Purpose To investigate the diagnostic value of fetal echocardiography in total anomalous pulmonary venous connection (TAPVC),and to analyze the reasons ofmisdiagnosis so as to improve accuracy of prenatal diagnosis.Materials and Methods The prenatal echocardiographic data of 24 cases of TAPVC confirmed by postnatal echocardiography and prenatal MRI from October 2001 to December 2015 in Children's Hospital Affiliated to Nanjing Medical University and Shanghai Children's Medical Center Affiliated to Shanghai Jiaotong University School of Medicine were retrospectively analyzed.Results In 24 cases,there were 14 fetuses of supracardiac type,7 cases of intracardiac type,2 cases of infracardiac type,and 1 case of mixed type.15 fetuses had TAPVC only,whereas 9 cases were associated with other cardiovascular anomalies,most commonly including bilateral right atria,single atrium,single ventricle,common atrioventricular valve and pulmonary stenosis.On 4-chamber views,the common sonographic sign was absent of pulmonary venous return to the left atrium in 24 cases (100.0％),and the presence of venous confluence between left atrium and descending aorta was observed in 22 cases (91.7％).In all 24 cases,1 case was missed diagnosis,and 3 cases were misdiagnosed as persistent left superior vena cava,common pulmonary vein atresia and patent left atrial cardinal vein.Conclusion TAPVC can be accurately diagnosed by fetal echocardiography,but it is prone to be misdiagnosed.

Objective To analyze the influence from material and size of the filling block on stress distributions of the tibial osteotomy model. Methods The filling blocks with three different materials (iliac bone, cancellous bone and polyetheretherketone (PEEK)) and five different sizes were established and implanted to the tibial osteotomy models, respectively. The mechanical loads were applied on the model, the stress distribution and edge displacement of the model were analyzed. Results For three kinds of materials, the stress at proximal end of the tibia and the plate, as well as edge displacement in the model implanted with filling block by iliac bone material were lower than those of the cancellous bone and PEEK, but the filling block by iliac bone material had the highest stress. When the filling blocks with different sizes were implanted in osteotomy space, the stress distribution on each part of the tibial osteotomy and edge displacement were different. Especially when the width of the filling block was reduced from 30 mm to 10 mm, the peak stress of the proximal tibia, steel plate and filling block was increased by 49. 3% , 92. 7% and 54. 4% on average. Conclusions Different filling block parameters will affect the stress distribution in different parts of the tibial osteotomy. The research results provide the theoretical basis for parameter selection of the tibial osteotomy filling block in clinic.