Lymphatic Imaging Techniques: Evaluation of the Central Lymphatic System

The central lymphatic system plays a pivotal role in fluid homeostasis, immune regulation and macromolecular transport. In children, lymphatic flow disorders are increasingly recognized as contributors to a wide spectrum of clinical conditions, particularly in those with congenital heart disease or postsurgical single ventricle physiology. Conditions such as chylothorax, plastic bronchitis, protein-losing enteropathy and generalized lymphatic anomaly often require detailed imaging for diagnosis and therapeutic planning. Advances in cross-sectional imaging have transformed the evaluation of pediatric lymphatic disorders. Traditional techniques like lymphoscintigraphy and conventional lymphangiography offer limited anatomical detail and functional insight. In contrast, noninvasive modalities such as noncontrast MR lymphangiography, contrast-enhanced ultrasound, CT lymphangiography and dynamic contrast-enhanced MR lymphangiography now enable high-resolution visualization of central conducting lymphatics, including the thoracic duct and cisterna chyli. This review describes the current techniques used to image the central lymphatic system in children, with a focus on dynamic contrast-enhanced MR lymphangiography, which has emerged as the reference standard for both anatomical mapping and functional assessment. We review clinical indications, access techniques, protocol optimization, interpretation frameworks and technical pitfalls to facilitate broader adoption and reproducibility of these techniques.