Comparison of characteristic CT findings of lymphedema, cellulitis, and generalized edema in lower leg swelling.

To determine the different computed tomography (CT) findings of lymphedema, cellulitis, and generalized edema in the lower leg. CT images of 44 patients with confirmed lymphedema (n = 19), cellulitis (n = 11), or generalized edema (n = 14) were retrospectively reviewed. The following characteristics were evaluated: extent of edema, laterality, skin thickening, honeycombing, taller than wide appearance, muscle edema, conglomeration of septum of fat lobule, fluid collection, fascial enhancement, inguinal lymph node (LN) enlargement, medullary fat obliteration of inguinal LN, trunk subcutaneous edema, and bone marrow edema. Fisher's exact test with Bonferroni correction was used for multiple comparisons. Honeycombing and taller than wide appearance of fat lobules were more common in lymphedema (P < 0.01). Fat obliteration of inguinal LN and inguinal LN enlargement at the affected side were more common in cellulitis (P < 0.01). Bone marrow and subcutaneous edema of the trunk were more common in generalized edema (P < 0.01). Honeycombing is commonly seen in lymphedema, but is not a specific finding. Inguinal LN enlargement is a specific sign of cellulitis. Truncal edema and bone marrow edema were specific findings of generalized edema.