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find Keyword "造影剂" 22 results
  • Ultrasound microbubbles enhancing the transfection of recombinant adeno associated virus vector to retinal ganglion cells in vivo

    Objective To investigate the enhancing effect of ultrasound microbubbles on transfection of recombinant adenoassociated virus (rAAV) mediated green fluorecent protein (EGFP) gene into retinal ganglion cells (RGC) in vivo.Methods A total of 40 adult Sprague-Dawley (SD) rats were divided into four groups randomly (group A,B,C,D) with 10 rats in each. Group A was the normal control, in which the rats underwent intravitreal injection with 5 mu;l phosphate buffered solution. The rats in group B underwent intravitreal injection with 5 mu;l recombinant adenoassociated virus encoding EGFP gene (rAAV2-EGFP). The rats in group C underwent ultrasound irradiation on eyes right after intravitreal injection with 5 mu;l rAAV2-EGFP; The ultrasound irradiation was performed on the rats in group D right after intravitreal injection with the mixture solution of microbubbles and rAAV2-EGFP ultrasound. After 21 days, RGC were labeled retogradely with fluogold. Seven days after labeling, the retinal flatmounts and frozen sections were made from five rats in each group. Expression of EGFP reporter gene was observed by laser scanning confocal microscope and evaluated via average optical intensity (AOD) and RGC transfection rate. Labeled RGC were counted to evaluate the adverse effects.Results Green fluorescence can be observed exactly in labeled RGC in B,C,and D groups. The AOD and transfection rate in group D was (95.02plusmn;7.25)% and(20.10plusmn;0.74)% , respectively; which were higher than those in group B and C (F=25.970,25.799;P<0.01). The difference of the number of RGC among the four groups was not significant(F=0.877,P>0.05). Conclusion  Under the condition of low frequency and with certain energy, ultrasoundmediated microbubble destruction can effectively and safely enhance rAAV delivery to RGC in rats.

    Release date:2016-09-02 05:41 Export PDF Favorites Scan
  • Efficacy of Treatment on Liver Metastases by Contrast Enhanced Ultrasonography-Guided Percutaneous Radiofrequency Ablation

    ObjectiveTo evaluate the clinical application and the efficacy of contrast enhanced ultrasonography (CEUS)guided percutaneous radiofrequency ablation (RFA) in patients with liver metastases. MethodsTotal 136 patients with 219 liver metastatic tumors, which were detected by CEUS before RFA therapy, were analyzed retrospectively. The diamter of tumors was (3.2±1.2) cm. Among them, the largest tumor more than 3 cm in diameter were found in 48.5% (66 patients), and 57.4% (78 patients) were with solitary metastasis. Enhanced CT and (or) MRI, and laboratory tests were applied to evaluate the outcomes after RFA treatment by regular followup. ResultsTumors were not detected by conventional ultrasonography in two cases, and 47.0% (63/134) of the patients with the largest tumor were 0.3 cm larger by CEUS than by conventional ultrasonography. More 40 tumors were detected in 18.4% (25/136) patients by CEUS. Followup ranged from 3 to 68 months (median time of 12 months). Early tumor necrosis rate one month after therapy was 98.2% (215/219 tumors). The incidence of local recurrence, new intrahepatic metastasis, and extrahepatic metastasis was 16.9% (23/136), 38.2% (52/136), and 8.8% (12/136), respectively. Local recurrence and new intrahepatic metastasis happened 2-25 months (median time of 6 months) after treatment. Local recurrence rates of the largest tumors ≥ 3 cm and tumor lt; 3 cm was 22.7% and 11.4%, respectively (P=0.079). The rate of new intrahepatic metastasis for the solitary metastasis cases was significantly lower than that for multiple metastases cases (25.6% versus 55.2%, P=0.000). The 1, 2, 3year survival rates were 82.5%, 64.3%, and 50.1%, and the 1, 2, 3year local recurrence free survival rates were 67.7%, 53.8%, and 38.3%, respetively. Patients with solitary metastasis survived longer than that with multiple metastases (P=0.034). ConclusionPatients with liver metastases treated by CEUSguided percutaneous RFA can get better survival rate, and CEUS is of much value for clinic application.

    Release date:2016-09-08 10:40 Export PDF Favorites Scan
  • Value of Gd-BOPTA Enhanced MR in Diagnosing Hepatocellular Carcinoma with Correlation of Pathology

    Objective To investigate the value of new double-phasic MR contrast agent (gadobenate dimeglumine, Gd-BOPTA) in diagnosis of hepatocellular carcinoma (HCC) with correlation of pathology. Methods MRI scan was performed on 33 patients suspected of having focal liver lesions by CT or ultrasonography. The MRI scan protocol included routine axial T1WI and T2WI, coronal T2WI and 3D-MRCP, Gd-BOPTA enhanced 3D gradient-echo sequence of T1W (LAVA sequence) acquiring dynamic data at 15 s, 55 s and 90 s respectively, delayed LAVA acquisition at 5 min, 10 min, and at 40 min, 80 min respectively. Surgical specimen was collected for pathological analysis.  Results Surgery confirmed the diagnosis of HCC in 21 patients with 27 lesions. The sensitivity, specificity and accuracy of MR imaging with combined phases (including hemodynamic phase and hepatobiliary phase) were 92.9%,93.3%, 92.9% respectively. ①In the hemodynamic phase: 22 lesions showed early enhancement in arterial phase, fast “washout” in portal venous phase, and hypointense in delayed phase. Four lesions showed slight enhancement, while 1 lesion showed no enhancement in all hemodynamic phases. ②In the hepatobiliary phase: 23 lesions showed homogeneous hypointensity compared to the enhanced liver background, but 4 lesions (3 well-differentiated and 1 moderately-differentiated) had patchy or dot-like slightly hyperintense areas scattered within the lesions. Pathologically cholestatic changes of tumor cells were observed and bile-containing small ducts were present. Conclusion Gd-BOPTA enhanced MRI can both depict the hemodynamic characteristics and reflect the absence of normal hepatocyte function in HCC lesions, thus contributing greatly to the diagnosis of HCC.

    Release date:2016-09-08 11:49 Export PDF Favorites Scan
  • 纳米级超声造影剂的技术进展

    纳米级超声造影剂是指直径<1 000 nm的超声造影剂。与微米级微泡相比,纳米造影剂粒径较小,渗透能力极强,可以通过血管内皮间隙,进行病变部位血管外显影。同时因为纳米系统具有一定的靶向能力,将纳米级造影系统与临床治疗相结合可以在肿瘤治疗方面表现出其特定的靶向治疗优势。现就纳米级超声造影剂的特征、国内外制备方法及研究前景进行总结。

    Release date:2016-09-08 09:12 Export PDF Favorites Scan
  • Value of Gd-BOPTA Enhanced MR Imaging in Diagnosing Focal Nodular Hyperplasia of Liver (Report of 5 Cases)

    Objective To investigate the value of a new double action MR contrast agent——Gd-BOPTA in the diagnosis of focal nodular hyperplasia (FNH) of the liver with correlation of pathology. Methods Dedicated MRI scans were performed for 5 patients suspected to have liver FNH on clinical and imaging basis (six lesions). The MR imaging protocol included axial T1W and T2W plain scan, coronal T2 weighted imaging, 3D MRCP, Gd-BOPTA enhanced LAVA dynamic tri-phasic acquisitions (scanning at 15 s, 55 s and 90 s respectively), enhanced 2D T1W scan, enhanced LAVA in delay phase (at 5 and 10 min) and in the hepatobiliary phase (at 40 and 80 min). The imaging features on each MR sequence were compared with surgical and pathological findings. Results Six lesions in 5 FNH patients were all correctly diagnosed (5 conformed by surgery and 1 by needle biopsy). ①The hemodynamic phase: The parenchyma of 5 lesions were markedly enhanced in the arterial phase, being isointense or slight hypointense in both the portal venous and delay phases, while 1 lesion was isointense in all phases except being slight hyperintense in the arterial phase; The central scar of 5 lesions were not enhanced in the dynamic phase, but showed delayed enhancement. ②The hepatobiliary (excretory) phase: The parenchyma of all 6 lesions were slight hyperintense or isointense, and tree-like bile ducts with hyperintensity were seen within one lesion. The scar showed no enhancement. ③Pathology: The parenchyma was consisted of disarranged normal hepatocytes but with cytoedema, lack of portal tracts and cholestatic change. The central scar showed rich fibrous tissue, a very thick-walled arteriole, proliferative bile ducts, infiltration of inflammatory cells and myxomatous changes. Conclusion As a dual-phase MR contrast agent capable of depicting both the hemodynamic attributes and hepatobiliary excretion, Gd-BOPTA enhanced MRI can reflect the pathological features of FNH and reach a high diagnostic accuracy.

    Release date:2016-09-08 11:49 Export PDF Favorites Scan
  • Clinical Character of Contrastinduced Nephropathy in Patients with Diabetes

    目的:观察糖尿病患者使用造影剂后发生造影剂肾病的临床情况。方法:108例肾功能正常的患者根据血糖水平被分为3组,分别接受X线造影,观察3组发生造影剂肾病情况。结果: 血糖正常组血清肌酐造影前后无明显变化,糖尿病早期组造影后血肌酐升高,与造影前相比有统计学意义(Plt;005),糖尿病组造影后肌酐升高明显,与造影前相比具有显著统计学意义(Plt;001),且血肌酐恢复较慢,造影后第5天仍处于较高水平,与造影前相比有统计学意义(Plt;005)。结论: 糖尿病早期及糖尿病患者即使肾功能正常,使用造影剂后也容易发生造影剂肾病,对这类高危人群应尽量避免使用造影剂。

    Release date:2016-08-26 02:21 Export PDF Favorites Scan
  • Magnetic Resonance Imaging Evaluation of The Gallbladder

    胆囊作为贮存和浓缩胆汁的器官,其内的胆汁易于析出、凝集而形成结石。胆囊最常见的疾病多与结石相关,如胆石症、急慢性胆囊炎、胆囊癌等; 其他影响胆囊的病理状态还包括胆道动力障碍、术后改变等。超声对胆囊结石及胆囊炎的诊断有较高的敏感性及特异性,还可通过摄取高脂食物前后对比评价胆囊功能,是胆囊疾病的传统影像检查手段,但对肥胖患者其图像质量及解剖细节显示较差。目前,常规MRI已经成为重要的胆囊成像方法之一,并可引入经胆道排泄的造影剂进一步清晰显示其解剖及生理。对于超声不能很好评价的胆囊疾病患者应首选MRI检查。

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  • Protection of retinal ganglion cells from optic nerve injury by brainderived neurotrophic factor transfected through microbubble contrast agent into the retina and visual cortex

      Objective To observe the protective effect of ultrasound microbubble contrast agentmediated transfection of brain-derived neurotrophic factor(BDNF) into the retina and visual cortex on retinal ganglion cells (RGC) after optic nerve injury. Methods A total of 88 male Sprague-Dawley (SD) rats were randomly divided into normal group (group A, eight rats), sham operation group (group B, 16 rats), control group (group C, 16 rats), eyes transfection group (group D, 16 rats), brain transfection group (group E, 16 rats), combined transfection group (group F, 16 rats). The optic nerve crush injury was induced, and then the groups B to F were divided into one-week and two-week after optic nerve injury subgroup with eight rats each, respectively. The rats in group B and C underwent intravitreal and visual cortex injection with phosphate buffered solution respectively. The rats in group D and E underwent intravitreal and visual cortex injection with the mixture solution of microbubbles and BDNF plasmids respectively. The rats in group F underwent both intravitreal and visual cortex injection with the mixture solution of microbubbles and BDNF plasmids at the same time. The ultrasound exposure was performed on the rats in group D to F after injection with the mixture solution of microbubbles and BDNF plasmids. One and two weeks after optic nerve injury, RGC were retrogradely labeled with Fluorogold; active caspase-3 protein was observed by immunohistochemistry and the N95 amplitude was detected by pattern electroretinogram (PERG). Results Golden fluorescence can be observed exactly in labeled RGC in all groups,the difference of the number of RGC between the six groups and ten subgroups were significant(F=256.30,65.18;P<0.01). Active caspase-3 in ganglion cell layer was detected in group C to F, but not in group A and B. The difference of the N95 amplitude between the six groups and ten subgroups were significant(F=121.56,82.38;P<0.01).Conclusion Ultrasound microbubble contrast agent-mediated BDNF transfection to the rat retina and visual cortex can inhibit the RGC apoptosis after optic nerve injury and protect the visual function.

    Release date:2016-09-02 05:37 Export PDF Favorites Scan
  • Study of Portal Vein Tumor Thrombus and Portal Vein Thrombosis with Contrast-Enhanced Ultrasonograph

    目的 探讨超声造影对门静脉癌栓和血栓的鉴别诊断价值。方法 应用超声造影剂(SonoVue)对16例门静脉癌栓及8例门静脉血栓行实时低机械指数超声造影,观察并分析其造影增强特征。 结果 16例癌栓超声造影动脉相10例呈整体均匀性增强,2例呈整体不均匀性增强,2例呈整体轻度增强,2例栓子一部分增强,另一部分无增强; 门脉相特别是门脉相晚期和延迟相14例栓子呈充盈缺损状态,2例栓子仍呈轻微强化。4例常规彩超检查未能检出动脉血流信号而不能确诊的癌栓,超声造影均显示其动脉相增强。8例血栓行超声造影后整个造影过程栓子均未见增强。结论 超声造影可敏感地反映门静脉栓子的血流灌注,门静脉癌栓和血栓在超声造影后有显著的特征,有助于两者的鉴别诊断。

    Release date:2016-09-08 11:07 Export PDF Favorites Scan
  • Method for Extracting Vascular Perfusion Region Based on Ultrasound Contrast Agent

    Vascular perfusion distribution in fibroids contrast-enhanced ultrasound images provides useful pathological and physiological information, because the extraction of the vascular perfusion area can be helpful to quantitative evaluation of uterine fibroids blood supply. The pixel gray scale in vascular perfusion area of fibroids contrast-enhanced ultrasound image sequences is different from that in other regions, and, based on this, we proposed a method of extracting vascular perfusion area of fibroids. Firstly, we denoised the image sequence, and then we used Brox optical flow method to estimate motion of two adjacent frames, based on the results of the displacement field for motion correction. Finally, we extracted vascular perfusion region from the surrounding background based on the differences in gray scale for the magnitude of the rich blood supply area and lack of blood supply area in ultrasound images sequence. The experimental results showed that the algorithm could accurately extract the vascular perfusion area, reach the precision of identification of clinical perfusion area, and only small amount of calculation was needed and the process was fairly simple.

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