Objective To evaluate the value of three-dimensional ultrasound volume contrast imaging (VCI) and tomo graphy ultrasound imaging (TUI) techniques in observing fetal spinal conus medullaris (CM) position and lumbar enlargement of spinal cord morphologic changes,for assessment of tethered cord (TC).Methods Totally 17 abnormal fetuses of spinal diseases combined with TC (abnormal group) were examined by three dimensional ultrasound VCI and TUI techniques.The position of CM was recorded,and the transverse and anteroposterior diameters of lumbar enlargement of spinal cord were measured and compared with 300 cases of normal fetuses (normal group).Results As the growth of the gestational age (CA),CM terminal position increased.All the ends of CM located at L3 or L3 above level in normal.The transverse and anteroposterior diameters of lumbar enlargement in normal group showed good linear relationship with GA.Transverse diameter (mm) =0.677+0.147 ×GA (R2 =0.836,P＜0.05),anteroposterior diameter (mm)-0.994+ 0.152× GA (R2=0.894,P＜0.05).Compared with the corresponding GA fetuses in normal group,the anteroposterior diameter of lumbar enlargement decreased in abnormal group (P=0.002),while no statistical difference of the transverse diameter was found between the two groups (P=0.082).Conclusion Position of CM and lumbar enlargement measure ment can provide valuable reference information for clinical prenatal diagnosis of fetal spinal TC.

Objective To investigate the value of prenatal ultrasound in diagnosis of fetal posterior urethral valve (PUV) and the differential diagnosis of related diseases.Methods The antenatal ultrasonographic manifestations and the outcomes of 14 cases with congenital lower urinary tract obstruction (LUTO) in Shengjing Hospital of China Medical University from December 2014 to December 2016 were analyzed.The ultrasound features and differential diagnosis of fetal posterior urethral valve were summarized and analyzed.Results Fourteen male fetuses with LUTO were prenatally diagnosed.Eleven fetuses were diagnosed as PUV,I as urethral atresia,2 as megacystis and LUTO.Among the fourteen fetuses,11 were confirmed as PUV after delivery,1 as urethral atresia,2 as vesicoureteral reflux (VUR).One case among them was diagnosed as PUV,and latter proved to be VUR.In 2 cases among them,prenatal ultrasound indicated megacystis,but 1 case was proved to be PUV,and 1 case was VUR.The prenatal ultrasound of the PUV fetuses showed enlarged bladder and thickened bladder wall.Most of them were accompanied by the keyhole sign.Conclusion Prenatal ultrasound can assist in the diagnosis of PUV by analyzing the anatomy of the bladder and accompanying malformations,which provides valuable diagnostic information for the clinical practice.

Objective To evaluate the repeatability for location of the level of fetal conus medullaris (CM) with three-dimensional volume contrast imaging (3D-VCI).Methods Totally 164 normal fetuses and 12 fetuses with low-lying CM were enrolled.The location of fetal CM was performed sonographically using 3D-VCI,and the inter-and intra-observer agreement was assessed.Results The Kappa value of inter-and intra-observer agreement in evaluation on normal fetues CM was 0.943 and 0.915,and that for abnormal fetues CM was 0.965 and 0.913,respectively.Conclusion Inter-and intra-observer agreement of 3I-VCI in location of level of fetal CM is high.The acquired images are clear and intuitive,which is manipulated simply and conveniently.This method can be used for rapid evaluation of the level of fetal CM.

Purpose To discuss the ultrasonic cardiogram of cardiac rhabdomyoma,and to analyze the change trend of single and multiple rhabdomyoma before and 6 months after childbirth.Materials and Methods Eleven fetuses diagnosed as cardiac rhabdomyoma prenatally from January 2014 to January 2016 were analyzed retrospectively,and the tumor size,number and anatomical location were recorded by ultrasound.The 11 fetuses were divided into single group and multiple group,and both groups were reviewed the changes to tumors during pregnancy and within postnatal 6 months.Results For 11 cases with rhabdomyoma,6 cases were in the multiple group,with tumors growing in 5 cases,and tumors unchanged in 1 case,and 5 cases were in the single group,with all tumors unchanged.The prenatal difference between the two groups was statistically significant (P＜0.05).After six months follow-up of 11 fetuses with cardiac rhabdomyoma,tumor regression occurred in 2 cases of the multiple group,tumors were unchanged in 4 cases,tumor regression occurred in 2 cases of the single group,tumors were unchanged in 3 cases,and there was no significant difference between the fetuses in the two groups within postnatal 6 months (P＞0.05).Conclusion The cardic rhabdomyoma has a tendency to increase in the prenatal period,and the increase may be significant in the multiple group.The rhabdomyoma is relatively stable within 6 months follow-up after birth,and there is a partial regression trend,without significant difference between single and multiple groups.

Objective To study the ultrasonographic features and differential diagnosis of fetal penoscrotal transposition.Two dimensional and three dimensional ultrasound were applied in the diagnosis of fetal penoscrotal transpositionto improve the detection rate. Methods Twenty cases of suspected penile scrotal transposition of the fetus in Shengjing Hospital affiliated to China Medical University fromJanuary 2015 to February 2017were included in present study. The ultrasound findings, fetal chromosome examination and clinical follow-up outcome were retrospectively summarized. Results Among the 20 suspected cases of penile scrotal transposition, 17 cases were diagnosed correctly. All the 17 cases were partial type of penile scrotal transposition. In the remaining 3 cases, 2 caseswere hermaphroditism with the karyotype of 46-XX, and the other 1 case was confirmed as normal female fetusesby clinical follow-up after birth. The ″tulip″signwas the typical ultrasonographic features offetal penoscrotal transposition. Conclusion 2D combined with 3D ultraosound is useful in diagnosis and differential diagnosis of fetal penile scrotal transposition.

Objective To investigate the sonographic characteristics of prune belly syndrome (PBS) in early period of second trimester. Methods A total of 16 pregnancies with diagnosis of PBS were enrolled between January 2014 and March 2017. Their sonographic characteristics and autopsy outcomes were analyzed. Results Overdistension of fetal bladder and flimsy fetal abdominal wall were found in all 16 cases. And there were 5 cases found prenatally to be associated with other abnormalities, including single umbilical artery (2 cases), sacrococcygeal teratoma (1 case), spina bifida manifesta (1 case) and strephenopodia (1 case). All women decided to terminatethe pregnancy, and deficiency of the abdominal musculature and increased collagen fiber were found by autopsy. Because of the confusion of the huge bladder, one case associated with imperforate anus was missed by prenatal ultrasonography. Conclusion Prenatal diagnosis of PBS in early period of second trimester is very important, because the amniotic fluid volume is still enough to evaluate the fetal structure.

Objective To assess the application value of real time three-dimensional (RT-3D) ultrasonography in diagnosis of fetal corrected transposition of the great arties (cTGA). Methods Data of 14 fetuses diagnosed as cTGA clinically were reviewed. With 2D ultrasonography, diagnosis views were obtained and then studied using cardiac three-section analytic method. With real time 3D (RT-3D) ultrasonography, volume datasets were acquired at the level of four chamber view, and spatio-temporal image correlation (STIC) was then used to analyze the relationship of the two great arties. Confirmed by infant echocardiography and the autopsy findings, the accuracy of RT-3D and 2D ultrasonography in evaluation of fetal cTGA and complications were compared. Results The accuracy rate of RT-3D and 2D ultrasonography in diagnosis of fetal cTGA was 92.86% and 71.43% (χ~2=2.19, P=0.14). The procedure time of RT-3D ultrasonography was significantly shorter than that of 2D ultrasonography (t=10.23, P＜0.001). Conclusion RT-3D ultrasonography can evaluate fetal cTGA and its complications more quickly and exactly than conventional 2D ultrasonography.

Pulmonary hypoplasia (PH) may lead to severe respiratory distress immediately after birth,even neonatal death. The etiological factors, clinical, ultrasonic and pathologic characteristics of PH and the proposed methods for the prenatal diagnosis were reviewed in this article.

Objective To assess the application of automated four-dimensional (4D) volume color Doppler ultrasonography in normal fetal heart screening. Methods Four-dimensional volume color Doppler was acquired at the level of four chamber view level in 120 fetuses from 18 to 23 weeks of gestation. Three diagnostic planes including color Doppler information were retrieved by automated multiplanar imaging from the 4D volumes. The left ventricular outflow view (cardiac plane 1), the right ventricular outflow view (cardiac plane 2) and ductal arch view (cardiac plane 3) were acquired. Tomographic ultrasound imaging (TUI) was added to display all the three diagnostic planes. The data were then analyzed to determine whether cardiac planes 1-3 were displayed correctly in each volume. Results Automated 4D volume color Doppler ultrasonography displaying rate of cardiac plane 1, cardiac plane 2, cardiac plane 3 were 100%, 96.67% and 91.67%, respectively. Cardiac plane 1 was displayed at least three TUI plane, cardiac plane 2 was displayed at least two TUI plane, and cardiac plane 3 was displayed at least two TUI plane. Conclusion It is possible to acquire important planes of the fetal heart with automated 4D volume color Doppler ultrasonography and the visualization rate of the three diagnostic planes is fine.

Objective To discuss the method and skill of prenatal diagnosis of fetal isolated pulmonary stenosis and thus to improve prenatal diagnostic ability. Methods The data of 18 fetuses diagnosed as isolated pulmonary stenois were reviewed and the ultrasonic characters of each section were analysised. Results Five of the 18 cases were confirmed as pulmonary stenosis by autopsy and 12 cases were confirmed by echocardiography after birth. One case was confirmed as pulmonary atresia by echocardiography after birth. Reversed blood flow in arterial duct was detected at the ductal arch section in all the cases and right atrial enlargement,right ventricular myocardial hypertrophy, tricuspid regurgitation, foramen ovale enlargement, reduced activity of foramen ovale valve were detected in partial cases. Conclusions It is important that reversed blood flow in arterial duct and in the two main artery could be observed at the ductal arch section and the three vessel section respectively. Ductal arch section,ventricular outflow tracts section and the three vessel section are very important in the diagnosis of fetal isolated pulmonary stenosis.