MR lymphangiography for the assessment of the lymphatic system in patients undergoing microsurgical reconstructions of lymphatic vessels

Abstract

Objective To assess the morphology of the lymphatic system pre- and postoperatively in patients undergoing microsurgical reconstructions of the lymphatic vessels. Materials and methods 8 lower extremities in 4 consecutive patients with secondary unilateral lymphedema of the lower extremities were examined by MR lymphangiography. 18 mL of gadoteridol and 1 mL of mepivacainhydrochloride 1% were subdivided into 10 portions and injected intracutaneously into the dorsal aspect of each foot at the region of the four interdigital webs and medial to the first proximal phalanx. MR imaging was performed with a 1.5-T system equipped with high-performance gradients. For MR lymphangiography a 3D-spoiled gradient-echo sequence was used. For evaluation of the lymphedema a heavily T2-weighted 3D-TSE sequence was performed. Results In 2 patients the 3D-TSE sequence demonstrated a decrease of the epifascial lymphedema in the postoperative acquisitions, whereby MR lymphangiography displayed an improvement of dermal-back areas and collateral lymphatic vessels. In one patient the epifascial lymphedema of the lower extremity decreased, whereas the diameter of the lymphatic vessels showed a constant diameter of 2 mm. In one patient with a lymphocutaneous fistula at the level of the right groin, the feeding lymphatic vessels and contrast media extravasation could clearly be visualized. The 3D-TSE sequence demonstrated an epi- as well as subfascial lymphedema of the right leg. Conclusion MR lymphangiography is a safe and accurate diagnostic imaging method for the pre- and postoperative evaluation of the lymphatic circulation in patients undergoing microlymphatic surgery. Due to the minimal-invasiveness and lack of radiation, diagnostic follow-up MR lymphangiography examinations can be performed routinely and with no risk for the patient.