Novel Lymphatic Imaging Techniques.

The lymphatic system plays an important role in immune regulation, transport of metabolites, and fluid balance. The key circulatory role of the lymphatic system is to transport fluid from tissue back into the venous system via lymphovenous connections. Despite the centuries-old recognition of this key role, there has been poor understanding of lymphatic flow pathophysiology because of a lack of a simple reliable noninvasive clinical lymphatic imaging method. This lack of clinical imaging has limited the treatment options for patients with lymphatic flow disorders. Recent development of noncontrast magnetic resonance (MR) lymphangiogram and dynamic contrast MR lymphangiography make it possible to visualize central lymphatic anatomy and flow dynamics with high spatial and temporal resolution. Dynamic contrast MR lymphangiography has provided insight into understanding the pathophysiology of several pulmonary lymphatic flow disorders and provides guidance for interventional procedures. Another important development has been intranodal lymphangiogram, which has now replaced pedal lymphangiogram as the main lymphatic interventional modality, and which provides quick and reliable access to the central lymphatic ducts for interventional procedures. These new techniques have led to a resurgence in interest in the lymphatic system and the development of new treatments for patients with lymphatic flow disorders.