Three-dimensional isotropic fast spin-echo MR lymphangiography of T1-weighted and intermediate-weighted pulse sequences in patients with lymphoedema

• MR lymphangiography (MRL) proved to be a safe and effective method for assessing lymphatic drainage and lymphatic vessels.
• MRL could be helpful in preoperative planning for lymph vessel transplantation and lymphatic anastomosis.
• To date, MRL studies have focused on the 3D fast spoiled gradient-echo T1-weighted images.
• We demonstrate the feasibility of MRL using the 3D isotropic FSE pulse sequence with parallel imaging.
• 3D isotropic T1-weighted FSE MRL could provide useful information as to lymphatic vessels and drainage pattern of lymphatics.

AimTo evaluate the feasibility of magnetic resonance (MR) lymphangiography acquired using three-dimensional (3D) isotropic T1-weighted fast spin-echo (FSE) and 3D isotropic intermediate-weighted FSE sequences, as the new method of MR lymphangiography, and to compare the results of these two methods in patients with lymphoedema.Materials and methodsThirty-three extremities of 27 patients with primary or secondary lymphoedema and who had undergone radionuclide lymphoscintigraphy and MR lymphangiography with 3D isotropic T1-weighted FSE and 3D isotropic intermediate-weighted FSE were included in the study. The results of both imaging techniques were independently reviewed by two readers in consensus who rated the lymphatic drainage pattern, the quality of the depiction of lymphatic vessels and lymph nodes, and the level of lymph vessel enhancement. The assessment scores of each imaging sequence were compared using the Wilcoxon signed-rank test. The results were expressed as means with standard deviations.ResultsMore lymphatic vessels were visualised on T1-weighted FSE than on intermediate-weighted FSE (p<0.001). As more lymphatic vessels were detected on T1-weighted FSE, the per-extremity grade of the lymphatic drainage pattern was higher (p=0.046) and the visible levels of lymph-vessel enhancement were also significantly higher (p=0.004) on the T1-weighted FSE sequence, whereas the conspicuity of lymph nodes was superior on intermediate-weighted FSE (p=0.004).ConclusionMR lymphangiography using the 3D FSE pulse sequence is a feasible and noticeable new technique of MR lymphangiography. Between the two applicable protocols used, T1-weighted FSE provided better information regarding lymphatic vessels and their drainage, whereas intermediate-weighted FSE has the advantage of depicting lymph nodes in lymphoedematous extremities.