Application of two and three-dimensional ultrasound measurement of fetal thymus in fetal intrauterine growth restriction

Abstract

To measure the ultrasonic parameters of transverse diameter, anteroposterior diameter and volume of fetal thymus through two and three-dimensional (2D and 3D) probes, establish normal reference range of fetal thymus development and assess the correlation between fetal intrauterine growth restriction and fetal thymus development. A total of 53 patients with suspected fetal intrauterine growth restriction (IUGR) at our hospital from December 2012 to May 2014 were selected into the observation group while another 53 cases as the control group corresponding to the former group's gestational week (GA). The transverse and anteroposterior diameters were measured in the three vessel view by 2D-ultrasound and the volume of fetal thymus was measured through 3D ultrasound. The control parameters were analyzed by linear regression analysis. And two groups of parameters were tested by rank sum test. P < 0.05 was deemed significant. The regression equation of fetal thymus transverse diameter and GA was: Y = 0.14X-1.174, R² = 0.766, P < 0.05; the regression equation of fetal thymus anteroposterior diameter and GA was: Y = 0.49X-0.166, R² = 0.792, P < 0.05; the regression equation of fetal thymus volume and GA was: Y = 0.652X-10.611, R² = 0.791, P < 0.05. Two groups underwent rank sum test of fetal thymus transverse diameter, anteroposterior diameter and volume (P < 0.05). Fetal thymus transverse diameter, anteroposterior diameter and volume increase with gestational weeks. In IUGR, fetal thymus transverse diameter, anteroposterior diameter and volume are less than those of the same GA fetal thymus.