Study on the relation between subcutaneous tissue bioimpedance and ultrasonography in various leg edema. - Correlation between leg bioimpedance and subcutaneous ultrasonography findings.

We tried to test the correlation between the severity of subcutaneous echo-free space (SEFS) observed by ultrasonography and the ratio of intracellular fluid resistance to extracellular fluid resistance (Ri/Re), a surrogate parameter of fluid status assessed by bioelectrical impedance spectroscopy (BIS), in the legs with edema. Seventy legs with venous edema (VE) and 68 legs with lymphedema (LE) were studied. In the lower calf, SEFS grade showed good linear correlation with Ri/Re of the whole leg regardless of type of edema (Lower medial calf, VE: SEFS 0; 3.2+/-1.4, 1; 4.0+/-2.2, 2; 4.9+/-4.0, LE: SEFS 0; 3.2+/-0.8, 1; 3.8+/-1.7, 2; 5.3+/-3.4) . However, such correlation was not obtained in the other parts of the leg. Thus we found that severity of SEFS in the lower calf well represents the fluid status of the whole leg.