Objective:To explore the asymmetry of neonatal brain white matter using fractional anisotropy (FA) parameter generated from diffusion tensor imaging (DTI).Methods:From January 2011 to June 2013, 88 neonates with normal cranial MRI performance, aged 1-14 (7.7±0.3) days and gestational age 31-42 (37.5±0.3) weeks, were retrospectively collected from the First Affiliated Hospital of Xi′an Jiaotong University. According to the gestational age at birth, the neonates were divided into preterm group (37 cases) and term group (51 cases). DTI was processed to generate FA parametric maps. Tract-based spatial statistics (TBSS) was used to analyze the asymmetry in neonatal white matter. Regions of interest were placed in bilaterally symmetrical white matter tracts. The white matter tracts included the bilateral anterior thalamic radiation, corticospinal tract-posterior limb of the inner capsule (CST-IC), corticospinal tract-corona radiata, cingulum hippocampus part (CGH), inferior frontal occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF), uncinate fasciculus, superior longitudinal fasciculus temporal part (SLF-temp). The FA value was measured and asymmetry index (AI) was calculated. The independent-sample t test or Mann-Whitney U test was used to compare the AI of each tract between the preterm and term groups. Partial correlation was used to analyze the effects of neonatal gestational age and birth anthropometric measures on the asymmetry of neonate at birth. Results:The results of TBSS showed that the left lateralized areas of brain white matter in the neonatal period were mainly located in the corticospinal tract, external capsule and genu of corpus callosum. The right lateralized areas of brain white matter in the neonatal period were mainly located in the optic radiation and splenium of corpus callosum. In both the preterm and term groups, the tracts related to motor (CST-IC) and language function (ILF, SLF, SLF-temp) were left asymmetry. The CGH of the preterm and the term neonates were right asymmetry, and AI was -0.086±0.114 and -0.140±0.108 respectively, with a statistically significant difference ( t=2.27, P=0.026), while the differences of AI in the remaining tracts were not statistically significant ( P>0.05). Only gestational age was correlated with the AI of ILF ( r=0.234, P=0.033), SLF ( r=0.259, P=0.018), SLF-temp ( r=0.252, P=0.022), CST-IC ( r=0.235, P=0.033). No significant correlation was found between birthweight, head circumference, body length and AI. Conclusions:The asymmetries of brain white matter already exist in neonates aged less than two weeks. The tracts associated with motor and language function are predominantly left asymmetry.

Objective:To determine the relationship between tibial plateau stresses and malunion by exploring the changes in mechanical conduction in the knee joint after malunion of Hoffa fracture of the tibial plateau.Methods:This study selected 28 knee joint specimens treated with formalin for preservation, half of which were from male and half from female individuals with an age of (51.4±9.5) years. Their structures were intact, and flexion-extension activities normal. X-ray examinations excluded osteoporosis, tuberculosis, and diseases that could have potentially affected bone quality. The knee specimens were divided into a control group (intact tibia) ( n=4) and 6 groups of tibial plateau Hoffa fracture malunion model: 3 vertical malunion groups (groups V1, V2, and V3, with a vertical displacement of 1, 2, and 3 mm, respectively, n=4) and 3 separation malunion groups (groups S3, S5, and S7, with a separation displacement of 3, 5, and 7 mm, respectively), with half males and half females in each group. After a 600N vertical load was applied at passive knee flexions at 0°, 30°, 60°, 90°, and 120°, the stress levels in the medial and lateral compartments of the knee joint were measured using pressure-sensitive films. Results:Under a vertical load of 600 N, when the knee joint was in a neutral position (flexion of 0°), the differences in the medial and lateral tibial plateau stress values were not statistically significant between the malunion models groups and the control group ( P>0.05). When the knee flexion increased to 30°, the medial tibial plateau stress in the V3 and S7 groups was significantly greater than that in the control group ( P<0.05). At a knee flexion of 60°, the medial plateau stress was significantly greater in the V3, S5 and S7 groups than that in the control group, and the differences were significantly greater than the comparisons at a knee flexion of 30° (all P<0.05). When the knee flexion was 90°, the medial plateau stress in the V2, V3, S5 and S7 groups was significantly greater than that in the control group ( P<0.05), but the lateral tibial plateau stress in the V3 group was significantly smaller than that in the control group ( P<0.05). When the knee flexion was further increased to 120°, the differences in the medial and lateral plateau stress values were statistically significant between all the malunion groups and the control group ( P<0.05), and the differences significantly greater than the comparisons at a knee flexion of 90° (all P<0.05). Under a vertical load of 600 N, the differences in the stresses on the medial and lateral plateaus were not statistically significant between the control group and all the malunion groups at a knee flexion of 0° ( P>0.05). When the knee flexion increased to 30°, the difference between the medial and lateral stresses was not statistically significant in the control group ( P>0.05), but was statistically significant in the V3 and S7 groups ( P<0.05). When the knee flexion reached 60°, 90°, and 120°, the differences between the medial and lateral tibial plateau stresses in all the groups were statistically significant ( P<0.05). Conclusions:The peak knee stresses after malunion of Hoffa fracture of the tibial plateau correlate with the severity of malunion and knee flexion angles. The mechanical properties are not significantly different between a mild malunion knee and a normal knee, but a significant displacement (vertical displacement >2 mm and separation displacement ≥5 mm) may increase the peak knee stresses to increase the risk of knee osteoarthritis. When the severity of malunion is certain, an increase in knee flexion angle increases the difference in the peak stress between the medial and lateral tibial plateaus, thus increasing the risk of knee osteoarthritis.

Objective    To assess the feasibility and safety of percutaneous transcatheter closure of atrial septal defect (ASD) guided by transthoracic echocardiography (TTE) in outpatients. Methods    From December 2016 to June 2018, 50 simple ASD patients underwent TTE-guided transcatheter closure in the outpatient operating room of our hospital (a TTE group) including 22 males and 28 females at the age of 16-48 (27.40±6.95) years. Fifty patients with simple ASD treated with the guidance of conventional fluoroscopy during the same period were treated as a control group, including 22 males and 28 females at the age of 15-48 (28.58±6.96) years. Both groups were re-examined by TTE during follow-up at 1 month, 3 months, 6 months and 1 year. Results    The mean age, body weight, the size of ASD and occluder and success rate had no statistical difference between the two groups (P>0.05). Compared with the control group, the TTE group had significantly lower mean operation time (P<0.01) and less cost (P<0.01) since patients need not to be hospitalized. No related complications were found in the TTE group during follow-up. Conclusion    Percutaneous transcatheter closure of ASD guided by TTE appears safe and effective for outpatients, and can significantly reduce the cost.

Objective    To assess the efficacy and safety of percutaneous closure of patent ductus arteriosus (PDA) solely under echocardiography guidance. Methods    We retrospectively analyzed the clinical data of 200 patients who received the percutaneous closure of PDA under echocardiography guidance in Fuwai Hospital from August 2013 to April 2016. According the different approach, they were divided into 2 groups: a femoral artery approach group (n=143) and a femoral vein approach group (n=57). In the femoral artery approach group, there were 42 males and 101 females aged 3.20±5.63 years. In the femoral vein group, there were 10 males and 47 females aged 7.30±11.36 years. All Patients were treated by percutaneous PDA closure solely under echocardiography guidance. The follow-up was performed at one month after the operation by echocardiography, chest radiograph and electrocardiogram. Results    All 200 patients were successfully treated with percutaneous closure of PDA. The patients’ gender, in-hospital stay, rates of occluder  detachment were similar between the two groups (P>0.05). Compared with the femoral vein approach group, the femoral artery approach group had a younger age (3.20±5.63 years vs. 7.30±11.36 years, P<0.001), less body weight (14.25±11.54 kg vs. 24.25±19.14 kg, P<0.001) and shorter diameter of PDA (3.06±0.79 mm vs. 5.93±0.68 mm, P<0.001) and PDA occluders (5.43±1.00 mm vs. 12.14±0.54 mm, P<0.001), but had higher hospitalization expenses (32 108.2±3 100.2 yuan vs. 25 120.7±3 534.1 yuan, P<0.001). In the femoral vein approach group, one patient was closed under radiation guidance because guide wires could not pass through PDA. One patient in the femoral artery approach group suffered from occluder detachment at one day after operation and was cured by transthoracic minimally invasive PDA occlusion. There were no complications of occluder detachment, residual shunt, pericardial effusion or left pulmonary stenosis during the follow-up. Conclusion    Echocardiography-guided percutaneous PDA closure is safe and effective, while the proper interventional approach should be chosen by the anatomical features of PDA.