THE REAL LIMITS OF ACCURACY OF MEASUREMENTS OF VARIOUS STRUCTURES USING MODERN ULTRASOUND DIAGNOSTIC EQUIPMENT

Abstract

Aim. The purpose of the study is to establish real measurement accuracy for various structures during the biometrics on modern ultrasound equipment. Organization and Methods. Three series of measurements were conducted. The first one was done on a perfect static sonogram with an object of known value. The second series was the measurement of ideal objects of known value on the precision ultrasonic phantom. The third series involved measurement of a real object – fetal femur length. The data obtained in the course of the study was processed in Microsoft Excel 2007 with functions VAR, AVERAGE, NORMDIST, and others. Results. The following results were obtained: for the measurements on the ideal static objects the error was 0.1 mm; for the measurements of static objects on the precision ultrasonic phantom the error was 0.2 mm; for the measurements of the real object – the fetal femur length was 0.5 mm in the 2nd trimester and 1.0 mm in the 3rd trimester of pregnancy. Conclusion. The real error in the measurements of structures performed on ultrasonic diagnostic devices cannot be less than 0.2–0.5 mm. It is necessary to be cautious while applying of various algorithms for interpretation of biometrics results, in which the difference in values of 0.1 mm can significantly influence the tactics of pregnancy assessment and observation, for example – the algorithm for calculating risks of FMF fetal chromosomal abnormalities.