ABSTRACT
Objective To assess the feasibility of real-time Bi-Plane in observing normal mitral annular areas in different gestational ages.Methods Routine two-dimensional echocardiography and real-time Bi-Plane were used to observe mitral structure and measure the mitral annular area in 159 fetuses.Pearson correlation analysis was used to evaluate the correlation of the areas with gestational age.Visualization rates and acquisition time were recorded and analyzed statistically.Resuits The mitral annular areas measured by two techniques were both correlated to the gestational age (r=0.71,0.75,both P＜0.05).There were significant differences in visualization rate (x2 =4.375,P=0.036) of mitral annular area and acquisition time (t=6.11,P＜0.05) between routine two-dimensional echocardiography and real-time Bi-Plane.Conclusion Real-time Bi-Plane technique is direct,accurate,convenient and fast in observing mitral prenatally.By using Bi-Plane technique to measure mitral annular area,abnormal morphology changes of mitral valve can be evaluated,so as to provide great application value for clinic.
ABSTRACT
Objective To retrospectively assess the diagnostic value of nuchal translucency (NT) thickness and facial profile ultrasonic markers [including frontomaxillary facial (FMF) angle,and the ratio of prenasal thickness to nasal bone length (PT/NBL)] for trisomy 21 syndrome in first-trimester fetuses.Methods Ultrasonograhic images of 35 fetuses with trisomy 21 syndrome and 70 gestational age matched normal fetuses were analyzed in first-trimester.NT,FMF angle and the PT/NBL ratio were measured retrospectively in stored images from digital database between January 2012 and December 2015.The diagnostic value of NT,FMF angle and PT/NBL ratio were compared with different combinations.Results (1) The mean NT was significantly higher in the trisomy 21 group than that in controls (t =7.401,P =0.00).The NT above 2.5mm was observed in 20 trisomy 21 fetuses (57.1％) and in 3 normal fetuses (4.3％).(2) The mean FMF angle was significantly higher in the trisomy 21 group than that in controls (t =-5.283,P =0.00).The FMF angle above the 95th percentile (93.6°) was observed in 13 trisomy 21 fetuses (37.1％) and in 1 normal fetus (1.4％).(3) The mean PT/NBL ratio was significantly higher in the trisomy 21 group than that in controls (t =-7.826,P =0.00).The PT/NBL ratio above the 95th percentile (0.93) was observed in 19 trisomy 21 fetuses (54.3％) and in 4 normal fetuses (5.7％).(4) The sensitivity and Youden index for trisomy 21 increased gradually,which were 57.1 ％ and 0.528 by using NT,and 74.3％ and 0.686 by using NT and FMF angle,and 91.4％ and 0.828 by using NT,FMF angle and PT/NBL ratio.There were significant differences in the detection rates of trisomy 21 among the three strategies,while the diagnostic specificity of the three strategies were more than 90％.Conclusions The three parameters are significantly increased in trisomy 21 fetus in first-trimester.First,increased NT was most commonly detected,followed by increased PT/NBL ratio,and increased FMF angle again.Detection rates for trisomy 21 fetuses in first-trimester by ultrasound screening can be significantly improved if combination of all three parameters rather than just one parameter are performed.