Currently, medical ultrasound teaching focuses on the delivering the image infor-mation itself, while its connection with basic medicine and clinical medicine is neglected. Such a teaching method is not good for students to establish a systemic view. To conduct the ultrasound medi-cine education effectively in undergraduate students, we have tried some reforms, including: perform-ing diseases or problem based teaching, integrating basic medicine, ultrasound medicine and clinical medicine throughout the whole teaching process, providing as many practice opportunities as possible for the graduates and integrating the ultrasound imaging with other medical imaging modalities. The practice shows that with the reform, the students have a better understanding of ultrasonic knowledge itself, a better grasp of the whole medical knowledge structure, and also have a preliminary impression on how to diagnose the disease through reasonable application of different treatments. In addition, students have more passion for study.

ObjectiveTo observe and quantify the effec ts of respiration on hemodynamics in patients with pericardial effusion (PE) and to verify our new proposed hypothesis about the mechanism of respiratory effects on cardiac function from clinical point of view. MethodsPulsed-wave Doppler spectra of the four cardiac valves were recorded with Acuson Sequoia 512 and 128 XP/10 in 10 patients with PE and 18 healthy control subjects with no apparent cardiac and pulmonary abnormalities. Electrocardiogram and respiratory tracing by a nasal thermistor were recorded simultaneously with the echocardiograms. The blood flow velocities of each valve during inspiration and expiration were averaged separately and those were again averaged for 5 consecutive respiratory cycles, and the respiratory variation indices (RVI) were calculated both in the patients and the control groups. ResultsThe peak E velocity across the mitral valve and that across the aortic valve significantly increased during expiration and decreased during inspiration, while that across the tricuspid valve and that across the pulmonary valve increased remarkably during inspiration and decreased during expiration in all of the subjects. The RVI of the velocities across the mitral and the aortic valves increased significantly in the patients with PE compared with the control subjects [MV: ( 14.57 ? 7.89 )% vs ( 9.71 ? 3.39 )%, P

0.05). Conclusions Ultrasound contrast agent Levovist improves signal of blood flow obviously. It increases the diagnostic accuracy for intracranial aneurysms and the level of confidence.

Objective To observe characteristic imaging of traumatic arteriovenous fistulas(TAVF) and to evaluate the methods of differential diagnosis of TAVF by Doppler ultrasonography. Methods Eleven patients suffering from TAVF were selected to have the examination of Doppler ultrasonography. The blood flow of arteriovenous fistulas, diameter, morphology and blood flow character of affected vessels were observed. Spectral of fistula and affected vessels were analyzed and compared with the healthy side. Results Localization of arteriovenous fistulas was observed directly in eight patients, which presented as intercepted wall of the affected vessels and irregular mosaic flashes flowing towards enlarged vein from artery. Pulsed wave Doppler showed unilateral continuant spectral with maximum velocity 300-390 cm/s when sampled in the fistula. Spectral analysis of proximal arteries of the fistula revealed high velocity and low resistance. Arterialized flow pattern was observed in affected veins. Proximal veins of the fistula revealed arterialized spectral with high velocity and low resistance. Reversed centrifugal blood flow was observed in the distal veins of the fistulas in 4 cases. Conclusions Unilateral shunt in both diastole and systole in the fistula and arterialized flow with high velocity in veins are characteristic presentation of TAVF. Color Doppler ultrasonography has great value in confirming diagnosis and differential diagnosis of TAVF.

Objective To evaluate the clinical effect and safety of umbilical cord ligation in the fetocide of complicated monochorionic multiple gestations.Methods From January 2009 to December 2012,clinical data of 18 women with complicated monochorionic multiple gestations who experienced intrauterine percutaneous umbilical cord ligation in Peking University Third Hospital were collected.Among the patients,6 were selective intrauterine growth restriction (1 with type Ⅰ,4 with type Ⅱ,1 with type Ⅲ) ; 4 were acrania or hydropic twins; 4 were aeardiac twins,2 were complicated triplet gestation; 1 was twin-twin transfusion syndrome with right ventricular dysplasia and 1 was monochorionic diamniotic (MCDA) with caesarean section history.The procedure was performed under both endoscopic and sonographic guidance.The gestational age at the time of the procedure were 17-27 +6 weeks.The procedure and perinatal outcome were analyzed.Results (1) The procedure was performed successfully in all the 18 cases.The average duration of the procedure was 63 min (24-156 min).The blood loss was 7.6 ml (5-20 ml).The mean gestational age at the time of the procedure was 20 weeks (17-27 +6 weeks).The average birth weight of the neonates was 2441 g(1000-3400 g).(2) There were 20 fetuses survived.Two fetuses had cardiac anomalies and were terminated in the following 2-3 weeks.Intrauterus fetal demise occured in 3 twin reverse arterial perfusion syndrome (TRAP) cases 3-14 weeks after the procedure.1 case delivered as early preterm birth at 28 weeks and the neonate died of respiratory distress syndrome (RDS) and hypoxie-ischemicencephalopathy (HIE).Fourteen neonates were in healthy and normal development by 3-51 months' followup.(3) Fourteen cases delivered at more than 28 weeks (28-38 weeks,averagely 33 + 1 weeks).The gestational weeks were prolonged by 5-21 weeks (averagely 13 +4 weeks).Among them,3 case were early preterm birth (28-33 weeks) and 3 were late preterm birth (34-36 weeks).Conclusion Percutaneous umbilical cord ligation is a reliable technique for the fetocide of complicated monochrionic mutilple gestations,especially for monochronic monoamniotie pregnancies.

Objective To reveal the exact mechanical principle of the respiration-driven variation of cardiac function by observing the effect of respiratory intrathoracic pressure change (RIPC) on the mechanical models using echocardiography.Methods Model 1 was designed to observe the influence of RIPC on systemic and pulmonary venous return systems (SVR and PVR) respectively.Model 2,as an equivalent mechanical model of septal swing,was used to study the influence of RIPC on the motion of the interventricular septum (IVS).Results Model 1 demonstrated that the simulated RIPC had totally different influences on the simulated SVR and PVR.It increased the volume of the simulated right ventricle when the internal pressure was kept constant (8.16 cm H2O),while it had the opposite effect on PVR.Model 2demonstrated that there was a corresponding relationship between RIPC and the position of the simulated IVS which might be called pressure-position relationship.Conclusions The different anatomical arrangement of the two venous return systems leads to a different effect of RIPC on right and left ventricles,and thus generates a pressure gradient across IVS that tends to shift IVS left-and right-wards with respiration.The swing of the IVS changes the short axis diameters of the ventricles,thus their fillings and then their functions reciprocally.

Objective To observe any change in the active volume of the hand motor cortex during rehabilitation therapy after acute cerebral infarction and analyze the mechanisms involved in motor function rehabilitation.Metbods Of 16 patients with acute brain infarction,8 were administered routine intemal medicine treatment only,while and the other 8 received rehabilitation therapy in addition.Before treatment and after 14 days,the patients were assessed with functional magnetic resonance imaging(fMRI)and the Fugl-Meyer assessment of motor function (FMA).The active volume of the motor cortex was compared between the two groups of patients.Ten healthy volunteers were examined with fMRI to confirm the location and the volume ofthe active area when performing the sanle exercises.Results After treatment,all the 16 patients showed increased motor cortex active volume,and their FMA scores also increased.Those receiving rehabilitation therapy improved tO a significantly greater extent than those treated with internal medicine treatment alone.Conclusion Rehabilitation of patients with acute infarction Can activate a greater volume of the motor cortex and promote functional recovery.

Objective To study the characteristics of the hand motor cortex in ataxia patients during active and passive finger-to-thumb opposition movements using bold oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI). Methods Ten right-handed healthy volunteers and 16 ataxia patients with motor cortex lesions were selected, and whole-brain BOLD-fMRI examinations were made while the subjects were performing the active and passive movements. Activated volume and intensity were recorded from the corresponding motor cortex and analyzed quantitatively. Meanwhile, the patients' coordination was evaluated using the international cooperative ataxia rating scale (ICARS). Results During passive movement of the ataxia patient's affected hands, the ipsilateral supplementary motor area (SMA) activated volume was larger than that during normal ipsilateral hand movement, and the activation intensity was also higher than that in the healthy controls. The ipsilateral cerebellum activated volume and intensity were significantly lower than those in the control group, and the frequency of appearance of the cerebellum was also less. The patients' activated volume and intensity in the ipsilateral cerebellum showed no correlation with ICARS scores. Conclusions When the ataxia patients' affected side cerebellum was dysfunctional, the ipsilateral SMA could compensate for the weak cerebellum function. The ICARS does not reflect cerebellum function.

Objective To observe the effects and the mechanism of the thoracic pressure variation on the velocity of tricuspid regurgitation in quiet respiration, to accurately estimate the pulmonary artery systolic pressure,and to verify the new proposed mechanism of respiration effects on hemodynamics using echocardiography. Methods Continuous-wave Doppler spectra of tricuspid regurgitation were recorded with Sequoia 512 in 50 patients who had stable tricuspid regurgitation. Electrocardiogram and respiratory tracing were recorded simultaneously. The velocities and the pressure gradients were recorded during different respiration phases for analyzing. Results Respiration reliably affected on tricuspid regurgitant velocity. There were three patterns of manifestation:①The velocity increased in the inspiratory phase. ②The velocity decreased in the inspiratory phase. ③The velocity changed randomly. Conclusions Thoracic pressure variations had definite effects on the velocity of tricuspid regurgitation and tricuspid gradient. This research indicated that to obtain accurate and reliable Doppler echocardiographic measurement of the pulmonary artery systolic pressure, the measurement should be at the time between inspiration and expiration.

Objective To investigate the association between polymorphism of TNFα-308 and mutations of HBV C region in patients with chronic HBV infection. Methods Ninety-five patients with chronic HBV infection were recruited in the study. The single nucleotide polymorphism(SNP) of TNFα-308 Was determined by restriction fragment length polymorphism(RFLP). Mutations of nt1762/1764, nt1896, nt1899, nt1862, as60, aa87 and as97 in HBV C region were detected by direct sequencing after PCR amplification. Mutations of the above points among different genotypes were compared by Fisher's exget test. Results Three different genotypes G/G(63/95, 66.3%), G/A(28/95, 29.5%) and A/A(4/95, 4.2%) were found in TNFα-308 site. The rates of mutations of aa87 and aa97 points in patients with G/G, G/A and A/A genotype were 39.3%(24/61), 11.5%(3/26) and 50.0% (2/4), respectively(F=7.658, P<0.05);while the mutation rates of nt1762/1764, nt1896, nt1864, nt1899 and aa60 were of no statistical significance among different genotypes(F=0.669, 1.542, 1.123, 2.420 and 0.966, P>0.05). Conclusion Compared with G/G genotype, antigenicity of HBV may be more stable in patients with TNFα-308 G/A genotype, which is beneficial to HBV clearance.