The ultrasonic estimation of fetal weight at delivery is of important prognostic significance in obstetrical practice. The convertional regression formulas used for estimating fetal weight have the disadvantage of less reliability. In this study, we used the back propagation neural network (BP) to estimate Fetal Weight. Some input variables were adopted in constructing the BP model: biparietal diameter (BPD), cerebellum transverse diameter (TCD), abdominal circumference (AC), liver length (LL), femur length (FL), fetal thigh soft tissue thickness (FSTT), and gestational age (GA). The fetal weights of 109 singleton fetuses were estimated. In the training group and validation group, coincidence rates were 89.77% and 76.19% respectively. The results show that the estimation based on neural network is more accurate than that by regression method. GA, its unit is not week but day in our formulas, is very valuable in combination with other ultrasonic parameters on estimation.
Anthropometry ; methods ; Birth Weight ; Female ; Fetal Weight ; Gestational Age ; Humans ; Infant, Newborn ; Neural Networks (Computer) ; Pregnancy ; Regression Analysis ; Term Birth

Objective To investigate sonographic characteristics of struma ovarii with conventional ultrasound and CEUS.Methods Ultrasound images of 65 patients with struma ovarii confirmed by pathology were retrospectively reviewed and analyzed,5 patients were examined with CEUS simultaneously.Results In all 65 patients,lesions in 14 (14/65,21.54 ％) were multocular,49 (49/65,75.34％) were cystic-solid component,2 (2/65,3.08％) were solid.Lesions in 39 (39/65,60.00％) contained dense latticed separation.The abundant blood flow was found in 18 cases (18/65,27.69％) with Doppler examination.Five cases were examined with CEUS,including multilocular lesions of 2 cases and cystic-solid lesions of 3 cases.Regular middle-degree intensity of cyst wall and septa were seen in all 5 cases.Among cystic-solid lesions of 3 cases,lesions of non-enhance pattern was seen in the solid areas of 1 case,irregular middle-high degree intensity pattern were seen in the solid areas of 2 cases,while non-enhance pattern could be seen in part of the solid areas of these 2 cases.All the cystic areas of these 5 cases showed non-enhance pattern.Conclusion The sonographic appearances of struma ovarii are usually multilocular or multilocular with solid component.Because of strum ovarii's special characteristic pathologic components,the imaging features of strum ovarii in conventional ultrasound and CEUS are atypical,thus preoperative diagnosis is quite difficult.