Purpose To establish myocardial infarction model in rabbits and to evaluate cardiac function and pathological changes.Materials and Methods In 35 New Zealand white rabbits, the left anterior descending branch (LAD) of the coronary artery was ligated. The cardiac function was evaluated using echocardiography, and the blood serum brain natriuretic peptide (BNP) level was examined preoperatively, on postoperative day 1, and in 1 week, 2 weeks, 4 weeks and 8 weeks for comparison. Pathological sections and HE staining were performed to observe pathological changes. Results The death rate was 28.6% (10/35). There was progressive increase in left ventricular end systolic diameter (LVESD) and left ventricular end diastolic diameter (LVEDD) at 1 week, 2 weeks and 4 weeks (P<0.05). There was progressive decrease in left ventricular ejection fraction (LVEF) and left ventricular fractional shortening fraction (LVFS) at 1 day, 1 week, 2 weeks and 4 weeks (P<0.05). The BNP level started increasing in 1 day, peaked in 1 week, then gradually decreased but remained higher than preoperative level in 8 weeks (P<0.01). Pathological section showed typical myocardial cell degeneration, necrosis, ifbrosis, calciifcation and scar formation. Conclusion This myocardial infarction model is satisfactory with signiifcant decrease of cardiac function and increase of BNP level.

Objective To investigate the value of high frequency color doppler ultrasound for screening thyroid diseases in physi-cal examination people .Methods The detectable information of thyroid diseases using high frequency color doppler ultrasound in 1 413 physical examination people was analyzed .Results A total of 588 cases of the 1 413 people were detected to have thyroid dis-eases with positive rate of 41 .61% ,and the detectable rate increased with aging .The positive rate of female (349 cases ,54 .96% ) was statistically higher than that of male(239 cases ,30 .72% ) .Within the 588 people ,111 cases were diagnosed as diffused thyroid diseases and 488 cases were diagnosed as thyroid nodules by high frequency color doppler ultrasound .Twenty cases were confirmed to have thyroid carcinoma by pathologic examination ,with 3 males and 17 females .Twelve lesions were less than 1 .0 cm in diameter and were diagnosed as microcarcinoma .The smallest lesion was 6 mm × 5 mm .Conclusion The high frequency color doppler ultra-sound was useful in screening for thyroid diseases ,especially for carcinoma ,and should be used as routine examination item .

Objective To investigate the value of conventional ultrasound combined with contrast‐enhanced ultrasound in qualitative diagnosis of benign and malignant cervical lymph nodes (LNs) .Methods Totally 129 enlarged LNs in 112 cases were performed the 2‐dimensional ,color Doppler ultrasound ,and grey‐scale contrast‐enhanced ultrasound(CEUS)examinations .LNs were divided into the benign group and malignant group according to pathologic results .The aspect ratio ,eccentric medulla or medulla de‐fect ,echo type ,blood supply distribution ,contrast‐enhancement pattern and distribution equilibriuym of contrast agent were com‐pared between the two groups .Results The most of aspect ratio in the benign LNs group were ≥ 2 ,the cortex and medulla were uniform with symmetric increase and without microcalcification ,the blood supple was mainly the non‐blood flow type or hilar type , in contrast‐enhanced ultrasound ,the majority were the early hilar and medullar enhancement ,showing the centrifugally full filling ;the most of aspect ratio in the malignant LNs group were <2 ,medulla was eccentric or loss ,partial of LNs showed the increased parenchymal echo accompanied with cystic lesion and microcalcification ,the blood supply was mainly the peripheral and mixed types ,and the non‐hilar and medulla started enhancement pattern .The ultrasonographic parameters mentioned above were statisti‐cally different between the two groups ,in which the non‐hilar and medulla started enhancement patterns had the highest sensitivity and accuracy for diagnosing malignant LNs ,the positive predictive values of these parameters were higher ,whereas the negative predictive values were lower .Conclusion The conventional ultrasound combined with contrast‐enhanced ultrasonography has a higher practical value in qualitative diagnosis of cervical LNs ;the comprehensive judgment of multiple indicators can increase the differentiating ability for benign from malignant LNs .

Objective To evaluate regional right ventricular longitudinal function in fetus using velocity vector imaging(VVI),and establish nomogram of right ventricle,Methods One hundreed and seventy healthy fetuses were divided into 5 groups according to the gestational age.Dynamic digital views of four chamber view were collected and analyzed offline.Velocity,strain and strain rate were calculated in systolic and diastolic period,respectively.Results Normal systolic and diastolic values for velocity,strain and strain rate were established.Tissue velocity gradually decreased from the base segment to the apical segment(P＜0.05),whereas strain and strain rate were stable(P＞0.05).Tissue velocity was gestationalage dependent(P＜0.05),whereas strain and strain rate were stable throughout gestation (P＞0.05).Conclusions Fetal myocardial velocity,strain and strain rate measurements are easy to obtain and reproducible.Increase in tissue velocity throughout gestation probably reflects the growth of the fetal heart,whereas intrinsic myocardial properties as measured by strain and strain rate do not change.

Objective To investigate the value of combination of B-flow imaging and spatio-temporal image correlation in prenatal diagnosis of congenital heart diseases. Methods Volume images of 50 normal fetuses and 14 fetuses with congenital heart diseases were recruited in the study. Surface mode was used to reconstruct the volume images. Results Sixty-three and twenty-six qualified volume images were obtained in 50 normal fetuses and 14 fetuses with congenital heart diseases respectively. All volume images were reconstructed successfully and showed the spacial relationship of cardiac blood vessel directly. Conclusions The combination of B-flow imaging and spatio-temporal image correlation was feasible and useful in prenatal diagnosis of congenital heart diseases.

Objective To investigate the clinical value of velocity vector imaging in the assessment of regional left ventricular longitudinal myocardial function in fetuses with gestational diabetes mellitus (GDM). Methods Digital dynamic four-chamber views of 98 fetuses with GDM and 135 normal fetuses were collected and analyzed using velocity vector imaging. The regional tissue velocity, strain and strain rate of the interventricular septum and left lateral wall were measured in systole and diastole. Results Two hundred and seven of 233 cases were analyzed successfully. Systolic velocity(Vs) and diastolic velocity(Vd)were age-dependent, Vs and Vd were both gradually decreased from the basal segment to the apical segment in the left ventricle( P ＜0. 05). The Va after 32+0 weeks and Vd after 28+0 weeks and systolic strain(S),systolic strain rate(SRs) and diastolic strain rate(SRd) in left ventricle of fetuses with GDM after 24+0weeks were obviously lower than the corresponding parameters of normal fetuses ( P ＜0. 05). Conclusions Velocity vector imaging can evaluate the fetal regional left ventricular longitudinal myocardial function.

Objective To establish the normative data of the 2D and 3D ultrasound (US)measurements of the developing fetal thymus and comparing the 2DUS and 3DUS measurements of the fetal thymus. Methods The normal fetuses' thymus of 567 cases were assessed, and maximum transverse diameter(MTD),antero posterior diameter (APD), suprainferior diameter (SID), maximum transverse area (MTA) were measured by 2DUS,and thymic volume(TV) was measured by 3DUS. Results 2DUS,3DUS assessments of the fetal thymic MTD, APD, SID, MTA and TV were possible in 541 of 567 normal singletons. The fetal thymic 2D diameters/area and 3D volume grow with the gestational age(GA) in linear correlation. The 3D-US TV measurements and GA was significantly higher than that of any individual 2DUS measurements and GA ( P ＜0.05). Conclusions This study presents the normative data of the 2DUS and 3DUS measurements of the developing fetal thymus. 3DUS fetal thymus volume is more significantly correlated to GA than the other 2DUS measurements, which indicates 3DUS measurement of the fetal thymus is more accurate than that of 2DUS.

Objective To investigate the clinical significance of velocity vector imaging(VVI)in evaluating the left ventricular(LV)segmental longitudinal systolic function in patients with coronary artery disease(CAD).Methods In 25 patients with myocardial ischemia,28 patients with myocardial infarction,26 patients with coronary lumen stenosis＜50%,according to coronary arteriography and electrocardiogram,the myocardial segments of LV were divided into 4 groups:ischemic segments group,infarcted segments group,non-ischemic segments group and normal segments group.Twenty-eight healthy subjects were selected as control group.Dynamic imaging of all subjects were collected,the systolic peak strain(Smax)and strain rate(SRmax),the time to peak strain(PTs)and the time to peak strain rate(PTsr)were measured respectively.Results Smax and SRmax of the ischemic segments and infracted segments were significantly lower than those of the control group respectively,PTs and PTsr of the ischemic segments and infracted segments were significantly longer than those of the control group respectively.Smax and SRmax of infarcted segments were significantly lower than those of the ischemic segments,there were no differences of PTs and PTsr between ischemic segments and infracted segments.Smax and SRmax cutoff of -14.08%,-0.83 s-1 for detecting ischemic segments and cutoff of -6.65%,-0.38 s-1 for detecting infracted segments,respectively,gave an optimal sensitivity and specificity.Conclusions VVI is a kind of novel noninvasive-tool to quantitatively assess LV regional systolic function in CAD patients.It is competent to differentiate between the ischemic segments and infarcted segments.

Objective To investigate the clinical value of velocity vector imaging (VVI) in the assessment of cardiac torsion in fetuses with gestational diabetes mellitus(GDM).Methods Digital dynamic four-chamber views of 98 fetuses with gestational diabetes mellitus and 135 normal fetuses were collected and analyzed using VVI.Left ventricular(LV) peak apical rotation of endocardium and epicardium at basal and apical level were measured,LV peak torsion was calculated.Results 140 of 233 cases were analyzed successfully.Direction of LV peak apical and basal rotation of endocardium and epicardium in fetus could be clockwise or counter clockwise,however apical and basal level was opposite.LV peak apical and basal rotation of endocardium and epicardium in fetus were stable throughout gestation ( P ＞ 0.05).LV peak rotation of endocardium was higher than that of epicardium in both apical and basal level.The peak rotation　in apical level of endocardium and epicardium was higher than that in basal level( P ＜0.05).LV peak　torsion of endocardium was significantly higher than that of epicardium( P ＜0.05).Compared with normal　group,LV peak rotation of endocardium and LV peak torsion in fetus with GDM were higher( P ＜0.05).　Conclusions VVI can measure the LV rotation and torsion parameters,and evaluate the cardiac function of　GDM fetus.