Sonographic detection of physiological lower leg oedema in the late afternoon in healthy young women.

Lower leg oedema occurs physiologically in the evening after daytime activity. Various oedema-related sonographic findings have recently been reported, but this physiological oedema has not been evaluated quantitatively using imaging examinations. The present study investigated whether sonography could detect physiological lower leg oedema, comparing measured values between the morning and late afternoon. Diameters of leg veins were also measured as a possible source of leg oedema. Subjects comprised 55 healthy young women (mean age, 21 ± 1 years). Oedema-related findings such as papillary dermis thickness, subcutaneous adipose tissue thickness and echogenicity (as estimated in grey-scale using image analysis software) increased in the late afternoon when compared with those in the morning (1.4 [1.1-1.7] mm vs. 1.4 [1.1-1.8] mm, p < .01; 7.3 [6.0-8.1] mm vs. 7.3 [6.1-8.3] mm, p < .05; and 37.3 [31.5-39.4] vs. 39.8 [35.7-44.1], p < .01, respectively). Diameters of leg veins such as the great saphenous vein, small saphenous vein and dorsal vein of the foot were all reduced towards late afternoon (p < .01 each). Sonography quantitatively and precisely detected physical changes associated with physiological lower leg oedema after daytime activity in healthy young women.