1.Practice and experience on performing a better medical ultrasound teaching for undergraduate medical students
Lijun YUAN ; Yunyou DUAN ; Tiesheng CAO
Chinese Journal of Medical Education Research 2015;(1):38-41
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.
2.Difference of involving rate in intracranial arteries and hemodynamic in extracranial arteries between child and adult moyamoya disease
Litao RUANG ; Yunyou DUAN ; Tiesheng CAO
Chinese Journal of Ultrasonography 2003;0(07):-
Objective To explore the difference of invovling rate in intracranial arteries and hemodynamics in extracranial arteries between child group and adult group moyamoya disease.Methods In order to differentiate the child and adult group moyamoya disease,the hemodynamic parameters such as pulse index(PI), resistance index(RI), mean velocity(Vm),systolic velocity/distolic velocity(S/D) were studied by ultrasound and the involving rate of intercranial arteries were studied by digital subtraction angiography.Results ① The involving rate of posterior cerebral artery(PCA) in child group was signifiicantly higher than that in adult group,but no difference in middle cerbral artery(MCA) and anterior cerebral artery(ACA); ② The mean flow velocity of vertebra artery(VA) were significantly reduced but RI,PI,S/D increased in child group than that in adult group moyamoya disease.No difference existed in other extracranial arteries.Conclusions The difference of extracranial arteries hemodynamics owes to the difference of intracranial artery involving rate.
3.Ultrastructural changes of external iliac arteries in hyperhomocysteinemia rabbits with endothelial dysfunction
Litao RUAN ; Tiesheng CAO ; Yunyou DUAN
Chinese Journal of Ultrasonography 2003;0(12):-
Objective Through transmission electron microsco pe to observe the ultrastructural changes in external iliac arteries of hyperhomocysteinemia rabbits with endothelial dysfunction.Methods Eighteen rabbits were randomized into two groups (n=9 per group).Control group (N group) was poured water into stomach,Methionine group (M group) were poured L-methionine ( 5.0 g/kg weight) into stomach.Endothelium-dependent dilation (EDD),endothelium-independent dilation (EID) were examined by high resolution ultrasound at 0,4,8,12,24 h,at same time and external iliac arteries were observed by transmission electron microscope after 24 h.Results ① In acute hyperhomocysteinemia,EDD of external iliac artery in M group was time-dependent reduced more significantly than that in N group,but EID was not affected. ② Under transmission electron microscope,external iliac arteries of rabbits showed endothelial cells dropping,mitochondrion swelling in endothelial cells and smooth muscle cells,internal elastic lamina disruption,migration of smooth muscle cell to subendothelial space.Conclusions In hyperhomocysteinemia,homocysteine could lead to endothelial dysfunction in rabbits and ultrastructural damage of endothelial cells,smooth muscle cells and internal elastic lamina.High resolution ultrasound could find the endothelial dysfunction accurately.
4.Effects of respiration on hemodynamics in patients with pericardial effusion by color Dopplere chocardiography
Lijun YUAN ; Tiesheng CAO ; Yunyou DUAN
Chinese Journal of Ultrasonography 1993;0(02):-
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
5.Influence of cardiac motion on the velocity-time integrals of Doppler flow spectra: in vitro model study
Kang DING ; Tiesheng CAO ; Yunyou DUAN
Chinese Journal of Ultrasonography 1993;0(04):-
Objective To investigate the influence of simulated heart motion on the Doppler spectrum velocity- time integral (VTI) of simulated blood flow measurements through an in vitro model. Methods Using heart-motion simulator model TD-3 designed by ourselves to note the feature of Doppler spectrum of simulated heart and simulated blood flow which moved separately and synchronously.The affection of the simulated heart's motion on the VTI of the simulated blood flow and their quantitative relationship were observed.Results When the simulated heart and blood flow moved synchronously, the VTI of the combined motion was the algebra sum of their VTI when their motion independently. The velocity and frequency of Doppler spectrum of simulated heart were unchanged. Conclusions The motion of simulated heart has a great influence on the value of Doppler blood flow spectrum VTI and this effect should be considered when blood flow volume was measured using Doppler's methods.
6.Preliminary study on effect of cardiac cycle and respiratory motion on Doppler flow spectrum of common femoral venous in healthy adults
Kang DING ; Tiesheng CAO ; Yunyou DUAN
Chinese Journal of Ultrasonography 2003;0(05):-
Objective To evaluate the nature of Doppler flow spectrum of normal lower limb venous and to assess the influence of respiratory and cardiac cycle on it. Methods The right common femoral veins of 32 healthy adults were evaluated by pulsed wave Doppler with simultaneous electrocardiogram and respiratory tracing. Results In normal respiration,the Doppler spectrum of common femoral vein was divided into three types. Type C(“C” is for cardiac) displayed a wave rhythm which shared similarity with the heart beat and consists of atrial systolic (a),systolic (s) and diastolic (d) wave. Cardiac waveforms were modulated by respiratory motion: during expiration,the velocity of s,d wave gradually increased and during inspiration gradually decreased,and a wave was on the opposite. Type R(“R” is for respiration) displayed a waveform which is in harmony with respiratory signal basically. Type CR displayed a waveform which is an integration of type C and type R. Conclusions During quiet respiration,lower limb venous Doppler flow spectrum is influenced both by respiratory and cardiac cycle. The appreciation of this phenomenon would be instructive on analyzing the Doppler spectrum of lower limb venous in normal and pathological condition.
7.Value of measurement of aortomesenteric angle in diagnosis and treatment of varicocele
Litao RUAN ; Yunyou DUAN ; Tiesheng CAO
Chinese Journal of Ultrasonography 2003;0(07):-
Objective To study the value of measurement of aortomesenteric angle in diagnosis and treatment of varicocele. Methods Fifteen varicocele patients with testicular vein diameters greater than 3 mm were studied,the aortomesenteric angles and the velocity of bilateral renal veins were measured. Results The aortomesenteric angle in varicocele patients with testicular vein diameters greater than 3 mm was significantly greater than that of control group( 36.31 ?? 8.55 ?vs 25.58 ?? 9.02 ?,P
8.Ultrasonographic observations on proliferative activity and invasiveness of rabbit renal VX_2 tumor
Wen WANG ; Yunyou DUAN ; Tiesheng CAO
Chinese Journal of Ultrasonography 2003;0(08):-
Objective To explore the correlation between the ultrasonographic parameters describing the tumor and proliferative activity, invasiveness of the rabbit renal VX 2 tumor. Methods Animal models were established in 56 rabbits,in which left kidneys were transplanted with VX 2 tumor. The second harmonic imaging and video-density quantitative determination were applied to observe the size, echo-intensity and edge echo-pattern of the rabbit renal VX 2 tumor. The findings were compared with those of histopathologic section and DNA analysis calculated with the flow cytometer. Results The number of tumor cell with higher proliferative index(PI) and ploidy cell rate(PCR) increased with the tumor size. The tumors of hyperecho and more blood flow with obvious necrosis tissue, fibrotic lesion and blood sinusoid got higher PI and PCR than the tumors of hypoecho and less blood flow, while there was no statistic significant correlation between the echoic patterns of the tumor edge and DNA analysis.Conclusions The ultrasonographic parameters describing the tumor, such as the size, echo-intensity and blood flow, can be used to evaluate the proliferative activity and invasiveness of the renal tumor.
10.Cinical Evaluation of Transesophageal Echocardiography Applied to Diagnose the Mediastinal Teratoma
Weiwei ZHOU ; Yunyou DUAN ; Tiesheng CAO
Journal of Chinese Physician 2001;0(02):-
Objective To probe the clinical value of transesophageal echocardiography(TEE) in diagnoses of mediastinal teratoma.Method Differential diagnosis of benign or malignant tumor was carried out on the bases of echocharacteristics,size,capsule lesion,boundary,growing speed,invasion and compression of tumor etc with TEE in twenty cases of mediastinal teratoma.Results The sensitivity,specificity and accuracy of the TEE diagnosis for mediastinal teratoma were 70%,94%,90% respectively.Conclusion TEE has an important value for diagnosis of mediastinal teratoma.