To characterize lymphatic vessel morphology in lower extremity lymphedema using MR lymphography at 3T.

Forty females with lower extremity lymphedema secondary to gynecologic carcinoma treatment underwent MR lymphography (MRL) at 3T. Lymphatic vessel morphology in normal and affected limbs was compared.

The median diameter of the lymphatic vessels in swollen calf and thigh were significantly larger than that in the contralateral calf and thigh, respectively (p<0.05). The median number of lymphatic vessels visualized in normal calf was less than that in the lymphedematous calf (p<0.01), while no significant difference was found between the normal thigh and swollen thigh. Lymphatic vessel number in the affected calf was significantly greater than that in affected thigh and the mean diameter of affected calf was also significantly wider than that of affected thigh (p<0.01). Mean diameter of lymphatic vessels in the affected calf was significantly different between stage I and stage III (p<0.05), but not significantly different between stages I and II, and between stages II and III (p>0.05). The median number of lymphatic vessels for affected calf showed significant difference between stage I and stage III, and between stage II and stage III (p<0.05), but no significant difference between stage I and stage II (p>0.05). There was no significant difference in mean diameter or median number of lymphatic vessels in the affected thigh found between different stages (p>0.05).

There are significant differences in the number or diameter of lymphatic vessels between normal and affected limbs and there are significant differences for affected calf between early and late stages of lymphedema; therefore, MR lymphography can be helpful in diagnosis or clinical staging for lower extremity with gynecologic oncology-related lymphedema.