LOCAL TISSUE WATER CHANGES ASSESSED BY TISSUE DIELECTRIC CONSTANT: SINGLE MEASUREMENTS VERSUS AVERAGING OF MULTIPLE MEASUREMENTS

Abstract

Previous reports describe the use ofaverage tissue dielectric constant (TDC)measurements to assess local tissue water andits change. Our goal was to determine if asingle TDC measurement could be used inplace of the average of multiple measurements.The comparison criteria used to test this wasthe extent to which single and averagedmeasurements yielded similar TDC values inboth normal and lymphedematous tissue.Measurements were made on both ventralforearms to a depth of 2.5 mm in 10 womenwith unilateral arm lymphedema. The mainresults showed that the 95% confidenceinterval for differences between single andaveraged TDC values was less than ±1 TDCunit for both normal and lymphedematousarms. This finding strongly suggests that formost, if not all, clinical evaluations, suitableassessments can be made using a single TDCmeasurement.