Yunyou Duan

Fourth Military Medical University, Xi’an, Liaoning, China

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Publications (14)30.01 Total impact

  • Hengli Yang · Wenbin Cai · Lei Xu · Xiuhua Lv · Youbei Qiao · Pan Li · Hong Wu · Yilin Yang · Li Zhang · Yunyou Duan ·
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    ABSTRACT: Nanobubbles (NBs), as novel ultrasound contrast agents (UCAs), have attracted increasing attention in the field of molecular ultrasound imaging for tumors. However, the preparation of uniform-sized NBs is considered to be controversial, and poor tumor selectivity in in vivo imaging has been reported. In this study, we fabricated uniform nano-sized NBs (478.2 ± 29.7 nm with polydispersity index of 0.164 ± 0.044, n = 3) using a thin-film hydration method by controlling the thickness of phospholipid films; we then conjugated the NBs with Affibody molecules to produce nano-sized UCAs referred to as NB–Affibody with specific affinity to human epidermal growth factor receptor type 2 (HER2)-overexpressing tumors. NB–Affibody presented good ultrasound enhancement, demonstrating a peak intensity of 104.5 ± 2.1 dB under ultrasound contrast scanning. Ex vivo experiments further confirmed that the NB–Affibody conjugates were capable of targeting HER2-expressing tumor cells in vivo with high affinity. The newly prepared nano-sized NB–Affibody conjugates were observed to be novel targeted UCAs for efficient and safe specific molecular imaging and may have potential applications in early cancer quantitative diagnosis and targeted therapy in the future.
    Biomaterials 10/2014; 37. DOI:10.1016/j.biomaterials.2014.10.013 · 8.56 Impact Factor
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    Li Zhang · Jikai Yin · Yunyou Duan · Yilin Yang · Lijun Yuan · Tiesheng Cao ·
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    ABSTRACT: Abnormality of hepatic vein (HV) waveforms evaluated by Doppler ultrasonography has been widely studied in patients with chronic liver disease. We investigated the correlation between changes in HV waveforms and portal vein velocity (PVVel), the hepatic artery pulsatility index (HAPI), and also the extent of abnormal Doppler HV waveforms expressed as damping index (DI), severity of portal hypertension expressed as Child-Pugh scores and portal pressure (PP) measured directly from patients with portal hypertension (PHT) to evaluate the indicative value of abnormal HV waveforms and discuss the cause of abnormal HV waveform. Sixty patients who had been diagnosed with PHT and accepted surgical therapy of portosystemic shunts were investigated. PP was measured intraoperatively. Thirty healthy volunteers with no history of chronic liver disease were enrolled as the control group. HV waveforms were categorized as triphasic, biphasic or monophasic. DI was compared as the quantitative indicator of abnormal HV waveforms. Another two Doppler parameters, PVVel and HAPI were also measured. These Doppler features were compared with PP, Child-Pugh scores and histological changes assessed by liver biopsy. In the patient group, the Doppler flow waveforms in the middle HV were triphasic in 31.6%, biphasic in 46.7%, and monophasic in 21.6% of subjects. These figures were 86.7%, 10.0%, and 3.3%, respectively, in healthy subjects. With the flattening of HV waveforms, the HAPI increased significantly (r = 00.438, p < 0.0001), whereas PVVel decreased significantly (r = -0.44, p <0.0001). Blood flow parameters, HAPI, PVVel and HV-waveform changes showed no significant correlations with Child-Pugh scores. The latter showed a significant correlation with PP (r = 0.589, p = 0.044). Changes of HV waveform and DI significantly correlated with PP (r = 0.579, r = 0.473, p <0.0001), and significant correlation between DI and Child-Pugh scores was observed (r = 0.411, p = 0.001). PP was significantly different with respect to nodule size (p < 0.05), but HV-waveform changes were not significantly correlated with pathological changes. In patients with PHT, a monophasic HV waveform indicates higher portal pressure. Furthermore, quantitative indicator DI can reflect both higher portal pressure and more severe liver dysfunction. Flattening of HV waveforms accompanied by an increase in the HAPI and decrease in PVVel support the hypothesis that histological changes reducing HV compliance be the cause of abnormality of Doppler HV waveforms from the hemodynamic angle.
    BMC Gastroenterology 07/2011; 11(1):84. DOI:10.1186/1471-230X-11-84 · 2.37 Impact Factor

  • Ultrasound in Medicine & Biology 08/2009; 35(8). DOI:10.1016/j.ultrasmedbio.2009.06.525 · 2.21 Impact Factor
  • Xianghong Luo · Tiesheng Cao · Zhaojun Li · Yunyou Duan ·
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    ABSTRACT: In normal subjects there is a certain corresponding relationship between the peak rotation angle of the apex and the base with respect to the phase of the cardiac cycle. We hypothesized that the myocardial contractile force and the delay of conduction may affect the correspondence of them. Our study aims to use speckle tracking imaging (STI) technique to analyze the relationship between the left ventricular rotation/torsion (LVrot/ LVtor ) characteristics and cardiac cycle phase, to investigate its clinical feasibility. The echocardiographic images of the short-axis view of the left ventricles (LV) at the apical and basal planes were acquired by STI in 32 healthy controls and 48 heart failure patients (New York Heart Association class I or II). LVtor angle, LVrot angle, the peak value and time of LVtor and LVrot were measured offline using frame-to-frame tracking of gray-scale speckle patterns at the standardized time point, respectively. All the acquired data of the two groups were compared and analyzed. In the healthy controls, there was no significant difference among the isovolumetric contraction time, peak time of clockwise rotation at the apical level and the peak time of clockwise rotation at the basal level segments (P > 0.05). There was no significant difference among systolic time, peak time of counterclockwise rotation at the apical level and peak time of counterclockwise rotation at the basal level segments (P > 0.05). There was no significant difference between systolic time and peak time of LVtor (P > 0.05). Compared with normal group, the peak of LVtor and LVrot angle were decreased at both apical and basal planes in heart failure group (P < 0.05). The peak time of LVtor was delayed in heart failure group (P < 0.05). The peak time of clockwise rotation at the apical level segments was longer than control group (P < 0.05) and continued to the ejection period. In the normal subjects, there is no sequence difference of LVrot between the basal and apical planes. They were correspondent to cardiac cycle. There is a temporal sequence difference of LVrot between basal and apical planes during LV contraction in heart failure group and decreased LVtor/rot have been demonstrated to influence left ventricular function. STI has shown great potential in early detecting the conduction variability in ventricular wall.
    The international journal of cardiovascular imaging 05/2009; 25(6):559-68. DOI:10.1007/s10554-009-9462-1 · 1.81 Impact Factor
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    Junhong Chen · Tiesheng Cao · Yunyou Duan · Lijun Yuan · Zuojun Wang ·
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    ABSTRACT: To date, most studies about strain and strain rate (SR) are based on Doppler tissue imaging (DTI), which is dependent on the angle between ultrasonic scan line and tissue. Velocity vector imaging (VVI) is a new echocardiographic method based on two-dimensional gray scale imaging, which is angle-independent and can provide more information about cardiac function than DTI. To assess regional myocardial SR in hypertensive patients with left ventricular hypertrophy (LVH) but normal global ejection fraction (GEF) and fractional shortening (FS) using VVI. Using VVI, two-dimensional images were performed in 20 hypertensive patients with LVH and 20 normal control subjects. The segmental systolic peak SR (SRs) in the short-axis view and the apical SRs in the long-axis view were analyzed by offline software. The segmental SRs in the long-axis and short-axis views were significantly lower in the LVH group than in the corresponding segments of the control group. There was no significant difference between the circumferential SRs of different segments in the short-axis view in the LVH and control groups. The circumferential SRs decreased significantly from the endocardium to the middle layer of the myocardium in the short-axis view in the LVH group and in the control group. Hypertensive patients with LVH may have regional LV systolic function impairment despite having normal GEF and FS. The GEF and FS were not the decisive factors of myocardial systolic function in the present study. There was an obvious systolic gradient from the endocardium to the middle layer of myocardium in circumferential SRs in the short-axis view. VVI can be used to accurately recognize and quantify abnormalities of regional myocardial deformation.
    The Canadian journal of cardiology 11/2007; 23(12):957-61. DOI:10.1016/S0828-282X(07)70857-7 · 3.71 Impact Factor
  • Junhong Chen · Tiesheng Cao · Yunyou Duan · Lijun Yuan · Yong Yang ·
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    ABSTRACT: To assess the regional systolic function in patients with post myocardial infarction (PMI), using the velocity vector imaging (VVI) technique, a new two-dimensional echocardiographic method. Two-dimensional images of apical four, two chambers and apical long-axis view were obtained in 20 patients with PMI and 15 normal controls. The segmental myocardial systolic peak strain (epsilon), strain rate (SRs), and segmental ejection fraction (SEF) were analyzed with VVI offline software. The result of epsilon in middle segments of the normal control analyzed by VVI was compared with that by tissue Doppler imaging (DTI). The segmental epsilon, SRs, and SEF were significantly lower in infarct segments than in the corresponding segments of the normal controls. There were significant difference in average epsilon, SRs, and SEF among infarct, noninfarct, and normal control segments. The segmental epsilon, SRs, and SEF did not vary significantly from basal to apical segments in the normal control subjects. There was a good correlation on epsilon in middle segments between VVI and DTI (r = 0.710, P < 0.01). The interobserver variability was 4.6% and the intraobserver variability was 7.0%, respectively. The regional systolic function decreased in infarct segments compared with the adjacent noninfarct segments and normal control segments. The systolic function of adjacent noninfarct area was also affected by infarct areas. VVI could recognize and quantify the abnormality of infarct segments and therefore could be a useful tool in assessing the myocardial regional systolic function.
    Echocardiography 10/2007; 24(9):940-5. DOI:10.1111/j.1540-8175.2007.00492.x · 1.25 Impact Factor
  • Guozhen Yan · Yunyou Duan · Litao Ruan · YiLin Yang · TieSheng Cao ·
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    ABSTRACT: The fibrosis models were constructed in the experimental rats which underwent complex fibrosis models methods, and the aim was to assess the value of noninvasive ultrasonography quantitative scoring system in the diagnosis of hepatic fibrosis using high-frequency ultrasonography unit. Thirty-five male rats were included in this study. The fibrosis models were constructed in the 35 experimental rats which underwent complex fibrosis models methods. Ultrasonography, serum fibrosis markers were submitted in week 0, week 2, week 4, and week 6, during the construction of fibrosis models, which were also detected with pathological diagnosis. Ultrasonography quantitative scoring system was used to discriminate the degree of hepatic fibrosis, and the results were compared with pathological diagnosis. The complex fibrosis models methods can be used to construct hepatic fibrosis model. The ultrasonography quantitative scoring system had a higher relativity to pathological stage (r=0.86), when it was combined with serum fibrosis markers, the sensitivity (96.5%) and specificity (95.8%) were increased. High-frequency ultrasonography appears to be an efficient tool allowing new possibilities to use this animal model, ultrasonography quantitative scoring system, especially when it was combined with CT, serum fibrosis markers, had a higher value in noninvasive quantitative diagnosis of hepatic fibrosis in longitudinal studies, which are much more powerful.
    Hepato-gastroenterology 10/2007; 54(79):1908-14. · 0.93 Impact Factor
  • Lijun Yuan · Tiesheng Cao · Yimin Zang · Jianming Pei · Yunyou Duan · Feng Gao ·
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    ABSTRACT: It is well known that left ventricular (LV) filling decreases on inspiration and increases on expiration; however, respiratory effects on diastolic function have not been fully investigated. This study attempted to provide further information on the precise diagnosis of LV diastolic dysfunction when taking respiration into account. Fifty-one patients with systemic hypertension and impaired LV diastolic function and 33 normal subjects were recruited. Respiratory transmitral Doppler flow parameters and the early-to-late diastolic tissue velocity ratio of the mitral annulus (e/a ratio) of the septal wall were recorded. The validity of the reversal ratio of early-to-late peak flow velocity (E/A ratio) on inspiration and on expiration for diagnosis of diastolic dysfunction was compared. The E velocity was much higher and its deceleration time was much shorter on expiration compared to that on inspiration, while the A velocity demonstrated no regular respiratory variations both in normal subjects and patients. Ten of the patients displayed a phenomenon characterized with an E/A ratio < 1 on inspiration and > 1 on expiration, eight of whom revealed abnormal LV filling by Tissue Doppler imaging. Respiratory effects on transmitral Doppler flow parameters raise the necessity of adjustment of the existing standard for precise diagnosis of diastolic dysfunction, while the characteristic phenomenon reported here indicates that reversal E/A value on end-inspiration is a more sensitive and accurate indicator of abnormal LV diastolic function.
    Echocardiography 05/2007; 24(5):472-7. DOI:10.1111/j.1540-8175.2007.00433.x · 1.25 Impact Factor
  • Lijun Yuan · Yunyou Duan · Tiesheng Cao ·
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    ABSTRACT: To detect Doppler ultrasonographic velocimetry alterations of renal main arteries in pregnancy-induced hypertension (PIH). The peak systolic and end-diastolic velocities (Vs, Vd), resistivity and pulsatility indices (RI, PI), systolic/diastolic ratio (S/D ratio), acceleration time (AT) and systolic acceleration (SA) of renal main arteries were obtained in 17 PIH women and 15 age- and gestation week-matched normal pregnant (NP) women. The data between the two groups were compared with unpaired student's t-test. The AT was much longer and SA much lower in PIH than those in NP, while no significant differences were found in Vs, Vd, RI, PI and S/D ratio. AT and SA could be better used than Vs, Vd, RI, PI or S/D for detection of hemodynamic changes of renal arteries in patients with PIH. It may also imply that larger arteries proximal to the renal main artery be significantly affected.
    European Journal of Obstetrics & Gynecology and Reproductive Biology 04/2007; 131(1):36-9. DOI:10.1016/j.ejogrb.2006.04.019 · 1.70 Impact Factor
  • Lijun Yuan · Yunyou Duan · Tiesheng Cao ·
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    ABSTRACT: To investigate the cardiac morphological and functional changes by echocardiography, before and after parturition in patients with pregnancy-induced hypertension (PIH). The parameters related to cardiac morphology and left ventricular diastolic and systolic functions were compared before and after parturition in 32 patients with PIH and 24 normal pregnant (NP) women. Compared with NP women, the PIH patients had greater diameters of left atrium and left ventricle in end-diastole (LAd: 38.9 +/- 4.5 vs 34.6 +/- 4.4 mm, P = 0.0015; LVEDd: 51.2 +/- 5.8 vs 47.1 +/- 4.2 mm, P = 0.036) and lower E/A (1.2 +/- 0.2 vs 1.4 +/- 0.2, P = 0.009) and greater fractional shortening (FS) (39.8 +/- 6.5% vs 37.1 +/- 6.9%, P = 0.042) and ejection fraction (EF) (0.72 +/- 0.07 vs 0.66 +/- 0.08, P = 0.040). Pericardial effusion (PE) occurred in 31.3% and 16.7% of PIH and NP, respectively. The LAd and LVEDd in 70% and 47% patients with PIH resolved and PE disappeared in 80% of PIH patients postpartum. E/A ratio in PIH significantly increased after parturition, while the two patients with cardiac systolic dysfunction did not improve very much. Compared with normal pregnancy, the most significant cardiac morphological changes in PIH are the greater diameters of left atrium and left ventricle, thicker inter-ventricular septum (IVS), more PE, impaired left ventricular diastolic function, and increased systolic function. The PE could disappear in PIH and about half of other abnormalities could recover to be the level of normal pregnancy postpartum within 2 months.
    Echocardiography 04/2006; 23(3):177-82. DOI:10.1111/j.1540-8175.2006.00203.x · 1.25 Impact Factor
  • Guozhen Yan · Yunyou Duan · Litao Ruan · Tiesheng Chao · Yilin Yang ·
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    ABSTRACT: This article aimed to compare ultrasonography score with CTP score and MELD score, as well as, describe the possibility of a noninvasive diagnosis of the degree of hepatic fibrosis using the various imaging techniques and provide suggestions for daily clinical practice. A total of 53 patients (33 male and 20 female) admitted to our Hospital between March 2004 and March 2005, were included in this preliminary study. Twenty-five age-matched healthy persons (17 male, 8 female) served as controls. The ultrasound quantitative scoring system was applied in this test which was established according to the previous researcher. All the patients and control group underwent ultrasonography and CT examination. CTP and MELD score were calculated using standard formula. The ultrasound quantitative scoring system, as well as CTP, and MELD score had a higher relativity to pathological stage. Correlations between ultrasonography score, CTP, and MELD score were assessed by the Spearman correlation coefficient. Correlation coefficient was 0.784, and 0.768 respectively. Ultrasound can be recommended as one of the choices for noninvasive diagnosis of hepatic fibrosis for its advantages. Increasing CTP (less than 10) and MELD score correlated with progressive impairment of liver function as evaluated by means of a blood flow-dependent quantitative liver function test.
    Hepato-gastroenterology 09/2005; 52(65):1329-33. · 0.93 Impact Factor
  • Yunyou Duan · Xi Liu · Xiaoyan Zhou · Tiesheng Cao · Litao Ruan · Yali Zhao ·
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    ABSTRACT: The purpose of this study was to observe image characteristics and hemodynamic changes of carotid-cavernous sinus fistulas (CCFs) and to evaluate the efficacy of interventional treatment for CCFs by color Doppler ultrasonography (CDUS). Thirty-three patients with suspected CCFs were studied with CDUS. Forty-six volunteers took part in this study as controls. Scanning was performed through temporal, orbital, and occipital windows to measure the blood flow parameters of the internal carotid artery (ICA) and related vessels. All results were confirmed by cerebral angiography. Nineteen patients were followed after interventional treatment. Thirty-two patients (97%) were found to have CCFs by CDUS. Irregular mosaic flashes were observed in the cavernous sinus region, the cross-section areas of which were significantly larger than those of the normal intracranial ICA (1.7-5.2 versus 0.2-0.5 cm(2); P < .01). A lower resistive index of the ICA in the affected side was revealed with spectral analysis of relevant vessels. The peak velocity of vessels distal to the fistula was significantly lower than that of the healthy side and control group (P < .05). Superior ophthalmic veins had a reversed arterialized flow pattern with a mean velocity of 34.5 cm/s and an average resistive index +/- SD of 0.31 +/- 0.08. In follow-up study, the mosaic flashes and turbulence flow disappeared in 14 patients and remained in 5 after the interventional operation. Combined with the direct sign of an irregular mosaic flash in the cavernous sinus region, hemodynamic changes in relevant branch vessels, and a reversed arterialized flow pattern in superior ophthalmic veins, CDUS has great value in confirming diagnosis and follow-up study of CCFs.
    Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 06/2005; 24(6):739-45. · 1.54 Impact Factor
  • Huaping Jia · Yunyou Duan · Tiesheng Cao · Baishan Zhao · Faqin Lv · Lijun Yuan ·
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    ABSTRACT: The objective of this article is to evaluate the safety of diagnostic color Doppler ultrasound (CDUS) on embryos by observing its effects on myocardial cell apoptosis of fetal rats. Pregnant Sprague-Dawley rats were divided into fetal group and neonatal group according to the sample-drawing time averagely and randomly, and each group was subdivided into control group and insonification group. The control group was sham-insonificated, and the insonification group was insonificated by diagnostic ultrasound (3.0 MHz, Tis = 1.8, MI = 1.6) for 30 minutes. The fetal rats' hearts were removed 24 hours after insonification and the neonatal rats' hearts were removed 10 days after birth. Apoptosis cells were detected with TUNEL (in situ terminal deoxynucleotidyl transferase-mediated D-UTP nick end labeling), and ultrastructural changes were observed with transmission electron microscope. Myocardial cell apoptosis was significantly higher in the fetal insonification group than in the fetal control group (P < 0.05), and it was significantly higher in the fetal groups than in the neonatal groups (P < 0.05), but there was no significant difference in myocardial cell apoptosis between the neonatal groups (P < 0.05). Apoptotic changes of myocardial cells in the fetal insonification group were observed with transmission electron microscope, which showed margination, condensation of the nuclear chromatin, etc. It is concluded that apoptosis and ultrastructural changes could be induced if fetal rat's heart was irradiated continuously over 30 minutes by diagnostic CDUS, but this phenomenon would disappear after birth.
    Echocardiography 05/2005; 22(5):415-20. DOI:10.1111/j.1540-8175.2005.04035.x · 1.25 Impact Factor
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    ABSTRACT: The aim of our study is to quantitatively investigate influence of the intrathoracic pressure change on the four cardiac valves' velocities and further verify a new proposal of the mechanism of respiratory influence on hemodynamics. Methods: Thirty healthy volunteers with no cardiopulmonary diseases were included. The intrathoracic pressure changes were measured with self-designed device. The velocity across the four cardiac valves during spontaneous respiration and with the intrathoracic pressure change at -4, -8, and -12 mmHg, respectively, were recorded simultaneously with the electrocardiogram and respiratory curve. The respiratory variation indices (RVIs) were calculated. The average RVIs of mitral, aortic, tricuspid, and pulmonary valves were 12.54%, 13.19%; 6.23%, 8.27%; 20.27%, 24.36%; and 6.45%, 7.69% with intrathoracic pressure change at -8 mmHg and -12 mmHg, respectively. All the above parameters have a significant difference from those during spontaneous respiration (P < 0.01 or P < 0.001). We concluded that it might be the respiratory intrathoracic pressure change that causes the change of the velocity across the valves.
    Echocardiography 07/2004; 21(5):391-8. DOI:10.1111/j.0742-2822.2004.03086.x · 1.25 Impact Factor