Steam flooding with the assistance of carbon dioxide (CO_(2)) and chemicals is an effective approach for enhancing super heavy oil recovery. However, the promotion and application of CO_(2) and chemical agent-assisted...Steam flooding with the assistance of carbon dioxide (CO_(2)) and chemicals is an effective approach for enhancing super heavy oil recovery. However, the promotion and application of CO_(2) and chemical agent-assisted steam flooding technology have been restricted by the current lack of research on the synergistic effect of CO_(2) and chemical agents on enhanced steam flooding heat transfer. The novel experiments on CO_(2)–chemicals cooperate affected steam condensation and seepage were conducted by adding CO_(2) and two chemicals (sodium dodecyl sulfate (SDS) and the betaine temperature-salt resistant foaming agent ZK-05200).According to the experimental findings, a “film” formed on the heat-transfer medium surface following the co-injection of CO_(2) and the chemical to impede the steam heat transfer, reducing the heat transfer efficiency of steam, heat flux and condensation heat transfer coefficient. The steam seepage experiment revealed that the temperature at the back end of the sandpack model was dramatically raised by 3.5–12.8 °C by adding CO_(2) and chemical agents, achieving the goal of driving deep-formation heavy oil. The combined effect of CO_(2) and SDS was the most effective for improving steam heat transfer, the steam heat loss was reduced by 6.2%, the steam condensation cycle was prolonged by 1.3 times, the condensation heat transfer coefficient was decreased by 15.5%, and the heavy oil recovery was enhanced by 9.82%. Theoretical recommendations are offered in this study for improving the CO_(2)–chemical-assisted steam flooding technique.展开更多
This study used the diethylene triamine pentaacetic acid(DTPA)-seawater(SW)system to modify the sandstone rock wettability and enhance oil recovery.The investigation involved conducting wettability measurement,Zeta po...This study used the diethylene triamine pentaacetic acid(DTPA)-seawater(SW)system to modify the sandstone rock wettability and enhance oil recovery.The investigation involved conducting wettability measurement,Zeta potential measurement,and spontaneous imbibition experiment.The introduction of 5%DTPA-sW solution resulted in a significant decrease in the rock-oil contact angle from 143°to 23,along with a reduction in the Zeta potential from-2.29 mV to-13.06 mV,thereby altering the rock surface charge and shifting its wettability from an oil-wet state to a strongly water-wet state.The presence or absence of potential determining ions(Ca^(2+),Mg^(2+),SO_(4)^(2-))in the solution did not impact the effectiveness of DTPA in changing the rock wettability.However,by tripling the concentration of these ions in the solution,the performance of 5%DTPA-SW solution in changing wettability was impaired.Additionally,spontaneous imbibition tests demonstrated that the 5%DTPA-SW solution led to an increase in oil recovery up to 39.6%.Thus,the optimum mass fraction of DTPA for changing sandstone wettability was determined to be5%.展开更多
Hepatocellular carcinoma(HCC)is the sixth most common neoplasm and the third cause of cancer death worldwide.Contrast enhanced ultrasound(CEUS)has been applied for more than ten years and plays increasingly important ...Hepatocellular carcinoma(HCC)is the sixth most common neoplasm and the third cause of cancer death worldwide.Contrast enhanced ultrasound(CEUS)has been applied for more than ten years and plays increasingly important roles in the management of HCC.On the basis of the Guideline and Good Clinical Practice Recommendations for CEUS in the liver-update 2012and related literature about the management of HCC,we summarize the main roles and applications of CEUS in the management of HCC,including HCC surveillance,diagnosis,CEUS-guided treatment,treatment response evaluation and follow-up.The diagnostic algorithm for HCC is also suggested.Meanwhile,the comparisons between CEUS and contrast enhanced computed tomography/magnetic resonance imaging(CECT/CEMRI)in these areas are made.Although CEUS is subject to the same limitation as ordinary US and is inferior to CECT/CEMRI in some aspects,CEUS has proved to be of great value in the management of HCC with inher-ent advantages,such as sufficient high safety profile making it suitable for patients with renal failure or allergic to iodine,absence of radiation,easy reproducibility and high temporal resolution.The tremendous application of CEUS to the diagnosis and treatment of HCC provides more opportunities for patients with HCC diagnosed at different stages.展开更多
Liver transplantation is an effective treatment for patients with end-stage liver disease. Accurate imaging evaluation of the transplanted patient is critical for ensuring that the limited donor liver is functioning a...Liver transplantation is an effective treatment for patients with end-stage liver disease. Accurate imaging evaluation of the transplanted patient is critical for ensuring that the limited donor liver is functioning appropriately. Ultrasound contrast agents(UCAs), in combination with contrastspecific imaging techniques, are increasingly accepted in clinical use for the assessment of the hepatic vasculature, bile ducts and liver parenchyma in pre-, intra- and posttransplant patients. We describe UCAs, their technical requirements, the recommended clinical indications, image interpretation and the limitations for contrastenhanced ultrasound applications in liver transplantation.展开更多
AIM:To verify whether arterial-phase contrast-enhanced ultrasonography(CEUS) of tumor parenchymal tissue is useful for evaluation of anti-angiogenesis agents.METHODS:Rabbits with liver tumor were subjected to CEUS,and...AIM:To verify whether arterial-phase contrast-enhanced ultrasonography(CEUS) of tumor parenchymal tissue is useful for evaluation of anti-angiogenesis agents.METHODS:Rabbits with liver tumor were subjected to CEUS,and images of the nodular maximal diameter in vascular phase were recorded.Image analysis was performed to plot the time intensity curve(TIC) at the tumor parenchyma,which set the diameter of the region of interest of intensity measurement.The TIC was calculated to obtain the time to peak intensity(TPI) and the magnitude of PI.Rabbits were randomly assigned to a treatment group with sorafenib and a control group.Two weeks later,the same ultrasound examination was repeated followed by pathological testing to assess the effect of sorafenib on the liver tumor.RESULTS:In four rabbits in the treatment group,the rate of change of tumor size was decreased comparedwith that of the control(the rate 2.3 vs 7.9,P = 0.02).The TPI of the treatment group elongated significantly(the rate 3.1 vs 1.1,P = 0.07 for SonoVue,2.0 vs 0.88,P = 0.09 for Sonazoid).The magnitude of PI showed no significant changes.In pathological examination,capillary diameters in the treatment group were significantly smaller than those in the control group(26.4 vs 42.8 μm,P = 0.013).CONCLUSION:Analysis of the TIC in the arterial phase of tumor tissue could evaluate the efficacy of antiangiogenesis drug treatment in liver tumor.展开更多
Over the last decade, the development of stabilised microbubble contrast agents and improvements in available ultrasonic equipment, such as harmonic imaging, have enabled us to display microbubble enhancements on a gr...Over the last decade, the development of stabilised microbubble contrast agents and improvements in available ultrasonic equipment, such as harmonic imaging, have enabled us to display microbubble enhancements on a greyscale with optimal contrast and spatial resolution. Recent technological advances made contrast harmonic technology available for endoscopic ultrasound(EUS) for the first time in 2008. Thus, the evaluation of microcirculation is now feasible with EUS, prompting the evolution of contrast-enhanced EUS from vascular imaging to images of the perfused tissue. Although the relevant experience is still preliminary, several reports have highlighted contrast-enhanced harmonic EUS(CHEUS) as a promising noninvasive method to visualise and characterise lesions and to differentiate benign from malignant focal lesions. Even if histology remains the gold standard, the combination of CH-EUS and EUS fine needle aspiration(EUS-FNA) can not only render EUS more accurate but may also assist physicians inmaking decisions when EUS-FNA is inconclusive,increasing the yield of EUS-FNA by guiding the puncture with simultaneous imaging of the vascularity.The development of CH-EUS has also opened up exciting possibilities in other research areas,including monitoring responses to anticancer chemotherapy or to ethanolinduced pancreatic tissue ablation,anticancer therapies based on ultrasound-triggered drug and gene delivery,and therapeutic adjuvants by contrast ultrasound-induced apoptosis.Contrast harmonic imaging is gaining popularity because of its efficacy,simplicity and noninvasive nature,and many expectations are currently resting on this technique.If its potential is confirmed in the near future,contrast harmonic imaging will become a standard practice in EUS.展开更多
To explore the clinical value of contrast-enhanced ultrasound (CEUS) in differentiating benign and malignant focal liver lesions (FLLs) with SonoVue, CEUS was used to examine 113 patients with focal liver lesions ...To explore the clinical value of contrast-enhanced ultrasound (CEUS) in differentiating benign and malignant focal liver lesions (FLLs) with SonoVue, CEUS was used to examine 113 patients with focal liver lesions (FLLs) in our hospital during July 2005 to December 2006. All the patients underwent contrast-enhanced CT (CECT) or contrast-enhanced MRI (CEMRI). Except for patients with focal fatty sparings (n=18) and with hemangiomas (n=8), all the patients were confirmed by operation or ultrasonic-guided liver puncture biopsy. A sulfur hexafluoride gas-based contrast agent was used with a MI of 0.15 to 0.17. Forty-eight cases of malignant FLLs, including 30 hepatocellular carcinomas (HCCs), 2 cholangiocarcinomas and 16 metastatic tumors, were detected. Seventy-eight cases of benign FLLs, including 33 hemangiomas, 9 focal nodular hyperplasias (FNHs), 19 focal fatty sparings, 5 abscesses, 7 regenerative nodules and 2 inflammatory pseudo-tumor, were involved. The contrast pattern of benign and malignant FLLs was quite different. CEUS has higher specificity and sensitivity than conventional ultrasound in differentiating benign and malignant FLLs.展开更多
The development of ultrasound contrast agents with excellent tolerance and safety profiles has notably improved liver evaluation with ultrasound(US)for several applications,especially for the detection of metastases.I...The development of ultrasound contrast agents with excellent tolerance and safety profiles has notably improved liver evaluation with ultrasound(US)for several applications,especially for the detection of metastases.In particular,contrast enhanced ultrasonography(CEUS)allows the display of the parenchymal microvasculature,enabling the study and visualization of the enhancement patterns of liver lesions in real time and in a continuous manner in all vascular phases,which is similar to contrast-enhanced computed tomography(CT)and contrast-enhanced magnetic resonance imaging.Clinical studies have reported that the use of a contrast agent enables the visualization of more metastases with significantly improved sensitivity and specificity compared to baseline-US.Furthermore,studies have shown that CEUS yields sensitivities comparable to CT.In this review,we describe the state of the art of CEUS for detecting colorectal liver metastases,the imaging features,the literature reports of metastases in CEUS as well as its technique,its clinical role and its potential applications.Additionally,the updated international consensus panel guidelines are reported in this review with the inherent limitations of this technique and best practice experiences.展开更多
Objective: To explore application of targeted contrast enhanced ultrasonography in diagnosis of early stage vascular endothelial injury and diabetic nephropathy. Methods: Targeted Sono VueTM microbubble was prepared b...Objective: To explore application of targeted contrast enhanced ultrasonography in diagnosis of early stage vascular endothelial injury and diabetic nephropathy. Methods: Targeted Sono VueTM microbubble was prepared by attaching anti-TM monoclonal antibody to the surface of ordinary micro-bubble Sono Vue by biotin-avidin bridge method and ultrasonic instrument was used to evaluate the developing situation of targeted microbubble in vitro. Twenty 12-week-old male GK rats and 20 Wistar rats were enrolled in this study, and were randomly divided into targeted angiography group and ordinary angiography group. Targeted microbubbles Sono VueTM or general microbubble Sono Vue were rapidly injected to the rats via tail vein; the developing situation of the two contrast agents in rats kidneys was dynamically observed. Time intensity curve was used to analyse rat kidney perfusion characteristics in different groups. Results: Targeted ultrasound microbubble Sono Vue-TM was successfully constructed, and it could be used to develop an external image. Targeted microbubbles Sono Vue-TM enabled clear development of experimental rat kidney. Time intensity curve shapes of rat kidney of the two groups showed as single apex with steep ascending and slowly descending branch. Compared with the control group, the rising slope of the GK rat renal cortex, medulla in targeted angiography group increased(P<0.05); the peak intensity of medulla increased(P<0.05), and the total area under the curve of medulla increased(P<0.05). Compared with control group, the ascending branch of the GK rat in renal cortex, medulla in ordinary angiography group increased(P<0.05). The peak intensity of the curve increased(P<0.05), and the total area under the curve increased(P<0.05). Compared with the ordinary angiography group, the peak of GK rat medullacurve in targeted angiography group intensity increased(P<0.05), and the total area under the curve increased(P<0.05). Conclusions: Targeted microbubbles Sono VueTM can make a clear development of experimental rat kidney, its stable performance meet the requirement of ultrasonic observation time limit, and it can reflect early changes of blood perfusion in GK rat kindey.展开更多
BACKGROUND: Studies have demonstrated that ultrasound-mediated microbubble destruction significantly improves transfection efficiency of enhanced green fluorescent protein (EGFP) in in vitro cultured retinal gangli...BACKGROUND: Studies have demonstrated that ultrasound-mediated microbubble destruction significantly improves transfection efficiency of enhanced green fluorescent protein (EGFP) in in vitro cultured retinal ganglial cells (RGCs). OBJECTIVE: To investigate the feasibility of ultrasound-mediated microbubble destruction for EGFP transfection in rat RGCs, and to compare efficiency and cell damage with traditional transfection methods. DESIGN, TIME AND SETTING: In vivo, gene engineering experiment. The study was performed at the Central Laboratory, Institute of Ultrasonic Imaging, Chongqing Medical University from March to July 2008. MATERIALS: Eukaryotic expression vector plasmid EGFP and microbubbles were prepared by the Institute of Ultrasonic Imaging, Chongqing Medical University. The microbubbles were produced at a concentration of 8.7 × 10^11/L, with a 2-4 μm diameter, and 10-hour half-life in vitro. METHODS: A total of 50 Sprague Dawley rats were randomly assigned to four groups. Normal controls (n = 5) were infused with 5 μL normal saline to the vitreous cavity; the naked plasmid group (n = 15) was infused with 5 pL EGFP plasmid to the vitreous cavity; in the plasmid with ultrasound group (n = 15), the eyes were irradiated with low-energy ultrasound wave (0.5 W/cm^2) for a total of 60 seconds (irradiated for 5 seconds, at 10-second intervals) immediately following infusion of EGFP plasmids to the vitreous cavities. In the microbubble-ultrasound group (n = 15), the eyes were irradiated with the same power of ultrasonic wave immediately following infusion of microbubbles containing EGFP plasmids to the vitreous cavities. MAIN OUTCOME MEASURES: After 7 days, retinal preparations and EGFP expression in RGCs were observed by fluorescence microscopy. RGC quantification in the retinal ganglion cell layer was performed. In addition, EGFP mRNA expression was semi-quantitatively determined by RT-PCR. RESULTS: The transfection efficiency of EGFP to RGCs by microbubbles with ultrasound was significantly greater than the other groups, and no obvious damage was detected in the RGCs. CONCLUSION: Under irradiation of low-frequency ultrasound waves, ultrasound-mediated microbubble destruction was effective and resulted in safe transfection of the EGFP gene to the RGCs.展开更多
Contrast enhanced ultrasonography(CEUS) has improved both the detection and characterization of foca liver lesions.It is now possible to evaluate in real time the perfusion of focal liver lesions in the arterial,porta...Contrast enhanced ultrasonography(CEUS) has improved both the detection and characterization of foca liver lesions.It is now possible to evaluate in real time the perfusion of focal liver lesions in the arterial,porta and late contrast phases,and thus to characterize focal liver lesions with high diagnostic accuracy.As a result,CEUS has taken a central diagnostic role in the evaluation of focal liver lesions that are indeterminate upon computed tomography(CT) and magnetic resonance imaging.The combined use of second generation contrast agents and low mechanica index techniques is essential for the detection of liver metastases,and it now allows the examination of the entire liver in both the portal and late phases. Several studies have shown that using CEUS instead of conventional ultrasonography without contrast agents significantly improves sensitivity in detection of liver metastases.Furthermore,the detection rate with CEUS seems to be similar to that of CT.This review describes the clinical role of CEUS in detecting liver metastases,including details about examination techniques,features of metastases observed with CEUS,and clinical results and guidelines.展开更多
AIM To perform a meta-analysis assessing the value of gadoxetic acid-enhanced magnetic resonance imaging(Gd-EOB-MRI)in detecting small hepatocellular carcinoma(HCC)(≤2.0 cm)in patients with chronic liver disease.METH...AIM To perform a meta-analysis assessing the value of gadoxetic acid-enhanced magnetic resonance imaging(Gd-EOB-MRI)in detecting small hepatocellular carcinoma(HCC)(≤2.0 cm)in patients with chronic liver disease.METHODS Databases,including MEDLINE and EMBASE,were searched for relevant original articles published from January 2008 to February 2015.Data were extracted,and summary estimates of diagnostic accuracy indexes such as sensitivity,specificity,diagnostic odds ratio,predictive value,and areas under summary receiver operating characteristic curve were obtained using a random-effects model,with further exploration employing meta-regression and subgroup analyses.RESULTS In 10 studies evaluating 768 patients,pooled perlesion sensitivity of Gd-EOB-DTPA was 91%(95%CI:83%-95%),with a specificity of 95%(95%CI:87%-98%).Overall positive likelihood ratio was 18.1(95%CI:6.6-49.4),for negative likelihood ratio(NLR)of 0.10(95%CI:0.05-0.19)and diagnostic odds ratio of182(95%CI:57-581).Subgroup analysis suggested that diagnostic performance of Gd-EOB-MRI for sub-centimeter HCC(≤1.0 cm)detection was low,with a sensitivity of69%(95%CI:59%-78%).In studies with both Gd-EOBMRI and diffusion-weighted imaging(DWI)performed,Gd-EOB-MRI/DWI combination was more sensitive than Gd-EOB-DTPA alone,whether for small lesions(86%vs77%)or sub-centimeter ones(80%vs 56%).CONCLUSION A limited number of small studies suggested that GdEOB-MRI has good diagnostic performance in the detection of small HCC(≤2.0 cm)among patients with chronic liver disease,but relatively lower performance for detection of sub-centimeter HCC(≤1.0 cm).Combination of Gd-EOB-MRI and DWI can improve the diagnostic sensitivity of MRI.展开更多
基金financial support of the National Nature Science Foundation of China(Grant No.U20B6003)the Natural Science Foundation of Shandong Province,China(ZR2020QE106).
文摘Steam flooding with the assistance of carbon dioxide (CO_(2)) and chemicals is an effective approach for enhancing super heavy oil recovery. However, the promotion and application of CO_(2) and chemical agent-assisted steam flooding technology have been restricted by the current lack of research on the synergistic effect of CO_(2) and chemical agents on enhanced steam flooding heat transfer. The novel experiments on CO_(2)–chemicals cooperate affected steam condensation and seepage were conducted by adding CO_(2) and two chemicals (sodium dodecyl sulfate (SDS) and the betaine temperature-salt resistant foaming agent ZK-05200).According to the experimental findings, a “film” formed on the heat-transfer medium surface following the co-injection of CO_(2) and the chemical to impede the steam heat transfer, reducing the heat transfer efficiency of steam, heat flux and condensation heat transfer coefficient. The steam seepage experiment revealed that the temperature at the back end of the sandpack model was dramatically raised by 3.5–12.8 °C by adding CO_(2) and chemical agents, achieving the goal of driving deep-formation heavy oil. The combined effect of CO_(2) and SDS was the most effective for improving steam heat transfer, the steam heat loss was reduced by 6.2%, the steam condensation cycle was prolonged by 1.3 times, the condensation heat transfer coefficient was decreased by 15.5%, and the heavy oil recovery was enhanced by 9.82%. Theoretical recommendations are offered in this study for improving the CO_(2)–chemical-assisted steam flooding technique.
文摘This study used the diethylene triamine pentaacetic acid(DTPA)-seawater(SW)system to modify the sandstone rock wettability and enhance oil recovery.The investigation involved conducting wettability measurement,Zeta potential measurement,and spontaneous imbibition experiment.The introduction of 5%DTPA-sW solution resulted in a significant decrease in the rock-oil contact angle from 143°to 23,along with a reduction in the Zeta potential from-2.29 mV to-13.06 mV,thereby altering the rock surface charge and shifting its wettability from an oil-wet state to a strongly water-wet state.The presence or absence of potential determining ions(Ca^(2+),Mg^(2+),SO_(4)^(2-))in the solution did not impact the effectiveness of DTPA in changing the rock wettability.However,by tripling the concentration of these ions in the solution,the performance of 5%DTPA-SW solution in changing wettability was impaired.Additionally,spontaneous imbibition tests demonstrated that the 5%DTPA-SW solution led to an increase in oil recovery up to 39.6%.Thus,the optimum mass fraction of DTPA for changing sandstone wettability was determined to be5%.
基金Supported by National Natural Science Foundation of China,Nos.81371570,81301229 and 81301299Key Project from Shanghai Health Bureau,No.20114003Shanghai Talent Development Project from Shanghai Human Resource and Social Security Bureau,No.2012045
文摘Hepatocellular carcinoma(HCC)is the sixth most common neoplasm and the third cause of cancer death worldwide.Contrast enhanced ultrasound(CEUS)has been applied for more than ten years and plays increasingly important roles in the management of HCC.On the basis of the Guideline and Good Clinical Practice Recommendations for CEUS in the liver-update 2012and related literature about the management of HCC,we summarize the main roles and applications of CEUS in the management of HCC,including HCC surveillance,diagnosis,CEUS-guided treatment,treatment response evaluation and follow-up.The diagnostic algorithm for HCC is also suggested.Meanwhile,the comparisons between CEUS and contrast enhanced computed tomography/magnetic resonance imaging(CECT/CEMRI)in these areas are made.Although CEUS is subject to the same limitation as ordinary US and is inferior to CECT/CEMRI in some aspects,CEUS has proved to be of great value in the management of HCC with inher-ent advantages,such as sufficient high safety profile making it suitable for patients with renal failure or allergic to iodine,absence of radiation,easy reproducibility and high temporal resolution.The tremendous application of CEUS to the diagnosis and treatment of HCC provides more opportunities for patients with HCC diagnosed at different stages.
基金Supported by National Natural Science Foundation of ChinaNo.81371554+1 种基金Science and Technology Planning Project of Guangdong Province of ChinaNo.2013B021800092
文摘Liver transplantation is an effective treatment for patients with end-stage liver disease. Accurate imaging evaluation of the transplanted patient is critical for ensuring that the limited donor liver is functioning appropriately. Ultrasound contrast agents(UCAs), in combination with contrastspecific imaging techniques, are increasingly accepted in clinical use for the assessment of the hepatic vasculature, bile ducts and liver parenchyma in pre-, intra- and posttransplant patients. We describe UCAs, their technical requirements, the recommended clinical indications, image interpretation and the limitations for contrastenhanced ultrasound applications in liver transplantation.
文摘AIM:To verify whether arterial-phase contrast-enhanced ultrasonography(CEUS) of tumor parenchymal tissue is useful for evaluation of anti-angiogenesis agents.METHODS:Rabbits with liver tumor were subjected to CEUS,and images of the nodular maximal diameter in vascular phase were recorded.Image analysis was performed to plot the time intensity curve(TIC) at the tumor parenchyma,which set the diameter of the region of interest of intensity measurement.The TIC was calculated to obtain the time to peak intensity(TPI) and the magnitude of PI.Rabbits were randomly assigned to a treatment group with sorafenib and a control group.Two weeks later,the same ultrasound examination was repeated followed by pathological testing to assess the effect of sorafenib on the liver tumor.RESULTS:In four rabbits in the treatment group,the rate of change of tumor size was decreased comparedwith that of the control(the rate 2.3 vs 7.9,P = 0.02).The TPI of the treatment group elongated significantly(the rate 3.1 vs 1.1,P = 0.07 for SonoVue,2.0 vs 0.88,P = 0.09 for Sonazoid).The magnitude of PI showed no significant changes.In pathological examination,capillary diameters in the treatment group were significantly smaller than those in the control group(26.4 vs 42.8 μm,P = 0.013).CONCLUSION:Analysis of the TIC in the arterial phase of tumor tissue could evaluate the efficacy of antiangiogenesis drug treatment in liver tumor.
文摘Over the last decade, the development of stabilised microbubble contrast agents and improvements in available ultrasonic equipment, such as harmonic imaging, have enabled us to display microbubble enhancements on a greyscale with optimal contrast and spatial resolution. Recent technological advances made contrast harmonic technology available for endoscopic ultrasound(EUS) for the first time in 2008. Thus, the evaluation of microcirculation is now feasible with EUS, prompting the evolution of contrast-enhanced EUS from vascular imaging to images of the perfused tissue. Although the relevant experience is still preliminary, several reports have highlighted contrast-enhanced harmonic EUS(CHEUS) as a promising noninvasive method to visualise and characterise lesions and to differentiate benign from malignant focal lesions. Even if histology remains the gold standard, the combination of CH-EUS and EUS fine needle aspiration(EUS-FNA) can not only render EUS more accurate but may also assist physicians inmaking decisions when EUS-FNA is inconclusive,increasing the yield of EUS-FNA by guiding the puncture with simultaneous imaging of the vascularity.The development of CH-EUS has also opened up exciting possibilities in other research areas,including monitoring responses to anticancer chemotherapy or to ethanolinduced pancreatic tissue ablation,anticancer therapies based on ultrasound-triggered drug and gene delivery,and therapeutic adjuvants by contrast ultrasound-induced apoptosis.Contrast harmonic imaging is gaining popularity because of its efficacy,simplicity and noninvasive nature,and many expectations are currently resting on this technique.If its potential is confirmed in the near future,contrast harmonic imaging will become a standard practice in EUS.
基金a key program from the Na-tional Natural Sciences Foundation of China (No. 90209009).
文摘To explore the clinical value of contrast-enhanced ultrasound (CEUS) in differentiating benign and malignant focal liver lesions (FLLs) with SonoVue, CEUS was used to examine 113 patients with focal liver lesions (FLLs) in our hospital during July 2005 to December 2006. All the patients underwent contrast-enhanced CT (CECT) or contrast-enhanced MRI (CEMRI). Except for patients with focal fatty sparings (n=18) and with hemangiomas (n=8), all the patients were confirmed by operation or ultrasonic-guided liver puncture biopsy. A sulfur hexafluoride gas-based contrast agent was used with a MI of 0.15 to 0.17. Forty-eight cases of malignant FLLs, including 30 hepatocellular carcinomas (HCCs), 2 cholangiocarcinomas and 16 metastatic tumors, were detected. Seventy-eight cases of benign FLLs, including 33 hemangiomas, 9 focal nodular hyperplasias (FNHs), 19 focal fatty sparings, 5 abscesses, 7 regenerative nodules and 2 inflammatory pseudo-tumor, were involved. The contrast pattern of benign and malignant FLLs was quite different. CEUS has higher specificity and sensitivity than conventional ultrasound in differentiating benign and malignant FLLs.
文摘The development of ultrasound contrast agents with excellent tolerance and safety profiles has notably improved liver evaluation with ultrasound(US)for several applications,especially for the detection of metastases.In particular,contrast enhanced ultrasonography(CEUS)allows the display of the parenchymal microvasculature,enabling the study and visualization of the enhancement patterns of liver lesions in real time and in a continuous manner in all vascular phases,which is similar to contrast-enhanced computed tomography(CT)and contrast-enhanced magnetic resonance imaging.Clinical studies have reported that the use of a contrast agent enables the visualization of more metastases with significantly improved sensitivity and specificity compared to baseline-US.Furthermore,studies have shown that CEUS yields sensitivities comparable to CT.In this review,we describe the state of the art of CEUS for detecting colorectal liver metastases,the imaging features,the literature reports of metastases in CEUS as well as its technique,its clinical role and its potential applications.Additionally,the updated international consensus panel guidelines are reported in this review with the inherent limitations of this technique and best practice experiences.
基金supported by Shanghai Municipal Commission of Health and Family Health Planning Key Projects(NO.20134023)
文摘Objective: To explore application of targeted contrast enhanced ultrasonography in diagnosis of early stage vascular endothelial injury and diabetic nephropathy. Methods: Targeted Sono VueTM microbubble was prepared by attaching anti-TM monoclonal antibody to the surface of ordinary micro-bubble Sono Vue by biotin-avidin bridge method and ultrasonic instrument was used to evaluate the developing situation of targeted microbubble in vitro. Twenty 12-week-old male GK rats and 20 Wistar rats were enrolled in this study, and were randomly divided into targeted angiography group and ordinary angiography group. Targeted microbubbles Sono VueTM or general microbubble Sono Vue were rapidly injected to the rats via tail vein; the developing situation of the two contrast agents in rats kidneys was dynamically observed. Time intensity curve was used to analyse rat kidney perfusion characteristics in different groups. Results: Targeted ultrasound microbubble Sono Vue-TM was successfully constructed, and it could be used to develop an external image. Targeted microbubbles Sono Vue-TM enabled clear development of experimental rat kidney. Time intensity curve shapes of rat kidney of the two groups showed as single apex with steep ascending and slowly descending branch. Compared with the control group, the rising slope of the GK rat renal cortex, medulla in targeted angiography group increased(P<0.05); the peak intensity of medulla increased(P<0.05), and the total area under the curve of medulla increased(P<0.05). Compared with control group, the ascending branch of the GK rat in renal cortex, medulla in ordinary angiography group increased(P<0.05). The peak intensity of the curve increased(P<0.05), and the total area under the curve increased(P<0.05). Compared with the ordinary angiography group, the peak of GK rat medullacurve in targeted angiography group intensity increased(P<0.05), and the total area under the curve increased(P<0.05). Conclusions: Targeted microbubbles Sono VueTM can make a clear development of experimental rat kidney, its stable performance meet the requirement of ultrasonic observation time limit, and it can reflect early changes of blood perfusion in GK rat kindey.
基金the National Natural Science Foundation of China,No.30430230
文摘BACKGROUND: Studies have demonstrated that ultrasound-mediated microbubble destruction significantly improves transfection efficiency of enhanced green fluorescent protein (EGFP) in in vitro cultured retinal ganglial cells (RGCs). OBJECTIVE: To investigate the feasibility of ultrasound-mediated microbubble destruction for EGFP transfection in rat RGCs, and to compare efficiency and cell damage with traditional transfection methods. DESIGN, TIME AND SETTING: In vivo, gene engineering experiment. The study was performed at the Central Laboratory, Institute of Ultrasonic Imaging, Chongqing Medical University from March to July 2008. MATERIALS: Eukaryotic expression vector plasmid EGFP and microbubbles were prepared by the Institute of Ultrasonic Imaging, Chongqing Medical University. The microbubbles were produced at a concentration of 8.7 × 10^11/L, with a 2-4 μm diameter, and 10-hour half-life in vitro. METHODS: A total of 50 Sprague Dawley rats were randomly assigned to four groups. Normal controls (n = 5) were infused with 5 μL normal saline to the vitreous cavity; the naked plasmid group (n = 15) was infused with 5 pL EGFP plasmid to the vitreous cavity; in the plasmid with ultrasound group (n = 15), the eyes were irradiated with low-energy ultrasound wave (0.5 W/cm^2) for a total of 60 seconds (irradiated for 5 seconds, at 10-second intervals) immediately following infusion of EGFP plasmids to the vitreous cavities. In the microbubble-ultrasound group (n = 15), the eyes were irradiated with the same power of ultrasonic wave immediately following infusion of microbubbles containing EGFP plasmids to the vitreous cavities. MAIN OUTCOME MEASURES: After 7 days, retinal preparations and EGFP expression in RGCs were observed by fluorescence microscopy. RGC quantification in the retinal ganglion cell layer was performed. In addition, EGFP mRNA expression was semi-quantitatively determined by RT-PCR. RESULTS: The transfection efficiency of EGFP to RGCs by microbubbles with ultrasound was significantly greater than the other groups, and no obvious damage was detected in the RGCs. CONCLUSION: Under irradiation of low-frequency ultrasound waves, ultrasound-mediated microbubble destruction was effective and resulted in safe transfection of the EGFP gene to the RGCs.
文摘Contrast enhanced ultrasonography(CEUS) has improved both the detection and characterization of foca liver lesions.It is now possible to evaluate in real time the perfusion of focal liver lesions in the arterial,porta and late contrast phases,and thus to characterize focal liver lesions with high diagnostic accuracy.As a result,CEUS has taken a central diagnostic role in the evaluation of focal liver lesions that are indeterminate upon computed tomography(CT) and magnetic resonance imaging.The combined use of second generation contrast agents and low mechanica index techniques is essential for the detection of liver metastases,and it now allows the examination of the entire liver in both the portal and late phases. Several studies have shown that using CEUS instead of conventional ultrasonography without contrast agents significantly improves sensitivity in detection of liver metastases.Furthermore,the detection rate with CEUS seems to be similar to that of CT.This review describes the clinical role of CEUS in detecting liver metastases,including details about examination techniques,features of metastases observed with CEUS,and clinical results and guidelines.
文摘AIM To perform a meta-analysis assessing the value of gadoxetic acid-enhanced magnetic resonance imaging(Gd-EOB-MRI)in detecting small hepatocellular carcinoma(HCC)(≤2.0 cm)in patients with chronic liver disease.METHODS Databases,including MEDLINE and EMBASE,were searched for relevant original articles published from January 2008 to February 2015.Data were extracted,and summary estimates of diagnostic accuracy indexes such as sensitivity,specificity,diagnostic odds ratio,predictive value,and areas under summary receiver operating characteristic curve were obtained using a random-effects model,with further exploration employing meta-regression and subgroup analyses.RESULTS In 10 studies evaluating 768 patients,pooled perlesion sensitivity of Gd-EOB-DTPA was 91%(95%CI:83%-95%),with a specificity of 95%(95%CI:87%-98%).Overall positive likelihood ratio was 18.1(95%CI:6.6-49.4),for negative likelihood ratio(NLR)of 0.10(95%CI:0.05-0.19)and diagnostic odds ratio of182(95%CI:57-581).Subgroup analysis suggested that diagnostic performance of Gd-EOB-MRI for sub-centimeter HCC(≤1.0 cm)detection was low,with a sensitivity of69%(95%CI:59%-78%).In studies with both Gd-EOBMRI and diffusion-weighted imaging(DWI)performed,Gd-EOB-MRI/DWI combination was more sensitive than Gd-EOB-DTPA alone,whether for small lesions(86%vs77%)or sub-centimeter ones(80%vs 56%).CONCLUSION A limited number of small studies suggested that GdEOB-MRI has good diagnostic performance in the detection of small HCC(≤2.0 cm)among patients with chronic liver disease,but relatively lower performance for detection of sub-centimeter HCC(≤1.0 cm).Combination of Gd-EOB-MRI and DWI can improve the diagnostic sensitivity of MRI.