorax to plastic bronchitis, and contraindications to MRI, underwent ICTL from September 2019 to May 2020. 25G needles were placed in the bilateral inguinal lymph nodes under US guidance, and water-soluble iodinated contrast was injected. CT fluoroscopy was used to monitor the opacification of the cisterna chyli to determine the timing of the CT scan. After ICTL, the thoracic duct (TD) was catheterized, and lymphangiography through the thoracic duct catheter was performed. Imaging findings of ICTL and the subsequent lymphangiography were then visually compared by utilizing 3 dimensional reconstructions.

Results: Intranodal injection of water-soluble contrast was successful in all patients evaluated (5 women; mean age: 68y ± 11 [range, 53-83]). The central lymphatics were opacified in 4 of the 5 women, demonstrating abnormal pulmonary lymphatic flow from the thoracic duct into the lung parenchyma. In 1 of the 5 women, the thoracic duct injection showed successful ligation of the thoracic duct. The time elapsed from contrast injection to visualization of the thoracic duct ranged from 2-27 minutes. ICTL and the lymphangiography findings matched well.

Conclusions: Intranodal CT Lymphangiography sufficiently delineated central lymphatic anatomy in patients with lymphatic abnormalities, thereby demonstrating its use as a feasible alternative to more technically challenging methods such as dynamic contrast-enhanced MR lymphangiography.