Methods: Between November 2022 and May 2025, a total of 33 patients (22 males, 11 females; median age: 44 months; range, 37 to 57.5 months) with single-ventricle congenital heart disease who underwent T2-weighted magnetic resonance lymphangiography at our center were retrospectively analyzed. The T2-weighted sequences were chosen for their high-resolution depiction of lymphatic structures without the need for contrast agents. The imaging findings were analyzed for preoperative risk evaluation or suspected postoperative lymphatic complications.

Results: Lymphatic abnormalities were categorized into types 1 to 3 based on the extent and distribution of T2-hyperintense signals. No patients in this cohort exhibited type 4 abnormalities. Among 33 patients, 11 (33%) were classified as type 1, 18 (55%) as type 2, and four (12%) as type 3. Although not statistically significant, patients with type 3 patterns had the longest median pleural effusion duration (27.5 days) and length of hospital stay (61 days). One patient showed early postoperative progression from type 2 to type 3, which resolved clinically and radiologically after fenestration ballooning. In the late period, two patients developed protein-losing enteropathy, and one had Fontan failure.

Conclusion: Magnetic resonance lymphangiography provides critical information about structural lymphatic abnormalities. It also aids risk stratification prior to the Fontan procedure and guides individualized management of postoperative complications, ultimately guiding treatment and improving outcomes.